Abstract: In the space of nine hours in August 2017, a terrorist cell armed with vehicles and knives launched two attacks on the city of Barcelona and the town of Cambrils, in Catalonia, Spain, killing 16 in the worst terrorist atrocity in Spain since the 2004 Madrid train bombings. New information obtained by the authors from judicial documents and interviews with investigators make clear the attacks could have been much worse. The 10-man cell, which included four sets of brothers all indoctrinated by an Islamic State-supporting cleric in the Catalonian town of Ripoll, initially planned to carry out ambitious vehicle bomb attacks in Barcelona and possibly Paris using TATP, but changed and accelerated their plans after they accidentally blew up their bomb factory. The Islamic State claimed the attackers were “soldiers of the caliphate,” but while newly disclosed information shows the network behind the Paris attacks targeted Barcelona for an attack in 2015, it is still unclear whether the group had any direct role in the August 2017 attacks.
On August 16, 2017, shortly before midnight, a massive explosion destroyed a house in Alcanar, a coastal town in the province of Tarragona, one of the four provinces that make up Spain’s northeastern region of Catalonia. As a result of the blast, two men inside the property died and a seriously injured man was brought to a hospital in nearby Tortosa.
Although authorities did not suspect any link to terrorism at the time, all three men were pro-Islamic State jihadis and part of a larger cell whose members were preparing to strike in Barcelona—and perhaps beyond.1 a The Alcanar house was the cell’s base of operations and its bomb factory, where members were making triacetone triperoxide (TATP). But it exploded accidently when two of the jihadis were drying and moving part of the extremely sensitive white crystalline powder known as “Mother of Satan.”2
With the loss of their bomb factory, other cell members changed their attack plans and improvised vehicle-ramming attacks in Barcelona and Cambrils the following day. After outlining how the group changed their plans to launch the most devastating attack on Spain in more than a decade, this article examines the evolution of the threat to Barcelona and the Catalan region. It then outlines what investigators and the authors themselves have uncovered about the Ripoll-based cell behind the attacks and the nature of its links to the Islamic State. Finally, the article looks at lessons that can be learned from the failure to thwart the attacks.
This article draws on nine sessions of interviews with police, intelligence, and judicial officials knowledgeable about the case, which were conducted by the authors between September and December 2017 in Barcelona and Madrid. Among the interviewees were officials from Catalonia’s autonomous police, or Mossos d’Esquadra (hereafter Mossos), Cuerpo Nacional de Policía (CNP, National Police), Guardia Civil (GC, Civil Guard), Centro de Inteligencia contra el Terrorismo y el Crimen Organizado (CITCO, Center for Intelligence on Terrorism and Organized Crime), Centro Nacional de Inteligencia (CNI, National Intelligence Center), and the Prosecutor’s Office of Audiencia Nacional (National Court).b This account also draws on legally available judicial and law enforcement documents—that is, criminal proceedings that are not subject to a gag order—as well as reliable open sources.
From Vans with Bombs to Vehicles without Bombs
According to Spanish investigators, the aim of the terrorists who were making TATP was to carry out a terrorist action of a “big magnitude.”3 c When their bomb-making preparations in Alcanar went wrong, far from paralyzing other cell members or prompting them to surrender to the authorities, the destruction of the bomb factory galvanized them into alternative, improvised action. It is possible this happened because they anticipated it was only a matter of time before the police would identify them after grilling their hospitalized co-conspirator or after checking information on the car and motorbike parked directly in front of the collapsed Alcanar property. It is also highly likely that at least one of the cell members became aware of the Alcanar blast and its consequences when, over the morning and afternoon of August 17, Mossos, having unproductively questioned the injured man, also attempted via phone calls to find out about the users of the two vehicles. At least one phone call, made on or very shortly before 3:00 PM on August 17, reached cell member Younes Abouyaaqoubd while he was driving a rented van on a beltway road about one hour away from Barcelona’s city center.4 e
Investigators believe that Younes Abouyaaqoub, as a result of this call, then decided to head toward downtown Barcelona. From that moment on, he and the remaining cell members redirected their attack efforts in a hurried, uncoordinated fashion. At about 4:30 PM, Younes Abouyaaqoub drove the van off Plaça de Catalunya into the popular Las Ramblas boulevard, which was packed with tourists and locals.f He plowed into pedestrians, zig-zagging for several hundred meters as he tried to hit as many people as possible. Thirteen people were killed immediately and over 100 injured.g Younes Abouyaaqoub then fled the scene on foot, walking through an adjacent market. Shortly afterward, he hijacked a car at knifepoint, stabbing the driver to death. Subsequently, he was able to break through a police checkpoint inside Barcelona, physically driving through a barrier that had been set up by Mossos after the attack, and drive away.
The car used by Younes Abouyaaqoub to escape was subsequently found abandoned south of Barcelona, in the Sant Just Desvern municipality. Four days later, on August 21, Mossos were tipped off by people who had spotted Younes Abouyaaqoub in a rural Subirats zone, some 40 kilometers away. He was then located in the countryside and shot dead. He was wearing a fake explosive belt, in what seems to have been a ploy to intimidate any person who might catch sight of the vest and to force police to shoot him dead so that he could attain martyrdom and what he hoped would be paradise.5 h
Almost nine hours after the Las Ramblas vehicle-ramming attack, at around 1:15 AM on August 18, a new car, with five additional cell members inside wearing fake suicide belts, plowed into another pedestrian promenade in the seaside resort town of Cambrils in the province of Tarragona, 120 kilometers from Barcelona.i The car, owned by a brother of one of these terrorists, then crashed into a Mossos vehicle. The occupants jumped out and went on a stabbing spree using large knives and an axe acquired four hours earlier.6 j A woman was killed and several other people injured before the terrorists were shot dead by a policeman.7 The group had rented a second van, but a traffic collision the previous afternoon prevented them from using it in an attack, in addition to or instead of the car they finally used in Cambrils.8 k
Altogether, the two terrorist attacks in Barcelona and Cambrils left 16 dead—the eight dead jihadis not included in this total—and about 140 people wounded.l The existing evidence indicates the terrorist cell had planned a far more ambitious and potentially more deadly operation. Their original intent included turning the two vans they had rented into vehicle-born improvised explosive devices (VBIEDs). Their plan had been to load the vans with large quantities of TATP together with flammable gas canisters to perpetrate a major attack or series of attacks, most likely in Barcelona but maybe elsewhere in Spain, too, or even France. It seems the terrorist cell intended for the gas canisters to amplify the explosion. But technically, this would unlikely have been the case. The canisters would nevertheless have become shrapnel during the explosion.
It is known that three cell members had visited a car rental company in the city of Sabadell in the province of Barcelona on August 16—the day before the accidental Alcanar explosion—where they rented two vans. One of these two vehicles was used in the Las Ramblas attack.9 Around 120 canisters of butane and propane were stored in the Alcanar house. Other material found in its wreckage included some 500 liters of acetone, a significant quantity—340 liters10—of hydrogen peroxide, as well as bicarbonate. Nails to create shrapnel were also retrieved, as were push-buttons to initiate the devices. At least one viable (because of its configuration) explosive suicide vest was retrieved as well as fake ones.m Traces of TATP were also found. The terrorists had begun filling metal cylinders with shrapnel and the TATP they had made thus far.11 Investigators told the authors that the terror cell had enough precursor chemicals to make more than 200 kilograms of TATP, perhaps up to 250 kilograms.
Most of these materials and substances were purchased on August 1, 2, and 16.12 On the evening of August 16, just hours before the Alcanar bomb factory exploded, white pillowcases and cable ties were acquired by cell members in Sant Carles de la Ràpita in the province of Tarragona to store the TATP.13 It was confirmed to the authors that a depiction of the Islamic State flag was marked with a pen on at least one of these pillowcases. These acquisitions and the rental of two vans the same day suggest that the terrorists initially planned a large-magnitude attack or attacks to take place within one week or so of August 17. The terrorists were waiting on all 200 to 250 kilograms of TATP to be prepared. The two vans were rented for seven days, starting August 16.
Investigators believe the cell’s original targets were in Barcelona but possibly elsewhere, too. Considering the lethal resources assembled by the terrorists and their lethal intent, the death toll could have reached hundreds had they not accidently blow up their bomb factory in Alcanar. There were media reports that a suspect had revealed in court that the Sagrada Familia church in Barcelona was among the targets.14 In reality, the judicial declaration in question from the cell member surviving the Alcanar blast was vague on this point, referring to “monuments and churches, such as the Sagrada Familia” as targets.15 The individual in question was not suspected to be a senior member of the cell and did not apparently have knowledge of specific targets. Nevertheless, the Sagrada Familia was one of the locations—marked by means of Google maps searches—that was found in a cellular phone used by members of the cell, in addition to the Nou Camp, the soccer stadium of Barcelona Football Club.n
To get a sense of the potential devastation such a large amount of high explosives could have caused, it is worth noting that the two TATP suitcase bombs that were detonated by Islamic State suicide bombers at Brussels airport likely weighed under 20 kilograms each.o Two vans each loaded with over 100 kilograms of high explosives had the potential to inflict significant structural damage in buildings and/or cause very high casualties in crowded outdoor urban areas.
Preceding Plans to Strike in Barcelona
Between January 2013 and September 2017, the four Catalan provinces accounted for 33 percent—that is, 76—of all suspected jihadi terrorists arrested (222) or deceased (eight) in Spain.p Only 27 percent of Spain’s Muslims live in Catalonia,16 indicating a higher rate of violent extremism among Muslims in Catalonia than in Spain as a whole. This seems to correlate with a much higher salafi presence in the region as compared to the rest of Spain. In 2016, one-third of all 256 Islamic worship places and centers in Catalonia were controlled by salafis, more than double the number in 2006.17 q
The radicalization rate runs particularly high in Barcelona. The province accounted for over one-fifth—22 percent, or 53—of all jihadis arrested or deceased in Spain as a result of terror-related activity during this 2013-2017 period, though just 17 percent of Spain’s Muslims live in that province.18 Between January 2013 and September 2017, Barcelona’s province had 1.6 jihadis per every 10,000 Muslims. Inside Catalonia, only the province of Girona has a higher rate of radicalization, with 1.8 jihadis per every 10,000 Muslims.r
Catalonia has been a center of jihadi activity since the 1990s. It was in Barcelona, in 1995, that a jihadi was arrested for the first time in Spain.s Cambrils—and nearby Salou—is where Mohammed Atta, assisted by a jihadi resident in the area, met Ramzi Binalbish two months ahead of 9/11.19 In January 2003, an al-Qa`ida-linked cell was broken up in the provinces of Barcelona and Girona; it was preparing chemical attacks by means of a product referred to as “homemade napalm” and found to be in possession of mobile phones identical to those used to trigger the 2004 Madrid bombs and modified in the same way.20 Some members of the Madrid bombing network escaped to Iraq through Santa Coloma de Gramanet town in Barcelona province, where facilitators linked to the Moroccan Islamic Combatant Group (GICM) had a safe house.21
Barcelona itself was the target of a terrorist plot when a planned attack on its metro was thwarted in January 2008.22 The detained suspects had links to al-Qa`ida-aligned Tehrik-e-Taliban Pakistan (TTP), whose spokesman acknowledged responsibility for the plot.23 Eleven cell members, including longtime residents of the city and more recent arrivals from Pakistan, were found guilty of the plot.24 During this period, Barcelona also produced a high proportion of Spain’s jihadis. Between 2004 and 2012, four out of every 10 jihadis convicted in Spain resided in and were arrested in the province of Barcelona.25
There has been a string of thwarted plots in Barcelona in the past three years. On April 2015, Mossos agents arrested, in three locations in the province of Barcelona and a fourth one in the province of Tarragona, eight members of an Islamic State-inspired cell composed of Moroccan nationals and converted Spaniards.26 They were preparing attacks in Barcelona. In spite of the somewhat amateurish character of these preparations, they had amassed significant amounts of precursor chemicals needed to make explosives and had obtained weapons.27 Their choice of targets were the Plaça d’Espanya, the autonomous Parliament of Catalonia, and Montjuïc Olympic Stadium.28
But Catalonia’s capital was not solely in the crosshairs of Islamic State-inspired cells. Not only was Barcelona a main target of Islamic State external operations command, when still directed from Raqqa, but it was the first Western European city designated by the organization as a target for a major, large-scale attack. The Islamic State operative at the center of the plot was Moroccan national Abdeljalil Ait el-Kaid, who resided in the town of Torrevieja in the province of Alicante within the Valencian Community region, south of Catalonia before joining the Islamic State in Syria in September 2014.29 Guardia Civil officers had detected el-Kaid’s radicalization and alerted Spanish security authorities about his disappearance.30 El-Kaid also attracted the attention of Mossos when trying, from Raqqa, to seduce and recruit a young Muslim woman living in Barcelona, through social media and instant messaging applications.31 This and additional information shared by foreign intelligence services led Spain to issue an international arrest warrant for el-Kaid.
In mid-2015, el-Kaid departed from Syria for Europe with fellow French Islamic State recruit Reda Hame. Hame had traveled to Syria early the same month but was almost immediately recruited to return to France to launch an attack by the Belgian Islamic State operative Abdelhamid Abaaoud, who two months later32 would himself return to Europe to lead the attack team that carried out the November 2015 attacks in Paris. Before Hame left for Europe, Abaaoud had promised him he would receive the rewards in paradise of two martyrs for carrying out a separate attack.33 El-Kaid used exactly the same argument when attempting, from Syria, to persuade the previously mentioned young Muslim woman living in Barcelona to kill “infidels” there.t
El-Kaid was arrested in June 2015 in Warsaw, Poland, in transit from Istanbul.u Handed over to Spain in July 2015, el-Kaid was imprisoned and charged with terrorism offenses.34 Trained in arms and explosives while in Syria, he was among the Islamic State recruits in Abaaoud’s circle there and was sent back by Abaaoud to operate in Western Europe.35
At the time of his arrest, el-Kaid had been on his way to Spain on a funded mission to prepare attacks in Barcelona and, according to investigators, had envisioned carrying them out in September 2015. These plans were disrupted as a result of his detention. But another group within the same Islamic State attack network succeeded in perpetrating, two months later, the November 2015 attacks in Paris.36 Investigators have learned the disrupted plot to strike Barcelona was meant to be similar to the one later executed in Paris and was meant to also involve operatives from France and Belgium with whom el-Kaid was meant to link up. As with the Paris attacks, the Barcelona plan was to involve the use of Kalashnikov rifles and bombs in multiple crowed spaces such as concert halls, dining areas, and sports events. The two plots were meant to be part of the same Islamic State-directed terror campaign in Western Europe, which illustrates the fact that the francophone cadre of the Islamic State’s foreign fighters were the most actively involved in external operations.37
Imam Es Satty and the Ripoll Cell
The terrorist cell behind the August 2017 attacks was composed of at least 10 men.v Two of them—cell leader Abdelbaki Es Satty and Youssef Aalla—died in the Alcanar explosion on August 16; six others—Mohamed Hichamy, Houssaine Abouyaaqoub, Said Aalla (younger brother of Youssef), Moussa Oukabir, Omar Hichamy (younger brother of Mohamed), and Las Ramblas attacker Younes Abouyaaqoub (elder brother of Houssaine)—were shot dead by the police, the former five on August 18 in Cambrils and Younes Abouyaaqoub on August 21 near Subirats. Two alleged cell members were arrested. Mohamed Houli Chemlal, who was injured in the Alcanar blast, was arrested on August 18 in Tortosa, and Driss Oukabir (elder brother of Moussa) was arrested the same day in Ripoll.w
Ripoll, a small town of around 11,000 people in the foothills of the Pyrenees near the French border, is where nine of the 10-man cell resided. The tenth was domiciled in Ribes de Freser, a village 14 kilometers from Ripoll. Their average age at the time of the August attacks was 23. All were in their 20s or younger,x apart from the cell’s 45-year-old ringleader Es Satty, who was born in Madchar, Morocco, in 1973, some 100 kilometers south of Tangier. In the years leading up to the attack, Es Satty preached as an imam in Ripoll.
Eight of the nine Es Satty acolytes were Moroccan nationals, and only one of them was a Spaniard. Yet all nine were second-generation descendants of Moroccan immigrants, and all nine were born or raised in Spain. Two were born in Spain—in Ripoll and in Melilla—and seven were born in Morocco and then brought to Spain as children.y As legal residents of Spain, they were all entitled to the same public health and education services as any other citizen. Additionally, all nine benefited from a program to prevent social exclusion among people with migrant backgrounds.z Seven out of the nine had completed secondary education, and of those, six attended or were attending a professional training program. On or before August 2017, Las Ramblas attacker Younes Abouyaaqoub and Mohamed Hichamy (one of the Cambrils attackers) were employed as skilled metallurgical workers.38 Hichamy received a monthly salary of €2,000, and he was benefiting from public housing, as were most other cell members and their families.39 Another of the Cambrils attackers, Omar Hichamy, had a similar kind of job.40 The Alcanar blast survivor Mohamed Houli Chemlal repeatedly refused employment at the same firm where Younes Abouyaaqoub and Mohamed Hichamy worked.41 Cambrils attackers Moussa Oukabir and Said Aalla were still enrolled in professional training programs at the time of the attack.42 Three members of the cell had previous criminal records for petty crime: Youseff Aalla (who died in the Alcanar explosion), Houssain Abouyaaqoub, and Driss Oukabir (the man arrested in Ripoll).43
Yet, teachers, social workers, school friends, and others in Ripoll who knew these young men tended to have the perception that they were ‘good boys’ and expressed shock that they had become terrorists. Their circle of friends was not limited to Moroccans, and they were widely seen in Ripoll as being well or completely integrated into the local community.aa This strongly suggests these young men became socially disenfranchised not as a result of exclusion, segregation, or deprivation, but because of the influence of their local imam Es Satty, who acted as an in-person radicalizing agent. Es Satty first worked as an imam in Ripoll for a short time in 2015 in what was then the only Islamic place of worship there and then, from June 2016 on, in a new prayer center.44 Between January and March of the same year, he had traveled to Belgium, reportedly looking for a job as an imam in the Brussels municipality of Vilvoorde,45 an area in which one of the most significant clusters of Belgian Islamist extremists reside.46
By the time Es Satty arrived in Ripoll in 2015, he had already been immersed in jihadi circles in Spain for a decade. After he migrated from Morocco to Spain in 2002 at the age of 30, he settled for a while in the Andalusian province of Jaén where he shared a residence with an Algerian man who would die in 2003 as a suicide bomber in Iraq.ab Es Satty next moved to Vilanova i la Geltrú town, in the province of Barcelona, sharing lodgings with the then head of a cell linked to the now-extinct GICM.ac Es Satty was the focus of counterterrorism investigations but, unlike others he was associated with, never arrested. He served a prison sentence in Castellón between 2010 and 2014 after being convicted of drug smuggling.47 ad Before Es Satty took over the position of imam in Ripoll, it is known that he attended salafi meetings held in Catalonia.48
When radicalizing and recruiting the young Muslims of Ripoll, Es Satty benefited from preexisting family and social ties among those who joined his cell.ae Out of the nine he recruited for the attack, there were four pairs of brothers, with one set of brothers cousins with another set of brothers.af The nine were all neighbors, attended the same educational institutions, and participated in the same recreational activities.49 At first, investigators believed that cell members had undergone very rapid radicalization processes. But a cousin of two of the terrorists reported that Es Satty had been meeting with some of them discreetly, outside his worship place, for no less than a year before the attacks.ag Members of the future attack cell were also indoctrinated by Es Satty during meetings at a rural compound in Riudecanyes in the province of Tarragona. In the years before they started to become radicalized, these nine young men were not known for their religiosity,50 with the exception of Cambrils attacker Mohamed Hichamy.ah Subsequently, they all embraced a fundamentalist interpretation of Islam.51 The pattern was the elder brothers became radicalized first, then the younger siblings.
Age and kinship appear to have been the determinant factors in how the cell was structured. Under Es Satty’s charismatic authority, elder brothers such as Las Ramblas attacker Younes Abouyaaqoub, Cambrils attacker Mohamed Hichamy, the alleged surviving cell member Driss Oukabir, and most probably Youssef Aalla played central operational roles or were positioned in the intermediate tier of the group, along with Alcanar blast survivor Mohamed Houli Chemlal (who was the only one of Es Satty’s recruits not to have a sibling in the cell). The evidence so far uncovered by investigators suggests the younger brothers, including Houssaine Abouyaaqoub, Omar Hichamy, Moussa Oukabir, and Said Aalla, had more peripheral roles in the cell and were controlled and pressured into full compliance by their older siblings.
Contact with the Islamic State?
Amidst the debris of the Alcanar property, a green-colored notebook was found with the name of Abdelbaki Es Satty on the first page, suggesting it belonged to the cell leader. In a sheet inside the notebook, handwritten in Arabic, cell members are portrayed as “soldiers of Islamic State in the land of al-Andalus.”52 On August 17, 2017, before the attack in Cambrils, the Islamic State-affiliated Amaq News Agency issued a short statement on the Telegram messaging app claiming that “perpetrators of the attack in Barcelona were Islamic State soldiers and the operation was carried out in response to calls for targeting coalition countries.”53 Responsibility for the attack in Cambrils was subsequently claimed by the same outlet.54
On August 23, 2017, the Islamic State’s Wilayat al-Khayr disseminated a video celebrating “The Raid of Barcelona,” featuring two Spanish-speaking militants based in Syria.55 One of the young Islamic State fighters featured was the Córdoba-born eldest child of Tomasa Pérez, a Spanish woman who converted to Islam and married to a Moroccan jihadi currently imprisoned in Morocco. Pérez relocated to Syria in 2014 alongside her five sons and a daughter.56 In the video, Pérez’s son, 22-year-old Muhammad Yasin Ahram Pérez, boasts, in rather rudimentary Spanish, “Allah willing, al-Andalus will be back on track as land of the caliphate.”57 The following day, a new release by the Islamic State’s al-Naba news bulletin included infographics of the attacks in Catalonia next to a bloodied image of Barcelona’s famous Sagrada Familia church.58
Three weeks after the attacks, the Islamic State featured another picture of the Sagrada Familia in issue 13 of its propaganda online magazine Rumiyah. The article again described the perpetrators as “a group of Islamic State soldiers” and the attacks as “a blow to the tourism sector” in Spain. It claimed the country was targeted because it had taken part in “the war against the Islamic State” by providing training to the Iraqi Army and participating in the international coalition to fight the Islamic State.59
Thus far, no evidence has yet come to light that the Barcelona cell was in touch with an Islamic State cybercoach in Syria, Iraq, or somewhere overseas. Perhaps tellingly, unlike after the November 2015 Paris attacks, the Islamic State has provided no additional particulars about the attackers beyond calling them their soldiers, nor has it aired any video recorded by the attackers as it did after the December 2016 Berlin attack. The exact nature of the relationship between the Ripoll cell and the Islamic State organization remains unclear. On the one hand, Islamic State communiques disseminated in the aftermath of the Barcelona and Cambrils attacks, including the article in Rumiyah, contained a number of inaccuracies,ai suggesting lack of direct contact between the cell and the Islamic State propaganda apparatus in Syria.
On the other hand, international trips made by some Ripoll cell members in the years and months before the attack open up the possibility that the group developed some links to European networks connected to the Islamic State. Las Ramblas attacker Younes Abouyaaqoub, who was one of the senior figures in the cell, visited France at least three times between July and December 2016. He last traveled by car to Paris—accompanied by one to perhaps three other unidentified individuals—on August 11 and 12, 2017, less than one week before the attacks.60 aj Mohamed Hichamy and Youseff Aalla, also senior members of the cell, traveled to Zurich in December 2016.61 In addition, Driss Oukabir, one of the four elder brothers inside the cell, flew to Tangier in northern Morocco from Barcelona and back, between August 5 and August 13, 2017.62
Except for some aspects of Driss Oukabir’s trip to Morocco (he visited an uncle in Fnideq, but his relatives noted he strangely did not visit his father who lives in his native village), the exact purposes of all of these travels remain unclear.63 What investigators have established, however, is that at a certain point a member or members of the Ripoll cell, while in Paris, purchased a video camera and taped the Eiffel Tower.64 In September 2017, Spanish authorities communicated this finding to their French counterparts.65 The French government assessed that Paris could have also been a target of the Ripoll cell, and this prompted the decision to install a glass fence around the Eiffel Tower to protect the area from terrorist attacks utilizing firearms and vehicles.66 The footage of the Eiffel Tower was included in a video recording—found among the debris in Alcanar—in which Mohamed Hichamy appears inside the safe house, holding TATP in his hands and saying, in Arabic, “Spaniards, you are going to suffer.”67
Aside from that, U.S. intelligence—and more precisely, the National Counterterrorism Center (NCTC)—shared directly with Mossos and statewide police agencies in Spain a threat bulletin on May 25, 2017, less than three months before the attacks in Barcelona and Cambrils. It contained the following note: “Unsubstantiated information of unknown veracity from late May 2017 indicated that the Islamic State of Iraq and ash-Sham (ISIS) was planning to conduct unspecified terrorist attacks during the summer against crowded tourist sites in Barcelona, Spain specifically, La Rambla Street.”68 The head of Mossos and, before him, both the president of the Catalonian autonomous government and the regional minister of interior initially denied receiving this information. Mossos subsequently conceded to having received the brief note, stating it was of “low credibility,” and public security arrangements in the center of Barcelona, a sole responsibility of Mossos and local police (Guàrdia Urbana), were not, therefore, modified.ak
The Ripoll cell members financed the above-mentioned trips and other activities not only with their own income but also with money obtained with the sale of gold. Mossos discovered that they obtained around €1,200 from the sale of stolen gold jewelry.69 The money was used to purchase butane gas canisters stored in the safe house of Alcanar. Investigators have also established that they bought part of the cylinders in a staggered way and made some orders online so as not to raise suspicions.70 This was part of the elaborate measures the cell took to prevent their plot from being detected. The residence in Alcanar that the cell used as a bomb factory was an abandoned property where they were squatting. The electricity they used was illegally taken from the main supply.71
The members of the Ripoll cell showed remarkable skills in forming the group and planning the attack without arousing suspicions from security services or the local community. Es Satty’s leadership, given his longstanding experience in jihadi milieus, may explain the careful, even meticulous conduct of his followers, assisted by elder brothers in imposing rules of conduct onto the younger members. The changes of the mood and habits of the young men, far from raising alarm within the Muslim community or inside their own families, were seen as either irrelevant or positive.72 This may have been a product of a lack of awareness inside the Muslim community and wider society about pointers toward radicalization.
But failure to detect the Ripoll cell and thwart the Barcelona and Cambrils attacks has raised many questions about counterterrorism capacity inside Catalonia. No fewer than three law enforcement agencies have full counterterrorism competences in the region: on the one side, the autonomous police, Mossos; on the other side, two statewide police forces, the Cuerpo Nacional de Policía (CNP, National Police) and the Guardia Civil (GC, Civil Guard).al Between January 2013 and July 2017—the month before the Barcelona and Cambrils attacks—33 police operations against jihadi terrorism were conducted in Catalonia. The CNP conducted 15 of these operations and arrested 29 suspects (45 percent of the total), the GC conducted 11 and arrested 19 (29 percent), and Mossos conducted seven and arrested 17 (26 percent).73
Despite these results, the work of these security services in preventing terrorism was hindered both by insufficient implementation of existing legislation on the control of explosive precursors in the whole of Spain and by deficiencies in coordination among security agencies. The Ripoll cell found no obstacles in purchasing some 500 liters of acetone—to make TATP—in different locations of Catalonia and the town of Vinaroz, 20 kilometers south of Alcanar, in the Valencian Community region.am Despite a 2013 European Union regulation on the sale of potential explosive precursors, which is directly applicable to member states, its actual implementation in Spain proved inadequate when members of the Ripoll cell purchased the substances they needed to make TATP.an
Coordination and exchange of information between the above-mentioned counterterrorism services is widely acknowledged among practitioners themselves as being limited, if not poor. This is despite the existence of the Centro de Inteligencia contra Terrorismo y Crimen Organizado (CITCO, Center for Intelligence against Terrorism and Organized Crime), which is officially charged with counterterrorism coordination across the whole of Spain. Indeed, following the Barcelona and Cambrils attacks, the judge at the National Court in charge of the criminal proceedings instructed CITCO to coordinate all police investigations on the case, to which all security services with counterterrorism competences in the Catalonian provinces must have access.74
Traditional rivalries and inter-organizational competition explain part of the problem. But it is the authors’ belief, shared by most but not all of the officials interviewed for this article, that secessionist tensions in a highly divided and polarized Catalonia—where pro-independence parties in control of the autonomous executive have taken defiant stances toward the central government of Spain—have complicated counterterrorism cooperation between Mossos and statewide police agencies. These shortcomings are particularly concerning because ever since June 2015, the terror alert level in Spain has been at four out of five, meaning a “high risk” of terrorist attacks.75 Furthermore, Catalonia and Barcelona have been the most salient regional and provincial centers of jihadi activity, respectively, in Spain since 2013.76
One example of how well-intentioned but flawed police exchanges, domestically and internationally, precluded Mossos and state security services from introducing a timely scrutiny of Es Satty, which might have prevented the Ripoll cell from forming, came on March 8, 2016. On that day, a Mossos officer responded by email to a question he had received from a Belgian local police officer in Vilvoorde about a radicalized individual named Es Satty who had come from Catalonia and was looking for a position as an imam in the city. The two policemen knew each other from a professional seminar they had both attended previously, and their contact did not follow official channels. The Mossos officer replied that there was no information to tie Es Satty to Islamist militancy, but he did so without consultations with other services.77 In fact, CNP and GC had investigated Es Satty a decade earlier. The Belgian local police officer likewise neglected to communicate about the case with the Belgian Federal Police, which would have allowed for the formal procedure between Belgian and Spanish authorities for counterterrorism information exchange.
This is not to say it would have been easy to detect the cell’s plotting. Es Satty was skilled at concealing the full extent of his violent extremism from authorities. This was evidenced when CNI agents approached him while he was serving a sentence in a Castellón penitentiary a few years before the attacks but found no cause for alarm, despite following usual protocols with individuals in prison who had jihadi contact in the past.78 Furthermore, Es Satty avoided administrative expulsion from Spain upon his release from the penitentiary because a local judge, never briefed on the subject by any of the state security agencies, annulled the expulsion order citing Es Satty’s efforts to integrate into Spanish society and the judge’s own concerns about human rights protection.79
Due to the unprecedented levels of jihadi mobilization experienced over the past six years in Spain and Western Europe as a whole,ao more terrorist incidents including of the kind both initially envisioned and carried out by the Ripoll cell are likely to be repeated in the country and across the European Union. What stood out about the Ripoll cell, however—in addition to being formed by apparently well-integrated, second-generation young Muslims and being led by an imam who had been part of the jihadi scene for more than a decade—was its size. It shows that even in the wake of the Paris and Brussels attacks, which were carried out by attack groups of comparable size, a large terrorist cell can still plan ambitious attacks without being detected. It also illustrates that jihadis in Europe continue to want to plot bomb attacks, including with difficult-to-make TATP, but have a range of lower-tech ways to otherwise create carnage. A terrorist cell of 10 can, after all, carry out 10 vehicle-ramming attacks. CTC
Fernando Reinares is Director of the Program on Global Terrorism at Elcano Royal Institute as well as Professor of Political Science and Security Studies at Universidad Rey Juan Carlos, both in Madrid. He is also Adjunct Professor of Security Studies at Georgetown University in Washington, D.C. His latest books include The Evolution of the Global Terrorist Threat: From 9/11 to Osama bin Laden’s Death (edited with Bruce Hoffman) and Al-Qaeda’s Revenge: The 2004 Madrid Train Bombings, both published by Columbia University Press. Follow @F_Reinares
Carola García-Calvo is Senior Analyst on International Terrorism and member of the Program of Global Terrorism at Elcano Royal Institute, as well as Associate Lecturer on Terrorism Studies at Universidad Pontificia Comillas, both in Madrid. She is Academic Coordinator of the European Union project MINDb4Act to develop a comprehensive approach to violent radicalization, under the Horizon 2020 Program. She co-authored, with Fernando Reinares, Estado Islámico en España, published by Real Instituto Elcano. Follow @Carolagc13
[a] During an initial site inspection, officers of the Catalonian autonomous police, known in the vernacular as Mossos d’Esquadra, dismissed the explosion as related either to the unauthorized refill of butane canisters for nearby campers or to an illegal drugs laboratory.
[b] The authors wish to express their gratitude for the time and attention of all of their interviewees. Information derived from the meetings the authors had with these individuals is presented as coming from them jointly and in an undifferentiated fashion. As agreed with the interviewees, concrete information will not be attributed to any of them in particular. Unless otherwise indicated, the substantive information contained in this article emanates from these individual and group interviews. Because of the gag order on the criminal proceedings opened after the Barcelona and Cambrils attacks, it is important to state that explicit references to these court proceedings are not related to contact with any member of the police and intelligence services. Also, the authors wish to thank Álvaro Vicente, research assistant at the Program on Global Terrorism at Elcano Royal Institute, for his outstanding help in collecting and contrasting open sources.
[c] TATP was used by Islamic State militants in the attacks in November 2015 in Paris and March 2016 in Brussels, as well as in the May 2017 Manchester bombing. It was also used in al-Qa`ida plots against London on July 21, 2005, and New York in September 2009. Inside Spain, the 2004 Madrid attack conspirators considered using the substance before opting for another form of explosives. See Fernando Reinares, Al Qaeda’s Revenge: The 2004 Madrid Train Bombings (New York: Columbia University Press, 2017), p. 146; Neville Dean, Caroline Gammell, and John Bingham, “21 July bombers planned London carnage,” Press Association, January 15, 2007; and “Najibullah Zazi Pleads Guilty,” U.S. Department of Justice, February 22, 2010.
[d] The registered owner of the car parked in front of the Alcanar house was Younes Abouyaaqoub’s younger brother, Houssaine.
[e] It is known that Mossos also contacted an older brother of Younes Abouyaaqoub. See Patricia Ortega-Dolz, “Los Mossos buscaban a Younes, el autor de la matanza de Las Ramblas, horas antes de que la llevara a cabo,” País, November 20, 2017.
[f] At about the same time, a second explosion further shook the remains of the Alcanar house. Police and fire services were on the site at the time.
[g] One of those seriously injured during the Las Ramblas attack died 10 days later (August 27) after being hospitalized. Among the 14 killed and over 100 injured, there were individuals from at least 35 countries. See “Muere una mujer alemana de 51 años herida en el atentado de La Rambla y se elevan a 16 las víctimas,” Mundo, August 27, 2017, and “Las víctimas del atentado en Barcelona,” País, August 21, 2017.
[h] There has been a public debate in Spain as to whether or not the killing of Younes Abouyaaqoub, in the circumstances the two Mossos agents found him, was proportionate.
[i] Before they reached the site, they had been looking for a site in the vicinity with more crowds but were unable to locate or access such an area.
[j] The attack in Cambrils resembles the one in London Bridge and Borough Market area, also in London, on the night of June 3, 2017, where the terrorists were wearing what looked like explosive vests, but these were later established to be fake. See “London terror attack: Terrorists wore fake suicide vests, police say,” Independent, June 4, 2017.
[k] The one among these five terrorists who had rented this second van on August 17 from a rental company in Parets del Vallès, province of Barcelona, was involved in a traffic collision on highway AP-7, very near Cambrils, at 3:25 PM that day. He hurried to leave the site on foot and was later picked up in a nearby location by other cell members.
[l] Fatalities included persons of nine different nationalities: six Spaniards, three Italians, two Portuguese, one Belgian, one dual Australian and British, one German, one American, and one Canadian.
[m] It was not clarified to the authors whether TATP was found inside the viable suicide vest.
[n] A soccer match between FC Barcelona and Seville’s Real Betis was scheduled (and took place as planned) in Barcelona’s Nou Camp stadium on Sunday, August 20. See Manuel Cerdán, “La policía descubrió en un móvil que los yihadistas del 17-A querían poner una furgoneta bomba en el Camp Nou,” Okdiario, January 19, 2018.
[o] The suitcase bomb that failed to explode at Brussels airport on March 22, 2016, reportedly weighed 35 pounds (16 kilograms). Doug Stanglin and Jane Onyanga-Omara, “One 35-pound bomb in Brussels attack failed to go off; suicide note found,” USA Today, March 23, 2016.
[p] Calculations are made on the basis of the Elcano Data Base on Jihadis in Spain (EDBJS).
[q] French authorities are very concerned about the very significant salafi presence in Catalonia, which is a frontier region between Spain and France, as revealed by former French Prime Minister Manuel Valls during an interview published by El Mundo in mid-December 2017. Carlos Segovia, “Manuel Valls: ‘Los salafistas han apostado por Cataluña y no se habla de ello ahora,’” Mundo, December 13, 2017.
[r] The same rate for the whole of Spain is of 1.0 per 10,000 Muslims who reside in the country—North African enclaves of Ceuta and Melilla included.
[s] He was convicted the year following his detention. See Audiencia Nacional, Sala de lo Penal, Sección Segunda, Sentencia 7/1996.
[t] “Infidels must be killed. And you stay with the rewards of two martyrs,” El Kaid insisted to her. See Antonio Baquero, “El Estado Islámico a una joven en Catalunya: ‘Vas a una reunión y empiezas a matar a saco,’” Periódico, March 5, 2017.
[u] Reda Hame was arrested in the Paris area in August 2015. Rukmini Callimachi, “How ISIS Built the Machinery of Terror Under Europe’s Gaze,” New York Times, March 29, 2016.
[v] Investigators believe the 10-man cell likely benefited from the collaboration of at least two others. One of them, a Moroccan, was arrested on September 22 in Vinaroz, a town in the province of Castellón just eight kilometers south of Alcanar. The second individual remains on conditional bail, as evidence of offenses were not considered solid enough at the time of his arrest on August 17, 2017, in Ripoll. Ministerio del Interior, Oficina de Comunicación y Relaciones Institucionales, Nota de Prensa, September 22, 2017. See Diligencias Previas 60/2017, Auto of August 22, 2017, pp. 13-14.
[w] On August 22, the judge in Spain’s National Court leading the investigations on the case ordered the two surviving alleged co-conspirators to be remanded in custody. They were charged with murder, possession of explosives, and belonging to a terrorist organization, among other crimes. See Audiencia Nacional, Juzgado Central de Instrucción núm. 4, Diligencias Previas 60/2017, Auto of August 22, 2017, p. 13.
[x] His nine followers were aged between 17 and 28, with a total of four still teenagers at the time of the attacks.
[y] Of those born in Morocco, four were born in Mrirt, two in Aghbala, and one in Naour.
[z] The program of the Catalonian autonomous administration intended to facilitate the acquisition of linguistic and digital skills as well as, in the case of children and teenagers, assisting in tasks related to school performance and professional training, among other initiatives. See Generalitat de Catalunya, Departament de Treball, Afers Socials i Famílies, Programa Òmnia, and Sílvia Oller, “Casi todos en Ripoll hemos compartido espacio con Moussa,” Vanguardia, August 19, 2017.
[aa] An acquaintance of Younes Abouyaaqoub said he was “unable to lead anything,” and a local social educator remarked how “responsible” he was. See Jordi Pérez Colomé, Marta Rodríguez, and Patricia Ortega-Dolz, “Cómo el imán de Ripoll creó una célula yihadista,” País, August 21, 2017; “¿Cómo puede ser, Younes? No he visto a nadie tan responsable como tú…,” Vanguardia, August 22, 2017. On the Oukabir brothers, a social worker pointed out that they belonged to “a large family which was integrated in our town.” See David López Frías, “En el nido de víboras de Ripoll: en esta casa planearon la masacre los hermanos Oukabir,” Español, August 19, 2017.
[ab] The Algerian man, Bellil Belgacem, traveled from Spain to Iraq and blew himself up on November 12, 2003, in an attack against a base of Italian Carabineri in the city of Nasiriyya, which was claimed by the group that later became al-Qa`ida in Iraq. See Mohammed M. Hafez, Suicide Bombers in Iraq: The Strategy and Ideology of Martyrdom (Washington, D.C.: United States Institute of Peace, 2007), p. 155.
[ac] This cell operated out of a place of worship. It was connected to Ansar al Islam, a then al-Qa`ida-aligned jihadi group in Kurdistan and from late 2004, al-Qa`ida’s branch in Iraq. See Dirección General de la Policía, Comisaría General de Información, Unidad Central de Información Exterior, Diligencia 466, January 9, 2006, pp. 52-53 and 86. Personal ID documents belonging to Abdelkabi Es Satty, next to those belonging to other people including Bellil Belgacem, were found at the beginning of 2006 in the residence of a jihadi ringleader in Santa Coloma de Gramanet. See Audiencia Nacional, Sala de lo Penal, Sección Primera, Sentencia 3/2010, p. 70.
[ad] While in prison in Castellón, he became close to a convicted member of the 2004 Madrid bombing network, namely Rachid Aglif. See “El imán de Ripoll trabó amistad en prisión con un terrorista del 11-M,” País, August 20, 2017.
[ae] The drivers of radicalization seen with the Cambrils cell fit the dominant pattern seen in Spain. As the authors pointed out in a 2017 article for this publication, “violent radicalization [in Spain] leading to involvement in jihadi terrorism appears to be highly contingent upon two key factors of what has been termed ‘differential association,’ namely contact with radicalizing agents and pre-existing social ties with other radicalized individuals.” The study found that “the importance of contact with a radicalizing agent points toward the relevance of ideology in the development of jihadi terrorists, while the significance of pre-existing social ties indicates the relevance of communitarian bonds with local networks, which facilitate terrorist radicalization and recruitment.” Fernando Reinares, Carola García-Calvo, and Álvaro Vicente, “Differential Association Explaining Jihadi Radicalization in Spain: A Quantitative Study,” CTC Sentinel 10:6 (2017).
[af] In recent years, many terrorist cells in the West have involved siblings, including in the 2013 Boston bombings, the January 2015 Charlie Hebdo attacks, and the November 2015 Paris attacks. Mohammed Hafez noted in this publication that “tightening security environments are encouraging jihadis to turn increasingly to the family unit for recruits. This phenomenon complicates efforts to detect, monitor, and prevent violent radicalization. Kinship recruitment, which is difficult for security agencies to observe, is facilitated by several psychological mechanisms that bind individuals together on the path to extremism. Importantly, it deters ambivalent recruits from defecting to the authorities for fear of damaging their own valued relationships.” Mohammed Hafez, “The Ties that Bind: How Terrorists Exploit Family Bonds,” CTC Sentinel 9:9 (2016).
[ag] His testimony reads as follows: “They used to meet in the van, parked in an out-of-the-way street and they stayed there for two hours or more. If someone walked by close to them, they stopped talking and started looking at their mobile phones”. See Nacho Carretero, “La radicalización no fue rápida,” País, August 21, 2017, and Audiencia Nacional, Juzgado Central de Instrucción núm. 4, Diligencias Previas 60/2017, Auto of August 22, 2017, p. 6.
[ah] A female relative described Mohamed Hichamy as becoming “the most conservative” of them all, after his behavior changed some three years before the attacks. She said he refused to shake hands with women, even from his own family. A colleague at work said he “prayed a lot” but disliked to talk about his creed. In the year before the attacks, Las Ramblas attacker Younes Abouqaaoub started to follow the example of his older cousin, Mohamed Hichamy. In the same period, Mohamed Aalla and Moussa Oukabir also embraced Islamist fundamentalism. See Samia Herrazzouki, “El sospechoso del ataque de Barcelona se volvió más conservador el año pasado, según su familia,” Reuters, August 21, 2017; Colomé, Rodríguez, and Ortega-Dolz; Victor Vargas, “Younes, el joven que cambió el fútbol por el terrorismo,” Periódico, August 21, 2017; Manuel Marraco, “Los terroristas de Cataluña sospechaban que la mezquita de Ripoll estaba vigilada,” Mundo, September 2, 2017.
[ai] A second written message that claimed the attacks in Catalonia one day after they were carried out referred, for instance, to a non-existent assault on a bar and a hostage situation that never occurred. See, in this respect, Manuel Torres, “Jihadism in the Spanish Language After the Barcelona Attacks,” George Washington University, Program on Extremism, August 2017. The same mistake regarding a stormed bar was found on pages 39 and 41 of Rumiyah’s issue 13, where the car used in the Cambrils attack is referred to, incorrectly, as a truck.
[aj] In the last trip to Paris, the members of the Ripoll cell stayed at B&B Hotel Paris Malakoff, not far from Villejuif where a TATP lab was discovered on September 6, 2017. See “De l’explosif TATP découvert lors d’une opération antiterroriste à Villejuif, deux hommes interpellés,” Monde, September 6, 2017; Jean Chichizola and Christophe Cornevin, “L’officine de Villejuif aurait pu produire des kilos de TATP,” Figaro, September 7, 2017; and “Villejuif: les deux suspects voulaient confectionner une bombe en vue d’un attentat,” Parisien, September 10, 2017.
[ak] Protective bollards at the intersection where Younes Abouyaaqoub stormed into the Las Ramblas pedestrian promenade were not introduced by Barcelona’s city hall until December 11, 2017—that is, nearly four months after the van attack—following a resolution adopted by the Local Security Board (Junta Local de Seguridad). Similar protection was installed, over the prior weeks, in other popular and emblematic points of the city, such as the surroundings of the Sagrada Familia. See Alfonso L. Congostrina, “Bolardos en la Rambla cuatro meses después del atentado,” País, December 12, 2017.
[al] Mossos d’Esquadra (currently 17,000 officers) is deployed as a police force over the whole of Catalonia. CNP (with some 2,900 permanent officers in the autonomous territory) and GC (having approximately 1,900 officers in the region) are more limited in functions. See Generalitat de Catalunya, Institut d´Estadística de Catalunya, Anuario estadístico de Catalunya 2016; Javier Oms, “Interior eleva el número de policías y guardias civiles en Cataluña,” Mundo, September 9, 2017; and Luis B. García, “El contingente policial desplazado a Catalunya supera los 10.000 agentes,” Vanguardia, September 28, 2017.
[am] Mohamed Hichamy, a key cell member, personally bought 100 liters of acetone in a paint shop of Vinaroz. See Braulio García, “Cómo pudieron los terroristas de Ripoll acumular cien kilos de explosivo?” Vanity Fair (Spanish edition), September 17, 2017.
[an] According to regulation (EU) No 98/2013 of the European Parliament and of the Council of 15 January 2013 on the marketing and use of explosives precursor, vendors in Spain are required to flag suspicious sales of potential drug and explosive precursors to authorities with the client’s identity. A national law (Ley 8/2017) on the control of explosive precursors was adopted in Spain in November 2017. Further improvements concerning the practical application of such normative as well measures to control the hiring of imams, both of which are matters deriving from lessons extracted from the attacks in Barcelona and Cambrils, were announced by Spain’s minister of interior on December 27, 2017. “Zoido anuncia un paquete de iniciativas para la mejora de la seguridad y el fortalecimiento de la lucha contra el terrorismo yihadista,” Ministerio del Interior, December 27, 2017.
[ao] It should be noted that jihadi mobilization levels are proportionally lower (as compared to total Muslim population) in Spain than in some other Western European nations where Muslim populations are predominantly made up of second and further generations, such as Belgium, France, the United Kingdom, Germany, the Netherlands, Austria, Denmark, and Sweden. See Fernando Reinares, “Jihadist Mobilization, Undemocratic Salafism and Terrorist Threat in the EU,” Georgetown Security Studies Review (Special Issue, February 2017), pp. 70-76.
 Audiencia Nacional, Juzgado Central de Instrucción núm. 4, Diligencias Previas 60/2017, Auto of August 22, 2017, p. 3.
 Antonio Baquero and Guillem Sànchez, “Los terroristas de Ripoll tenían 100 kilos de explosivos para atentar en Barcelona,” Periódico, September 13, 2017.
 Diligencias Previas 60/2017, Auto of August 22, 2017, pp. 3-4.
 Manuel Cerdán, “Un mosso habló 4 minutos por teléfono con el terrorista de La Rambla dos horas antes de la matanza,” Okdiario, November 15, 2017.
 Mohammez M. Hafez, “The Alchemy of Martyrdom: Jihadi Salafism and
Debates over Suicide Bombings in the Muslim World,” Asian Journal of Social Science 38:3 (2010), especially pp. 371-372.
 Diligencias Previas 60/2017, Auto of August 22, 2017, pp. 5-6.
 Ibid., pp. 5-6.
 Ibid., p. 7.
 Ibid., p. 7.
 “Los terroristas compraron 340 litros de material para explosivos con la documentación del detenido en Castellón,” Vanguardia, September 25, 2017.
 Baquero and Sànchez.
 Diligencias Previas 60/2017, Auto of August 22, 2017, p. 6.
 Ibid., p. 6.
 For example, Stephen Burgen, “Spain terror cell was planning Sagrada Família attack, suspect tells court,” Guardian, August 22, 2017.
 Jesús García, “El terrorista herido pie ‘perdón’ y se declara ‘arrepentido,’” País, August 24, 2017.
 Observatorio Andalusí y Unión de Comunidades Islámicas de España, Estudio demográfico de la población musulmana. Explotación estadística del censo de musulmanes en España referido a fecha 31/12/2016 (Madrid: UCIDE, 2016).
 Rebeca Carranco, “Los salafistas controlan una de cada tres mezquitas en Cataluña,” País, June 18, 2016.
 Elcano Data Base on Jihadis in Spain (EDBJS). See also Estudio demográfico de la población musulmana.
 Fernando Reinares, Al Qaeda’s Revenge: The 2004 Madrid Train Bombings (New York: Columbia University Press, 2017), pp. 19-20.
 Audiencia Nacional, Sala de lo Penal, Sección primera, Sentencia 6/2007. See also Reinares, Al Qaeda’s Revenge, p. 146; “La supuesta red de Al Qaida en Cataluña podía fabricar Napalm casero,” ABC, September 13, 2003; and “El FBI ratifica su informe que decía que los detenidos en Catalunya podían hacer ‘napalm casero,’” Vanguardia, May 30, 2003.
 Reinares, Al Qaeda’s Revenge, chapter 13.
 Fernando Reinares, “The January 2008 Suicide Bomb Plot in Barcelona,” in Bruce Hoffman and Fernando Reinares eds., The Evolution of the Global Terrorist Threat: From 9/11 to Osama bin Laden’s Death (New York: Columbia University Press, 2014), pp. 334-352.
 Ibid., pp. 344-367.
 Audiencia Nacional, Sala de lo Penal, Sección Primera, Sentencia 78/2009, pp. 7-8 and 32-34.
 Fernando Reinares and Carola García-Calvo, “Los yihadistas en España: perfil sociodemográfico de condenados por actividades terroristas o muertos en acto de terrorismo suicida entre 1996 y 2012,” Madrid: Real Instituto Elcano, DT 11/2013, p. 16.
 Diligencias Previas 68/2014-15, Auto of April 10, 2015.
 Ibid., pp. 4-6.
 Ibid., pp. 8-9.
 Ministerio del Interior, Oficina de Comunicación y Relaciones Institucionales, Nota de Prensa of June 22, 2015, p. 1.
 “El cerebro de los atentados de París envió un yihadista a España,” Expansión, November 21, 2015.
 Antonio Baquero, “El Estado Islámico a una joven en Catalunya: ‘Vas a una reunión y empiezas a matar a saco,’” Periódico, March 5, 2017.
 Jean-Charles Brisard and Kévin Jackson, “The Islamic State’s External Operations and the French-Belgian Nexus,” CTC Sentinel 9:11 (2016).
 Ibid., p. 11.
 Nota de Prensa of June 22, 2015, p. 1.
 “Procesado un yihadista que volvió de Siria para cometer atentados en España,” eldiario.es, July 11, 2016.
 Guy van Vlierden, “Paris Attack Ringleader Abdelhamid Abaaoud,” CTC Sentinel 8:11 (2015), pp. 30-33; Jean-Charles Brisard, “The Paris Attacks and the Evolving Islamic State Threat to France,” CTC Sentinel (2015), pp. 5-8.
 Brisard and Jackson.
 Maria García, “Como era Younes Abouyaaqoub?” ara.cat, August 21, 2017; Jordi Pérez Colomé, Marta Rodríguez, and Patricia Ortega-Dolz, “Cómo el imán de Ripoll creó una célula yihadista,” País, August 21, 2017.
 “Uno de los terroristas cobraba 2.000 euros al mes y vivía en una vivienda de protección oficial,” ABC, August 21, 2017.
 “Omar Hichamy, educado y aparentemente integrado,” Diario Sur, August 20, 2017.
 Colomé, Rodríguez, and Dolz.
 Javier Negre, “Moussa Oukabir, de montar la fiesta de la espuma a terrorista del ISIS,” Mundo, September 5, 2017; Vanessa Lozano and Luis Rendueles, “El testamento de un yihadista,” Interviú, September 11, 2017.
 Pedro Águeda, Jose Precedo, and Marcos Pineiro, “Tres sospechosos de los atentados tienen antecedentes por delitos comunes,” eldiario.es, August 20, 2017.
 Audiencia Nacional, Juzgado Central de Instrucción núm. 4, Diligencias Previas 60/2017, Auto of August 22, 2017, p. 3.
 Pablo Muñoz and Alex Gubern, “El imán de la célula viajó en 2016 a un antiguo feudo yihadista belga,” ABC, August 21, 2017.
 Guy Van Vlierden, “Molenbeek and Beyond: The Brussels-Attacks Axis as Hotbed of Belgian Jihad,” in Arturo Varvelli, ed., Jihadist Hotbeds: Understanding Local Radicalization Processes (Milano: ISPI, 2016), p. 55.
 Quiko Alsedo and Pablo Herraiz, “El delito ‘no grave’ del imam de Ripoll: 120 kilos de droga,” Mundo, August 24, 2017.
 Enric Borràs, “Driss Oukabir: ‘Ha siguit el fill de puta de l’imam,’” ara.cat, August 28, 2017.
 Colomé, Rodríguez, and Ortega-Dolz.
 Pau Rodríguez, “Las madres de cuatro terroristas se manifiestan en Ripoll contra el atentado de Barcelona,” eldiario.es, August 19, 2017. See also, “En el nido de víboras de Ripoll: en esta casa planearon la masacre los hermanos Oukabir.”
 Lucas de la Cal, “Viaje por la tierra de origen de los terroristas,” Mundo, August 27, 2017; Sílvia Oller, “Casi todos en Ripoll hemos compartido espacio con Moussa,” Vanguardia, August 19, 2017; “El sospechoso del ataque de Barcelona se volvió más conservador el año pasado, según su familia;” “Tras la pista del comando,” Antena 3 TV, November 25, 2017, minute 30:33.
 Audiencia Nacional, Juzgado Central de Instrucción núm. 4, Diligencias Previas 60/2017, Auto of August 22, 2017, p. 4.
 Thomas Jocelyn, “Islamic State claims its ‘soldiers’ responsible for the Barcelona Attacks,” FDD’s Long War Journal, August 17, 2017.
 “Referencias a España en la propaganda yihadista,” Grupo de Estudios en Seguridad Internacional, Universidad de Granada; “El Estado Islámico reivindica el atentado en Cambrils,” Vanguardia, August 19, 2017.
 “New video message from The Islamic State: ‘The First Rain: The Raid of Barcelona. Wilayat al-Khayr,’” jihadology.net, August 23, 2017.
 Ángeles Escrivá, “La policía sigue el rastro de las españolas captadas por el IS,” Mundo, December 9, 2014; Martín Mucha and Toñi Caravaca, “Y Tomasa se fue a la guerra (con sus seis hijos),” Mundo, December 22, 2014; “El terrorista de Daesh nacido en Córdoba que amenaza a España con nuevos ataques,” ABC, August 24, 2017; “Ahram Pérez, el yihadista que amenaza a España en el último vídeo del Daesh,” Público, August 24, 2017.
 “New video message from The Islamic State.”
 “Referencias a España en la propaganda yihadista.”
 Rumiyah, Issue 13, September 2017, p. 5.
 Jesús García, “Los viajes de la célula antes del ataque: Francia, Bélgica, Suiza y Marruecos,” País, August 23, 2017; Jean Chichizol, “Les auteurs des attentats de Catalogne se sont rendus au moins trois fois en France,” Figaro, September 9, 2017.
 “La policía investiga un viaje a Zúrich de dos de los terroristas en diciembre,” Vanguardia, August 25, 2017; García, “Los viajes de la célula antes del ataque: Francia, Bélgica, Suiza y Marruecos.”
 Diligencias Previas 60/2017, Auto of August 22, 2017, p. 7.
 See Lucas de la Cal, “Los nueve días de Driss Oukabir en Marruecos,” Mundo, August 28, 2017. See also Lucas de la Cal, “Viaje por la tierra de origen de los terroristas,” Mundo, August 27, 2017.
 Luis Rendueles and Vanesa Lozano, “Atentados en Barcelona. Los terroristas dejaron un vídeo,” Interviú 2173, December 2017, pp. 10-11.
 Angélique Négroni, “Terrorisme: un mur à 20 millions d’euros pour protéger la tour Eiffel,” Figaro, September 19, 2017.
 See Rendueles and Lozano, “Atentados en Barcelona.”
 Enric Hernàndez, “Los Mossos recibieron la alerta de atentado en Barcelona de la CIA el 25 de mayo,” Periódico, August 31, 2017; Enric Hernàndez, “EEUU confirma que alertó a los Mossos,” Periódico, September 1, 2017.
 José M. Olmo, “La célula del atentado compró las bombonas con dinero de la venta de oro y joyas,” Confidencial, August 21, 2017.
 Alejandro Requeijo and Daniel Montero, “Said, el tendero que dejó su furgoneta y documentación al yihadista de la Rambla,” Español, September 22, 2017.
 Antonio Baquero, Guillem Sànchez, and Ángeles Vázquez, “Los terroristas no iban a suicidarse y planeaban varios días de atentados en Barcelona,” Periódico, September 17, 2017.
 “Andreu delimita el papel de Mossos, Policía y Guardia Civil y deja la coordinación en manos del CITCO,” Europa Press, August, 24, 2017; “El juez centraliza la investigación entre las dudas por el seguimiento al imán,” Agencia EFE, August 24, 2017.
 Gobierno de España, Ministerio del Interior, Nivel de Alerta Antiterrorista (NAA).
 Fernando Reinares and Carola García-Calvo, “Actividad yihadista en España, 2013-2017: de la Operación Cesto en Ceuta a los atentados en Cataluña,” Madrid: Real Instituto Elcano, DT 13/2017.
 Julien Toyer, “Belgium gave tip to Catalan police about imam before attack – source,” Reuters, August 24, 2017; Patricia Ortega and Álvaro Sánchez, “Los Mossos fueron informados por los belgas de las sospechas sobre el imán de Ripoll,” País, August 23, 2017.
 Patricia Ortega, “El CNI admite contactos con el cerebro de los atentados de Barcelona,” País, November 17, 2017.
 “El imán de Ripoll tenía una orden de expulsión de España,” Vanguardia, August 22, 2017; “El juez anuló la orden de expulsión del imán de Ripoll por su evidente arraigo laboral y esfuerzos para integrarse,” Vanguardia, August 23, 2017.