Yesterday afternoon, after a considerable manhunt which had officially gone Europe-wide, Catalan police shot dead Younes Abouyaaqoub. He was the twelfth and until then only unaccounted for member of the terrorist cell responsible for the deadly attacks in Barcelona and Cambrils last week.

The 22-year-old was suspected to be the driver responsible for mowing down pedestrians on Las Ramblas in the heart of Barcelona, resulting in 130 injuries and 13 deaths. According to reports further harm would have been caused had the airbags inside the van not been activated by the collisions.

The identities known so far paint a typical picture of happy visits to Barcelona from all over the world. They included: 7 year old Julian Cadman who had dual British and Australian nationality and who tragically became separated from his mother when the van struck; Jared Tucker (42) from the United States who was in Barcelona with his wife Heidi Nunes to celebrate their first wedding anniversary; Bruno Gulotta (35) from Italy who died in front of his wife and two small children. Each victim was in Barcelona for happy reasons which are so sharply juxtaposed to the way in which they died.

Younes Abouyaaqoub was suspected to have fled to France or perhaps further afield. He was, however, tracked down hiding in a vineyard near the small town of Subirats only 30 miles west of Barcelona, thanks to a civilian tip-off – much like five of his counterparts who were shot dead by police in Cambrils four days earlier, Abouyaaqoub was wearing what later turned out to be a fake suicide belt when confronted. These men, or technically boys in many cases, opted for martyrdom over injury and arrest.

Retracing the steps back to the attack which shook the Catalan Capital, briefly transforming it into an unrecognisable ghost-town, it is clear that the past few days have been an exercise in joining the dots for Catalan and Spanish authorities. A previously unexplained large explosion, which toppled a villa in the coastal town of Alcanar at the very south of Catalonia, suddenly became extremely relevant. Not only was it where the imam Abdelbaki Es Satty and suspected chief manipulator of the group seems to have accidentally blown himself up along with another member of the 12 strong cell, the sheer amount of explosives (there were more than 100 gas canisters stored there) mistakenly detonated at Alcanar reveals plans of a much greater and a much deadlier scope.

Another piece of the jigsaw puzzle involved the very unfortunate Pau Pérez who was found dead due to a stab wound in his Ford Focus car. Police were able to link the death of Mr Pérez to Younes Abouyaaqoub’s astonishing escape from the scene of the carnage he caused with the van on Las Ramblas, making him the 15th victim of the attacks. Footage from CCTV camera clearly shows Abouyaaqoub exiting Las Ramblas via the famous food market of La Boqueria, putting on sunglasses and walking, instead of running, to blend in. It seems that he then crossed the city on foot, the whole way to the University Zone where he had his violent encounter with Mr Pérez whose car he tried to use to get further away from Barcelona.

The remaining four members of the cell, Driss Oukabir, Sahal el Karib, Mohammed Aalla and Mohamed Houli, who had been held in custody in Ripoll, have now been transferred to Madrid where they today faced a judge in a special terrorism tribunal in Spain’s National Court.

Ripoll, the sleepy Pyrennean town of 11,000 inhabitants in Northern Catalonia served as the unlikely backdrop for this hub of radicalisation. The residents are in a state of shock that such a sizeable terrorist cell boasting 4 sets of brothers could have formed in their town unnoticed by them, and the authorities. Local young people who attended school with Abouyaaqoub say he was a good friend and was so integrated that he passed for Catalan. Meanwhile the Mayor of Ripoll, Jordi Munell, seems truly at a loss to understand how this came about: “We don’t understand. These boys weren’t marginalised. They were neighbours, teammates, supermarket workers, schoolfriends.”

Shock is also reverberating amongst the families of the young men involved, who took part in a march of solidarity against terrorism in the town’s main square on Saturday. For the most part they insist many of the members of the cell were not devout muslims until perhaps very recently.  According to Ali Yassiné, president of Ripoll’s Annur Islamic Community, “They rarely attended … I doubt if any of them could tell you the colour of the carpet in the mosque.”

Hechami Gasi, the father of brothers Mohamed and Omar Hychami anguished, “I don’t know how they could have done so much wrong, so much harm… The imam must have put these ideas in their heads. They were good boys.”

There is a clear concensus that the boys’ paths changed with the arrival of Es Satty, who had been in Ripoll for some 2 years. He is in fact the only member of the group who had previously been known to authorities, having been jailed in Valencia in 2010 for smuggling cannabis. It was during his time there that he became acquainted with Rachid Aglif who was in prison for his part in the 2004 Madrid bombings which killed 192 people.

Es Satty then cropped up in a report made by police after attempts to recruit men to fight with ISIS in Iraq from the Barcelona area. Then there are the connections with both Belgium, where Es Satty appears to have lived and travelled to often, and France; it has just been confirmed by the French Interior Minister, Gérard Collomb, that some of the group, perhaps including Es Satty made a quick trip by car to Paris days before the atrocities were carried out in Catalunya. The reasons for this trip are currently under investigation.

Members of the Generalitat, the Government of Catalonia, have been steadfast in their insistence that the most important task ahead is understanding the process of radicalisation undergone by these young men. As was stressed by the Catalan Foreign Affairs Minister, Raul Romeva, in an interview with Channel 4 news, reacting with fear by building fences around iconic sites like Las Ramblas is simply not a solution.

This openness to understand without fear is something which could be said to be intrinsic in the spirit of Barcelona itself, which has long been famous for embracing strangers from all backgrounds and origins, without questions. Her people, Muslim and non-Muslim, have carried that spirit onto the streets in the past few days, chanting ‘no tinc por‘ (I am not afraid), showing their solidarity with the victims with flowers, letters and candles, and their opposition to those who seek to sabotage Barcelona’s boundless joy.