At 4.50pm on Thursday August 17, Younes Abouyaaqoub started his murderous rampage by driving a white Fiat rental van onto the pedestrianised central portion of Barcelona’s famous La Rambla, accessing the northern end of the avenue via Pelai street. After weaving left and right for 500 metres, killing 13 people and injuring scores more, the airbag in the van’s driver seat activated itself, stopping the vehicle in its tracks.

Abouyaaqoub got out of the van and, was apparently filmed on CCTV images walking calmly away through the city’s emblematic La Boqueria food market wearing a blue and white polo shirt, dark trousers, trainers and a pair of sunglasses.

According to Catalonia’s police chief, Major Josep Lluis Trapero, the 22-year-old Moroccan man then “walked and ran” six kilometres across the city in a westerly direction amidst the din of emergency sirens as ambulances transported the dead and injured to hospitals and the police mounted what they dubbed “Operation Cage” aimed at preventing terrorist suspects from escaping the city centre.

At around 6.30pm, an hour and a half after the slaughter on La Rambla, Abouyaaqoub then came across Pau Pérez, a 34-year-old aid worker who was in his car in Barcelona’s University Zone, just off the city’s major El Diagonal traffic artery. According to the police’s version of events, Abouyaaqoub stabbed Pérez several times and took the wheel of his white Ford Focus, shoving his victim’s body into the back of the vehicle.

Abouyaaqoub then drove through a police checkpoint on at the western end of El Diagonal, breaking an officer’s leg. Police fired shots but the car was not stopped.

The Ford Focus was later found abandoned some two miles further west in the Sant Just Desvern area, on the outskirts of Barcelona, with Mr Pérez’s dead body inside. The police initially thought that the incident was not connected to the van attack on La Rambla, having identified the owner of the car as an unlikely terrorist suspect. When the autopsy revealed that Mr Pérez had been stabbed and not hit by a police bullet, investigators began to search for a link to the attacks.

As, over the weekend, investigators untangled the web of the terrorist cell that had formed among young men of Moroccan origins in the small Pyrenean town of Ripoll, Abouyaaqoub was increasingly considered chief suspect of the van attack. Nothing is yet known about what Abouyaaqoub did during that time, except for the fact that he managed to travel some 25 miles west from the place in which he ditched the Ford Focus, possibly across mountainous terrain to the area in which police caught up with him at around 4.30pm on Monday afternoon.

La Vanguardia has reported that Abouyaaqoub was located by the police after a woman in the Subirats area called in after seeing a man who looked like the chief suspect in the Barcelona van attack outside her home. The woman reportedly shouted at him and asked him what he was doing there, causing the suspect to run away into a vineyard.

According to other unconfirmed reports, the woman said that Abouyaqoub had been whistling, as if trying to communicate with someone he had arranged to meet amongst nearby buildings.