The terrorist who killed 14 people and injured over 100 in August's van attack on Barcelona's Ramblas told a woman he did not know what had happened as he walked calmly away from the carnage, according to newly released video.
Younes Abouyaaqoub was making his way slowly through the La Boqueria market when he was caught on camera by a woman who asked him if he knew what had happened.
"I don't know, that's happening over there," he replied casually, pointing over his shoulder.
The terrorist, who later hijacked a car and stabbed its occupant to death on the outskirts of the city, appeared relaxed, betraying nothing of the violence he had just perpetrated.
Abouyaaqoub hijacked the car as owner Pau Perez was parking and stabbed him to death, putting him in the backseat before crashing through a police checkpoint on the city's Avenida Diagonal, injuring one officer. The car was later found abandoned with Perez's body inside in Sant Just Desvern, a Barcelona suburb.
Abouyaaqoub's flight triggered a four day manhunt across Catalonia, which ended when he was shot dead by police on a remote country lane near the cava-producing town of Sant Sadurni, some 30 miles outside the city.
Police said at the time he had walked all the way from Barcelona, sleeping in barns, before being spotted by local residents who reported a suspicious person around the town.
He had changed clothes and was wearing a fake explosive belt, shouting "Allahu Akhbar" as he was confronted by agents who quickly opened fire.
The video was released just after a major terror alert once again jangled nerves in Barcelona.
On Tuesday night, several city blocks around the iconic Sagrada Familia cathedral were evacuated by police as they investigated a suspicious van.
Helicopters buzzed overhead as a Tedax specialist explosives unit was deployed to check the vehicle, in an incident which was later confirmed to be a false alarm.
Police have boosted security across the city, in particular around landmarks such as the Sagrada Familia.
The Antoni Gaudi cathedral had previously been eyed as a target by the cell which carried out the August 17 attack in Barcelona and a later assault in the seaside town of Cambrils which left one dead.
However they were forced to change their plans after explosive material destined for the plot was destroyed in an accidental blast at their safehouse on the night of August 16.
The Catalan police force said had been carrying out checks around the Sagrada Familia on Tuesday when they spotted the suspicious vehicle.
Local media reported that the alert had been prompted by a warning received by Spanish intelligence that a group of jihadists were planning to imminently launch an attack in Spain or France.