Joakim Robin Berggren was detained after the chase on Tuesday, which had intially sparked fears of an attempted attack similar to those that took place last year in the French city of Nice and Berlin.
But it soon emerged that this was no planned attack, with the 32-year-old Swede likely intoxicated.
On Wednesday, Jordi Jane, director of the regional interior department of Catalonia where Barcelona is located, told reporters that Berggren had spent “the night partying hard.”
“He spent a lot of money and did things that very likely gave him constant euphoria for many hours,” he added, implying that he had taken drugs.
Come morning, witnesses say the Swede had shown “erratic behaviour” and had tried to rob several vehicles before managing to steal the small butane truck, laden with 200 gas bottles.
After being chased by police for close to three kilometres (2 miles) and losing half of the bottles, the truck finally stopped after having turned down the wrong way of a ring road, hit several cars and finally a wall.
Police also fired on the truck in a bid to stop it in its tracks.
Three people were slightly injured, including a Brazilian woman who was hit by a falling gas bottle during the chase.
Jane said that the driver, who was not hurt, had been detained and charged with “stealing a vehicle, attacking police agents, reckless driving, causing injury and damage.”
In the coming days, he will be questioned by a judge who will either confirm or reject the police charges.
Jane said the incident was no terror attack, reiterating what Interior Minister Juan Ignacio Zoido said Tuesday.
He added it was “an incident that hadn't been planned, it was improvised.”
Berggren, who is now in hospital, arrived in Barcelona on Monday from Moscow, where he had travelled to from Copenhagen.
Court documents in Sweden seen by AFP revealed he had served prison time before 2012, though why he was jailed is not known as these details are erased from criminal records after five years.
He then ended up back in court twice for driving under the influence of drugs, taking drugs and for carrying a banned weapon – in this case brass knuckles – and was fined for each offence.
By Daniel Bosque / AFP