The week before he killed six Muslims, Alexandre Bissonnette returned home to live with his parents where, "anxious and unstable," he declared his support for Donald Trump's immigration policies.

Bissonnette, 28, admitted to the attack on Wednesday, pleading guilty to killing six Muslim men, and critically injuring five others.

Bissonnette initially pleaded not guilty during a pretrial hearing earlier this week, and Crown prosecutors had prepared a large body of evidence for trial, which was to begin next month.

Some of that evidence can now be made public, and includes sections from a search warrant application filed by Quebec provincial police a week after the shooting.

Though parts of the application are redacted, it nevertheless offers insight into Bissonnette's state of mind just before, and after, the deadly attack on the mosque.

In a summary of an RCMP interview with the suspect's mother, Manon Marchand, the affidavit notes: "He would agree with the statements of [U.S. President] Donald Trump to the effect that all immigration should be blocked."

It is unclear if this referred to a specific policy, but two days before the shooting Trump signed an executive order that barred citizens from seven Muslim-majority countries from entering the U.S.

The order also temporarily suspended the admission of refugees. It was popularly referred to as a "travel ban" or an "immigrant ban."

Flowers lay at the men's entrance of the Quebec mosque on February 1, 2017 in Quebec City. (Jacques Boissinot/Canadian Press)

'Anxious and unstable'

Last year, one of Bissonnette's friends told CBC News that the day before the shooting they discussed the travel ban in a private Facebook exchange.

​"He told me he just wanted white immigration to Canada and Quebec, exclusively," said Martin Robin, who knew Bissonnette from Laval University.

"He told me that in the long run, this non-white, non-European immigration may perhaps lead to the marginalization of whites. That's pretty much what struck me and what keeps popping up in my mind."

On Wednesday, after pleading guilty, Bissonnette read a statement in which he said: "I am not a terrorist, nor an Islamophobe, rather a person who was carried away by fear, negative thoughts and a horrible form of despair."

According to the affidavit, Bissonnette's mother told police her son was very "anxious and unstable" in the week before the shooting.

Though he shared an apartment with his twin brother not far from the mosque he attacked, Bissonnette was staying with his parents at the time.

His doctor had recently given him a new prescription, for the drug apo-paroxetine, which is commonly used to treat depression and anxiety, Marchand told police.

In the days after the shooting, people left flowers and candles under the police tape surrounding the perimeter of the Quebec Islamic Cultural Centre. (Christinne Muschi/Reuters)

Call from highway

On the night of Jan. 29, 2017, Bissonnette had dinner with his parents, according to sections of the warrant application that were previously made public.

Afterward he borrowed his father's Mitsubushi RVR and told his mother he was heading to the Castors de Charlesbourg, a gun club where he was a member and an accredited handgun shooter.

Crown prosecutors intended to tell the jury that not long before 8 p.m. ET, Bissonnette stopped at a corner store and bought a lemon-flavoured alcoholic cooler.

He then drove to the Quebec Islamic Cultural Centre, and started shooting as he walked toward the front door.

Bissonnette's parents leaving the Quebec City courthouse Wednesday, after their son's guilty plea. (Radio-Canada)

At 8:11 p.m. Bissonnette placed a call to 911. The information released Wednesday reveals he was about 16 kilometres away from the mosque at the time, parked on the Félix Leclerc Highway, with the Mitsubushi's flashers on.

The 911 call lasted 50 minutes. Bissonnette identified himself as the shooter and told the dispatcher he wanted to turn himself in, according to the affidavit. He was crying and mentioned being able to see a bridge.

"He says he wants to go walk in the woods and fire a bullet in his head. He says he will cooperate 100 per cent. He is tired and wants the police to intervene," the summary of the call reads.

A tactical unit eventually arrived on the scene. The affidavit indicates Bissonnette was taken into custody and read his rights at 9:11 p.m.