The criminal proceedings against Quebec City's mosque shooter provided a glimpse into how police use computers to extract information about a suspect, even if that data has been erased.

The man who murdered six Muslim men in a Quebec City mosque in January 2017 had been suffering with mental illness for years and wanted to kill, a psychologist who evaluated the gunman said in court on Monday, April 23, 2018.

The man who murdered six Muslim men in 2017 told a social worker several months after the killings that he wished there had been more victims, evidence tabled in court on Monday, April 16, 2018, indicated.

The gunman who killed six men as they prayed in Quebec City in 2017 told investigators he went to the mosque because he wanted to protect his family from terrorist attacks, according to a video of his interrogation tabled in court on Friday, April 13, 2018.

Shortly after Alexandre Bissonnette opened fire in a Quebec City mosque in 2017 and murdered six men, he called 911 and told the operator he was going to shoot himself, according to the audio recording tabled as evidence Thursday, April 12, 2018.

Footage captured by surveillance cameras during the 2017 shooting at a Quebec City mosque shows Alexandre Bissonnette calmly murdering men lying on the carpet who were already injured by his bullets.

The man who killed six Muslims in a Quebec City mosque last year as they attended prayer sought forgiveness Wednesday for his acts and said it was "as though I was battling a demon that finished by winning out."