The man accused of killing four members of a Muslim family in an alleged act of terrorism told a jury Friday that his mind was “corrupted” by online conspiracy theories and that he eventually developed a desire to engage in an act of violence.

In his second day of testimony, Nathaniel Veltman told court that as his mental state deteriorated during the pandemic, he began consuming more online content that included unfounded conspiracies about COVID-19 and Muslims.

“This content started to warp my view of the world,” he said. “It was starting to cause this seething anger.”

The 22-year-old said he was always drawn to “whatever was fringe and conspiracy related,” but didn't initially identify with a lot of the content he was viewing.

He said he tried to block some of the websites he was visiting with an app originally intended to block access to pornography and even removed or destroyed some of his electronic devices, but he always went back to the disturbing content. He said he became “addicted” to it.

“Slowly I became desensitized to the offensive material,” he testified.

On the stand in the Windsor, Ont., courtroom where the trial is taking place, Veltman has been detailing what he described as a process of mental decline that started when he began spending a lot of time on the internet in the early months of the pandemic.

As time went on and after two aborted attempts to end his life in March 2021, Veltman said things changed.

“I no longer tried to avoid the things that I knew triggered something in me. I felt I had nothing to lose,” he said.

Veltman said his suicidal ideation “suddenly morphed into something else.”

“(I had) desire to engage in an act of violence and avenge these things that I was seeing,” he said, referring to extreme-right websites carrying baseless conspiracy theories about Muslims.

Veltman is accused of deliberately hitting the Afzaal family with his truck in June 2021 while they were out for a walk in London, Ont.

Salman Afzaal, 46; his 44-year-old wife, Madiha Salman; their 15-year-old daughter, Yumna; and her 74-year-old grandmother, Talat Afzaal, were killed in the attack, while the couple's nine-year-old son was seriously hurt but survived.

Veltman has pleaded not guilty to four counts of first-degree murder and one count of attempted murder.

Jurors have previously seen video of Veltman telling a detective that his attack had been motivated by white nationalist beliefs. The Crown has argued that Veltman planned an attack for three months and that his actions amount to terrorism.

Veltman also told the jury Friday about two instances in which he took psilocybin, or magic mushrooms, in attempts to cope.

He said he took a “large” amount of magic mushrooms in April 2020 that made him hear “demonic voices” and writhe on the floor.

“I forgot who I was, I forgot where I lived, I forgot what planet I was on … it was like a complete memory wipe,” he testified.

Veltman said he also consumed magic mushrooms on June 5, 2021, a day after his grandmother had died and he had gone to see her body.

Veltman said he was distraught over the death of the woman he considered his “substitute” mother and pressured a friend to give him more of the drugs than the friend thought was safe for him to consume. He said he was very disturbed at the time and wanted to “escape” by taking psilocybin.

The attack on the Afzaal family occurred on June 6, 2021.

Veltman told the jury on Thursday that he had a “fundamentalist” Christian upbringing marked by regular punishments from his mother, which included spankings. He said he was homeschooled until Grade 11 and the isolation from the wider community made him socially awkward and drawn to “outcasts” and “bad” crowds later in life.

Veltman's case is the first where Canada's terrorism laws are being put before a jury in a first-degree murder trial.

This report by The Canadian Press was first published Oct. 13, 2023.