Luka Rocco Magnotta's father described his son Friday as a "very mixed-up" child with no friends and suggested that he was abused by his mother's family.
The man, whose name is subject to a publication ban, testified at Magnotta's first-degree murder trial that his son's given names at birth included Clinton and Kirk – in reference to tough-guy actors Clint Eastwood and Kirk Douglas.
He said Magnotta is the oldest of three children and that he and his brother bore the brunt of the abuse from their mother's family.
"They were very mixed-up kids in all ways and they still are," said the witness, who described himself as schizophrenic.
The father said Magnotta was home-schooled until he was in Grade 6 or 7 but was poorly taught by his mother.
"She was very clingy, she wanted to have total control over them," he said of the woman. "In my opinion, she didn't do a very good job.
"He [Magnotta] had no friends, he was being home-schooled, no interaction with anyone … neither son did."
When Magnotta was finally enrolled in school, he was mistreated by other kids, said the 50-year-old Ontario man.
"I am here to help my son," said the father, who was accompanied by a support person as he spoke while seated on a cafeteria chair.
Magnotta, 32, is charged in the slaying and dismemberment of Jun Lin in May, 2012, in Montreal before he fled to Paris and then Berlin.
He has admitted to killing the Chinese engineering student, but has pleaded not guilty by way of mental disorder.
The father acknowledged having mental problems, which became apparent to him in the mid-1990s when his marriage ended. It was after he stopped drinking that he realized the extent of his psychological issues.
"I heard voices, I felt like suicide, I felt angry."
The man is still taking several medications to this day, including antidepressants and anti-psychotic pills.
He described his son as animal lover who had a particular affinity for Duke, a mix of husky and German shepherd.
Magnotta faces four charges in addition to premeditated murder: criminally harassing Prime Minister Stephen Harper and other members of Parliament; mailing obscene and indecent material; committing an indignity to a body; and publishing obscene materials.