TORONTO -- A man who went on a shooting rampage in Toronto's Greektown last summer had a fascination with death and violence, a long history of mental-health issues and repeatedly harmed himself, police said Friday.

But even after a nearly year-long probe into Faisal Hussain's shooting spree on a bustling stretch of Danforth Avenue, investigators said they were unable to pinpoint a motive for the 29-year-old who killed himself after the attack.

Hussain had no criminal record, there was no evidence he had been radicalized, and police found no affiliation with hate or terror groups.

"The one question the family and the public wanted to know is why," Chief Mark Saunders said as he detailed the findings of the probe. "Although we collected all of the evidence that was available to us for this crime, a crime where the shooter died at the scene, we may never know the answer to why."

Hussain killed 10-year-old Julianna Kozis and 18-year-old Reese Fallon and injured 13 others on July 22, 2018.

Details of the police investigation, contained in a report made public Friday, revealed a portrait of a deeply troubled individual who struggled for years with his mental health.

Issues emerged when he was in Grade 4, in 1998, and had difficulty functioning in the classroom. An assessment concluded he had "secondary behavioural issues" and intellectual deficiencies, and recommended more resources to help manage his behaviour, the police report said.

The Toronto District School Board provided social workers and learning plans, and Hussain continued with his academics.

Through Grades 4 to 6, school staff reported Hussain spoke "enthusiastically about gangs, weapons and being tough." He was repeatedly referred to the school board's social work department over concerns about his mental health and the safety of students.

"He was not functioning well in the classroom and appeared to have a fascination with killing, violence and death," the police report said.

Hussain told school social workers he did not have friends or a girlfriend and did not talk to his parents. A risk assessment found he was a "medium to high risk for violence," the police report said.

In May 2010 -- the year he graduated from high school at age 21 -- Hussain went to hospital after cutting his face during class. Three weeks later he cut his face again, this time with a pencil sharpener, the police report said.

His family believed his behaviour "was an effort to garner attention," police noted.

Two weeks later, police brought Hussain to hospital after he took a steak knife from a teacher, said he was the Joker and refused to return the blade. He was diagnosed with antisocial personality disorder. He told the doctor he had a history of violence, including torturing and killing animals.

Hussain's problems continued after he left school.

On Feb. 15, 2012, he called police from a park saying he was going to kill himself with a knife, the investigation report said. Police found him with the knife and cuts to his face. He told officers he had been depressed for years.

Notes from his hospital visit show Hussain said he had been cutting himself as "a form of relief."

In 2014, Hussain told a doctor he no longer wanted to be treated, the police report said.

On the day of attack on the Danforth, Hussain showed up for work an hour late, which wasn't unusual. He clocked out about three hours later, around 3 p.m., and went home to the apartment where he lived with his parents.

His family said they spoke to Hussain that day about his future and "that he should find a wife." The family told police the conversation upset Hussain.

Overall, however, there was nothing unusual about Hussain that day, said Det. Sgt. Terry Browne.

"There is nothing that anyone relayed to us that suggests to us that he was in crisis on that day," Browne said.

Shortly after 9 p.m. Hussain left home and walked to Greektown where he shot at people on the street, on patios and in restaurants.

After the attack, police found a cache of ammunition in his home along with heroin and other drugs, but no guns. The gun Hussain used in the attack was stolen from a Saskatchewan gun shop in 2016, but it's unclear how it came into his possession, police said.

On his phone, police found a full copy of the Diagnostic and Statistical Manual of Mental Disorder, Mein Kampf and a story about Elliot Rodger, a man who hated women and killed six and injured 14 in California in 2014.

Police also found web searches and news articles on Hussain's phone about Alek Minassian, the man alleged to have driven a van down a busy Toronto street and killing 10 people in April 2018. Police did not comment further on that finding.