Family of the gunman who killed two and left 13 injured after opening fire in Toronto over the weekend say that he suffered from psychosis and depression prior to the shooting, but that they never thought he was capable of indiscriminate murder.

The 29-year-old gunman died Sunday after opening fire on one of the city’s busiest stretches of road in the Greektown neighbourhood, though it is not yet clear if his death was self-inflicted or the result of a shoot out with the two police officers who responded to the violence.

“Our son had severe mental health challenges, struggling with psychosis and depression his entire life,” the family of the gunman, identified by officials as Faisal Hussain, said in a statement.

The family included condolences to the families for their son’s “horrific actions”, and said they were “utterly devastated” by the events.

“While we did our best to seek help for him throughout his life of struggle and pain, we could never imagine that this would be his devastating and destructive end,” the statement said. “Our hearts are in pieces for the victims and for our city as we all come to grips with this terrible tragedy. We will mourn those who were lost for the rest of our lives”.

The gunman killed 18-year-old Reese Fallon, a recent high school graduate who was set to begin university this fall. The other fatality, a 10-year-old girl, was not immediately identified by name.

Toronto shooting: gun attack in Greektown Show all 15 1 /15 Toronto shooting: gun attack in Greektown Toronto shooting: gun attack in Greektown A man joins a vigil for the victims of a shooting the evening before, in Toronto The Canadian Press via AP Toronto shooting: gun attack in Greektown Police investigate a car with a bullet hole AP Toronto shooting: gun attack in Greektown Friends of 18-year-old shooting victim Reese Fallon leave candles on pictures of Fallon at a makeshift memorial AP Toronto shooting: gun attack in Greektown A crime scene clean up crew scrubs the side walks AFP/Getty Images Toronto shooting: gun attack in Greektown Desirae Shapiro, 19, left, and her mother, Gina Shapiro, friends of 18-year-old Danforth shooting victim Reese Fallon, react after visiting a makeshift memorial AP Toronto shooting: gun attack in Greektown Police officers investigate a mass shooting on Danforth Avenue REUTERS Toronto shooting: gun attack in Greektown Police are seen near the scene the shooting REUTERS Toronto shooting: gun attack in Greektown A friend of a victim who died in the shooting tries to go to the crime scene AFP/Getty Images Toronto shooting: gun attack in Greektown A police officer looks for evidence under a car REUTERS Toronto shooting: gun attack in Greektown People leave an area taped off by the police near the scene REUTERS Toronto shooting: gun attack in Greektown People leave personal messages on a building under renovation, remembering the victims of Sunday's shooting on and near Danforth Avenue AP Toronto shooting: gun attack in Greektown Toronto Police officers work on Danforth St AFP/Getty Images Toronto shooting: gun attack in Greektown Residents of the Danforth area leave flowers and light candles for the victims at the scene AFP/Getty Images Toronto shooting: gun attack in Greektown Toronto mayor John Tory speaks to police officers at the scene AFP/Getty Images Toronto shooting: gun attack in Greektown Toronto Police investigate the scene of the shooting AFP/Getty Images

The injured victims range in age from 10 to 59.

Ms Fallon’s family, in a statement, said that they were devastated by the loss of their daughter, a former volunteer for Canada’s Liberal Party who had her whole life ahead of her.

The Sunday shooting has once again shaken the city, where just three months ago a man drove a van through a city sidewalk, killing 10 people and injuring dozens more.

“It’s almost inconceivable that these things can happen,” John Tory, Toronto’s mayor, said. “We were so used to living in a city where these things didn’t happen and as we saw them going on in the world around us [we] thought they couldn’t happen here.

The city has struggled with elevated levels of gun violence recently, and Mr Tory has questioned why guns are allowed in his city at all.

Individuals hoping to own a gun must apply for a license, pass a firearms safety test, and pass a background check before receiving approval.

Then, firearm owners must keep their guns locked and unloaded, and the weapons are not supposed to leave an individual’s home, unless the owner has a special permit.