Neighbours in the East York building where a six-year-old boy was killed by his father in an apparent murder-suicide on Monday night say they were alerted to the crime by the screams of the boy’s mother.

Police say they were called to a residence at 20 Gamble Avenue, off of Broadview Avenue and north of Cosburn Avenue, on Monday night just after 7.

They arrived to find a father and son both without vital signs. Both were pronounced dead at the scene. Police said the boy suffered unspecified trauma.

The boy’s mother is cooperating with the investigation, authorities said.

The two deceased have been identified as 58-year-old Zlatan Cico and Simon Cico, 6, of Toronto.

A neighbor, Pearse Vujcic, told CTV News Toronto that he and two other neighbours heard the voice of the boy’s mother, screaming, from the unit belonging to the boy’s father.

“We went inside and saw everything,” Vujcic said.

He said they saw a note inside, but he would not comment on what it said.

Neighbours said the Simon’s parents separated years ago, but that the boy would visit his father often.

Investigators say they are not seeking any suspects. Douglas-Cook said a post-mortem examination on the boy’s body may be complete by Wednesday.

Vujcic said he noticed Zlatan appeared “down from time to time” but he said he was angry at himself for not doing anything to help.

“For the rest of my life I'm going to blame myself I didn't notice he was suicidal.”

A friend of Zlatan told CTV News Toronto in an email that people should know he was a “good and intelligent man but deeply ill and had nobody to notice that, he was lonely.”