08/29/2016 04:05 EDT | Updated 08/29/2016 05:59 EDT

Toronto Crossbow Attack Autopsy Results Released By Police

TORONTO — Police have released the cause of death of three people killed in a bloody attack involving a crossbow in east Toronto last week.

Toronto police Det. Sgt. Mike Carbone says a woman found in a stand-alone garage on Thursday died from ligature strangulation, a man found in the same garage died from a crossbow bolt stab wound to the neck and a man found in the driveway died from a single arrowhead stab wound to the neck.

However, he would not say whether the bolt and arrowhead were shot or used as handheld weapons.

"I can say that a crossbow was seized from the scene," he said Monday. "Because this currently is before the courts, I'm not going to distinguish between the two methods of how these two individuals were murdered."

brett ryan crossbow

Brett Ryan is shown in this image from Facebook. (Photo: The Canadian Press Handout/Facebook)

Brett Ryan, 35, of Toronto is charged with three counts of first-degree murder in the slaying.

Officers called to a home on reports of a stabbing found the lifeless bodies of two men and a woman in the garage and driveway with a crossbow lying nearby.

Police say a witness was also taken to hospital and treated, though no charges have been laid in connection with that person at this time.

Carbone says police want to talk to anyone who was in contact with Ryan between 7:30 a.m. and 11:30 a.m. on Thursday.

"The investigation was very, very unusual."

Investigators have released few details about the killings or what might have motivated them.

The relationship between the accused and the four victims has not been released, and the names of the victims cannot be reported due to a court-ordered publication ban.

"The investigation was very, very unusual," Carbone said. "When we became involved, the identity of the three individuals that had been murdered was still not confirmed. There was a publication ban placed at that time obviously until we had completed our jobs. That may change in the near future."

Police also examined a waterfront apartment associated with Ryan last Thursday but found there was no threat to the public, Carbone said.

toronto crossbow attack

Police and paramedics stand in the driveway of a house in Scarborough, Ont., on Thursday after three people were killed in a crossbow attack. (Photo: Pascal Marchand/Canadian Press)

Ryan is due in court Friday.

He was charged in 2008 with a total of 29 counts of robbery, intent to commit a crime while disguised, and a weapons offence.

In January 2009, he pleaded guilty to eight counts each of robbery and intent to commit an indictable offence while disguised. The remaining counts were withdrawn. He was sentenced to 45 months in prison — less seven months for pre-trial custody. The court also imposed a lifetime weapons ban.

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