Toronto police have revealed that a woman killed in a triple homicide last Thursday died of strangulation, while two men died of crossbow bolt and arrow injuries to the neck.

The bodies of the woman and one man were found in a garage and the body of the other man was found on the driveway in a Scarborough neighbourhood, police said on Monday.

Det. Sgt. Mike Carbone shared results from autopsies carried out Saturday and revealed the cause of death for each homicide:

The woman found in the garage died of ligature strangulation.

The man found in the garage died of a crossbow bolt stab wound to the neck.

The man found on the driveway died of a single arrowhead stab wound to the neck.

Brett Ryan, 35, was charged with three counts of first-degree murder on Friday. Police confirmed on Thursday that they had a suspect in custody who also had injuries.

A source with knowledge of the investigation said it's believed all three deceased are related to each other, CBC News learned last week.

Toronto police and paramedics were sent to a Scarborough neighbourhood where three people were found dead last Thursday. (Pascal Marchand)

Officers initially responded to a report of a stabbing at around 1 p.m. ET Thursday on Lawndale Road near Markham Road and Eglinton Avenue East.

Police said they found a crossbow alongside the bodies and other things they say may have been used as weapons.

Suspect's apartment investigated

Investigators also confirmed an evacuation in Toronto's downtown area after the discovery of a suspicious package they said was linked to the three deaths.

"During the time of this investigation a secondary scene was discovered," Carbone said. "This is an apartment associated to Mr. Brett Ryan," Carbone said.

Police received a call about the package at the building near the intersection of Queens Quay and Lower Simcoe Street around 2:30 p.m. ET on Thursday. Carbone would not specify what was found at the apartment.

"I would like to assure the public that at no time was there any danger to [anyone]," he said.

Police are looking to speak with anybody who has been in contact with Ryan, specifically on the day the homicides took place.

Brett Ryan is shown in this image from Facebook. The 35-year-old Toronto man is facing murder charges in a triple homicide that police say involved a crossbow. (Facebook/Canadian Press)

"We certainly would like to speak to any of his co-workers," Carbone said. "We understand he may have attended a local university. If anyone has ever had any contact with this individual I would respectfully request they contact us."

Police are still investigating the two scenes connected to the crime, going through surveillance footage and speaking to witnesses.

"This investigation is very unusual," said Carbone.

Anybody who has been in contact with Ryan is asked to contact Toronto police's homicide unit directly at 416-808-7400 or Crime Stoppers anonymously.