BURBANK, Ill. (CBS) — Two elderly people found dead in their southwest suburban home were shot and stabbed, and their deaths have both been ruled homicides following Thursday autopsies.

A relative called police to the home in the 6400 block of West 83rd Place in Burbank about 9:30 a.m. Wednesday, according to Burbank police.

The victims—identified by the Cook County Medical Examiner’s office as 79-year-old Peter Mountain and 80-year-old Sally Lopez—were found unresponsive in a bedroom, according to police.

Neighbors tells CBS the couple usually locked their home at night like a fortress, but that their dog had been left out all night Tuesday.

Officers found no sign of forced entry to the home, and authorities said Wednesday that they did not believe the shooting was a random act of violence.

However, autopsies on Thursday found that Mountain had died of multiple gunshot wounds and an incise wound to the neck; while Lopez suffered multiple gunshot wounds, incise wounds, and a blunt force trauma injury to the head, the medical examiner’s office said. Both deaths were ruled homicides.

Burbank police were not immediately available for comment Thursday afternoon. The South Suburban Major Crimes Task Force is assisting in the investigation.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2013. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)