A man and woman found dead in a murder-suicide in Richmond Hill are believed to be mother and son. York Regional Police say the bodies of Karen Costa, 52, and Jeffrey Costa, 22, were found at a home on Dunvegan Drive, near the intersection of Yonge Street and Highway 7, on Thursday morning.

Both were found with obvious signs of trauma and pronounced dead at the scene.

Neighbours of the victims that the Costa family had lived at the residence for nearly 30 years. Karen Costa, who worked at SickKids hospital between 1985 to 2015, had three children but only one lived at home.

“I’m very surprised because I’ve never heard of anything… No fighting, no arguments outside. Very shocked,” said one neighbour.

“Oh my god, I just saw her. I can’t believe it,” said another.

The incident is considered isolated and investigators say they are not looking for any suspects but are still trying to determine what led to the killing.