Police in Ontario say they are looking to speak with anyone that knew 48-year-old Winnipeg man Mitchell Lapa. Police allege he was the lone gunman in a mass shooting Friday morning that killed four people in an Oshawa home.

Durham Regional Police say Lapa was the lone shooter in the incident, and he also died of a self-inflicted gunshot wound.

In a release, the DRP says the incident occurred early Friday morning in the suburban community east of Toronto. They say Lapa was uninvited into the home.

A white pickup truck with Manitoba plates registered to Lapa could be seen in the driveway throughout the weekend.

The deceased have been identified as Chris Traynor, age 50; and his children Bradley, age 20; Adelaide, age 15; and Joseph, age 11, all of Parklane Avenue in Oshawa.

A 50-year-old female injured in the attack is recovering in hospital. According to several media reports, she is the sister of Lapa.

Lapa lived on Dalhousie Drive in Winnipeg. Police say anyone who knew him may be able to provide valuable information, as investigators seek to understand the motivation and reasons for this attack.

If anyone has details or background information about Lapa, they are asked to contact their local police service or one of DRP's lead investigators: Det. McDermott (ext. 5411) or Det. Dorego (ext. 5319) of the Homicide Unit at 1-888-579-1520. Anonymous information can be sent to Durham Regional Crime Stoppers at 1-800-222-TIPS (8477) or online at www.durhamregionalcrimestoppers.ca and tipsters may be eligible for a $2,000 cash reward.