A woman and her common-law husband were arrested Tuesday in Nova Scotia and charged with killing her ex-husband and his mother, who died three years apart in Ontario, police said.
Caleb Harrison, 41, was found dead last August in a home in Mississauga, Ont. — the same home where his mother Bridget Harrison, 63, died in 2010.
At the time her death was classified as suspicious, but when officers started investigating Caleb Harrison's death, they determined both were homicides and both mother and son were asphyxiated.
Police have now also reopened the investigation into the 2009 death of Caleb Harrison's father, William Harrison, who also died in the same home.
Investigators originally determined he died of natural causes, but they are taking another look and are treating his cause of death as undetermined.
"When Caleb Harrison was found we were going to do a complete 360 on his life and on the life of the family and basically that investigation led us to where we are today," said Peel Regional Police Insp. George Koekkoek.
Melissa Merritt, 33, and her common-law husband, Christopher Fattore, 36, were arrested near Bridgewater, N.S., where they moved shortly after Caleb Harrison's death.
The couple will appear in court Wednesday morning in Halifax and is expected to be sent back to Ontario to face two counts each of first-degree murder.