A jury has convicted a woman and her common law husband of murder in the sensational asphyxiation deaths of a mother and her grown son over a five-year period in Mississauga. Melissa Merritt, 37, is guilty of first-degree murder in the death of her former husband Caleb Harrison. He was the father of her two of her six children. The jury also found Merritt’s common-law partner Christopher Fattore, 40, guilty of first-degree murder in the deaths of Caleb Harrison and Bridget Harrison, Caleb’s mother. Fattore was found not guilty of second-degree murder in the death of Bill Harrison, Caleb’s father. All three victims were found dead in the same Mississauga family home between 2009 and 2013. The investigation began when Caleb Harrison was found dead in the home in August, 2013 at the age of 41. Harrison’s 63-year-old mother Bridget had been found dead in the home in 2010 but her death had been classified as suspicious. It was later ruled a murder following the investigation of Caleb Harrison’s death. That development also prompted police to reopen an investigation into the 2009 death of Bill Harrison. Investigators had originally determined that he had died of natural causes, however they later said that he too had been murdered. The Crown alleged the crimes were motivated by a bitter custody battle between Merritt and the Harrisons. Merritt had four additional children with Fattore for a total of six. They are being cared for but no details are known.