Ontario couple committed to stand trial in family members' deaths

Melissa Merritt is escorted at provincial court in Halifax on Wednesday, Jan. 29, 2014. (Andrew Vaughan / THE CANADIAN PRESS)

TORONTO -- An Ontario couple accused of killing a man and his mother have been committed to stand trial in their deaths while changes have been made to the charges they faced in the death of the man's father.

Melissa Merritt and her common-law husband Christopher Fattore will be tried for first-degree murder in the deaths of Merritt's ex-husband, Caleb Harrison, and his mother, Bridget Harrison.

Last year, they were also charged with first-degree murder in the death of William Harrison -- who was Caleb's father and Bridget's husband -- but a judge has discharged Merritt on that count, citing insufficient evidence, and has reduced the charge to second-degree murder for Fattore.

Lawyers for Merritt and Fattore say the pair could stand trial as early as September.

The case is expected to be a complex one, involving an intricate web of family relations.

All three Harrisons were found dead in the same Mississauga, Ont., home over several years.

Caleb Harrison was 41 when he was found dead at the family home in August 2013.

His 63-year-old mother had been found dead in 2010. Her death was first classified as suspicious, but it was only when officers started investigating her son's death that they concluded both mother and son had been asphyxiated.

Police then reopened an investigation into the 2009 death of William Harrison, who also died in the same home. Investigators had originally determined he died of natural causes.

Merritt and Fattore were arrested near Bridgewater, N.S., in January 2014, where they had moved shortly after Caleb Harrison's death.

They were transferred to Ontario, where their case is being heard in the city of Brampton.

Merritt and Caleb Harrison had two children and split up in 2005 -- the same year she and Fattore met, police have said.

Fattore and Merritt also had children of their own, police have said.