Wife’s body buried in home basement

CALGARY — The Crown says a man accused of killing his wife confessed to undercover officers that he strangled her and buried her body in the basement of the home they shared with their two children.

The trial of Allan Shyback, who is charged with second-degree murder and causing an indignity to a body, began on Tuesday. He is accused of killing Lisa Mitchell, 31, who was last seen walking from her house to a convenience store in October 2012.

An undercover operation police launched in 2013 ended with Shyback’s arrest in Winnipeg a year later.

“It ended on Dec. 5, 2014, with the accused confessing to have killed Lisa Mitchell by strangling her to death,” prosecutor Heather Morris said in her opening statement. “The accused took significant steps to cover up the death and cover up his role in the death. At the end of the day, the Crown will prove the accused intended to cause the death of Lisa Mitchell.”

Mitchell’s mother said her daughter and Shyback had a “volatile” on-again, off-again relationship.

Court heard a search of the crime scene that included the home’s computer revealed an Internet history on how body decomposition is affected by salt, lye, concrete, lack of air and lack of insect activity.

Police Const. Karl Sudyk described the recovery of the body from the basement, and that the cement “was removed with brute force ... sledgehammers, picks, air chisel, hammers.”

Alberta’s assistant medical examiner at the time said Mitchell’s body was brought into the autopsy room in two plastic tubs and appeared to be encased in white pellets.

“I believe it was a mixture of cat litter . . . mixed in with salt tablets,” said Dr. Jeffery Gofton.

The cause of death appeared to be a fractured thyroid cartilage, he said.