EL CAJON, Calif. -- A Ramona man was convicted Wednesday of voluntary manslaughter for killing his wife and burying her body in the backyard of their home.

Jurors deliberated over parts of four days before finding Keith Harold Turner guilty of strangling 44-year-old Toby Turner on Sept. 19, 2005.

Turner, 57, faces between probation and 11 years in prison when he is sentenced Jan. 23 by El Cajon Judge William McGrath.

The defendant's 25-year-old stepson, Sean Turner, told authorities last year that he heard the sounding of breaking glass, then the sound of something being dragged the night his mother died.

The stepson said he saw his stepfather standing over his mother's body and saw the defendant put pressure on her neck with his foot.

Investigators uncovered Toby Turner's remains a year ago in two shallow graves after her son came forward and told them what he saw.

The stepson said Turner told him that he had to choke the victim three times before she died. The stepson said his stepfather asked him to help bury the body, but he refused.

Sean Turner said he moved to San Francisco after the murder because he was scared and the defendant had threatened him.

The stepson said he returned to San Diego County in October 2007 to reunite with his biological father, who convinced him to go to the police.

Defense attorney Tom Warwick told the jury that his client wasn't guilty of murder because the victim used methamphetamine, was mentally ill and pushed Turner to the breaking point by living with Sean Turner's biological father on and off for two years before her death.