MINNEAPOLIS (AP) - The son of a couple found fatally stabbed at their home in Eden Prairie has pleaded guilty to killing them with a screwdriver.

Thirty-eight-year-old Nathan Lehman pleaded guilty to two counts of second-degree murder Tuesday in the deaths of Robert and Debra Lehman last May.

Prosecutors say Lehman has a history of mental health problems and methamphetamine addiction and wasn't following orders of his mental health caseworkers.

Police were called to Lehman's parent's house on May 25 after receiving a welfare check call when Robert Lehman failed to show up for work. Officers found the couple dead in an upstairs bathroom.

Lehman is expected to be sentenced Jan. 8.