DULUTH (AP) -- A defendant accused of killing a man during a robbery in St. Louis County has pleaded guilty to murder.

Darrel Mayhew has admitted to killing 70-year-old Larry Watczak at his Duluth home last January. Prosecutors say Mayhew struck Watczak in the head with a bottle, took his computer and emptied his pockets. Watczak died ten days later.

Mayhew pleaded guilty to second-degree unintentional murder Thursday.

Mayhew has agreed, as part of a plea deal, to the St. Louis County Attorney's sentencing recommendation of 20 years in prison. Sentencing is scheduled for June 17.