BILLINGS, Mont. -

Yellowstone County prosecutors say a 19-year-old man charged with killing his great-grandmother in Billings has reached a plea agreement.

Deputy County Attorney Christopher A. Morris tells The Billings Gazette that Robert Alan Thompson has agreed to plead guilty to deliberate homicide in the July 19 death of 77-year-old Shirley Lawrence.

A motion recently filed by Thompson's attorney asks that a change-of-plea hearing be scheduled for Jan. 17.

Prosecutors say Thompson was living with Lawrence and beat and stabbed her during an argument that started when she suggested he get a job or "he was going to be just like his father." Thompson was arrested the next day in Denver.

Morris says the plea agreement hasn't been filed because prosecutors are finalizing their sentencing recommendations.

Thompson remains jailed with bail set at $250,000.