RIVERDALE, Md. (AP) — Prince George’s County police have charged a man with killing his girlfriend’s 1-year-old son while he babysat the child.

Twenty-eight-year-old Osman Sesay of Riverdale was arrested Wednesday and charged with first-degree murder and child abuse in the death of Ahmed Jalloh.

Officers say Ahmed’s mother left him with Sesay at his home while she went to work on Aug. 1. Authorities say Seasy called 911 and said he found the child unresponsive. The boy was pronounced dead at a hospital.

An autopsy found that Ahmed died of multiple blunt force injuries.