A 7-year-old boy who authorities say was severely beaten by his dad on Father's Day has died in Massachusetts.

UMass Memorial Medical Center nursing supervisor Elaine Grady said Sunday that Nathaniel Turner was removed from a ventilator early Saturday morning.

Nathaniel was declared brain dead Tuesday after his father allegedly slammed the boy's head against a wall in his Worcester home so hard that it left a dent.

Leslie Schuler and his live-in girlfriend are charged with assault, but authorities have said they are now conducting a murder investigation. Their lawyers didn't immediately return phone calls seeking comment Sunday.

Results of an autopsy performed Saturday are expected in a few weeks.

Nathaniel had been living with his father since Memorial Day.