BAKERSFIELD, Calif. -- Police arrested a woman Tuesday afternoon in connection with her son's death.

Officers arrested Gloria Grayson, 58, on murder charges after an autopsy ruled the death of her son, Kevin King, 5, was a homicide.

Police got involved in the case Sunday night, when they responded to Mercy Southwest Hospital after King was pronounced dead, according to Sgt. Greg Terry of the Bakersfield police department.

The investigation revealed Grayson called 911 after she found King unresponsive on a bathroom floor in their home on the 9500 block of Spokane Avenue. The autopsy revealed King suffered blunt force trauma to the chest and abdomen, according to the county coroner's office.

Grayson was questioned Tuesday afternoon and taken into custody on murder charges.

She was also the legal caretaker of three foster children in the home. Those children were taken into protective custody. King was Grayson's legal son, Terry said.

Neighbors who spoke with ABC 23 on the condition of anonymity said Grayson and the children moved into the home in October 2008. They expressed shock that Grayson was arrested, saying they never saw signs of child abuse and was always friendly towards them.

No one was at Grayson's home for comment Tuesday night.