Bakersfield Police have arrested a 19-year-old woman in the death of of 2-year-old Kayli Bearden.

Melissa Blanchard of Bakersfield was arrested for murder Wednesday night, authorities said. Autopsy results released Thursday indicate Bearden died of "abusive head injuries, and the manner of death was homicide."

Bearden's father left the girl with Blanchard, his girlfriend, on Sunday while he went to the store. When he came back, Bearden was blue and unresponsive, family sources said.

The toddler died Tuesday afternoon after spending two days on life support at Children's Hospital of Central California in Madera County.

"We just want answers," family friend Nichole Nance said tearfully. "We want to know why - why did it happen."

The five-hour autopsy Wednesday revealed blunt force trauma to the child's skull. Blanchard admitted causing the trauma after detectives questioned her more than once.

Blanchard has no prior criminal offenses, according to court records.