The man accused of killing his girlfriend's daughter is now charged with first degree premeditated murder.
Police arrested 21 year-old Wilie Joe Gonzalez last week for the murder of 2 year-old Esperanza Ontiveros.
He was babysitting the girl and her brother in July while their mother, Leilani Martinez, was at a doctor's appointment.
Paramedics found Esperanza unconcscious.
She died from a skull fracture.
Gonzalez told paramedics she had been pushed down half a flight of stairs her brother.
But investigators say that wouldn't caused the injuries.
Gonzalez could get the death penalty if convicted.