A man accused of killing his girlfriend's 3-year-old daughter and hurting her 1-year-old daughter pleaded guilty on Friday.
Police say 19-year-old Martwane Mackey was babysitting his girlfriend's daughters at their apartment near 15th Avenue and Missouri in June 2011.
Mackey called police from a payphone and told them his girlfriend's 3-year-old daughter wasn't breathing. Officers said it appeared she died from child abuse.
The woman's other daughter also showed signs of abuse but she didn't have any life threatening injuries, police say.
Originally, Mackey pleaded not guilty to his charges but on Friday, he pleaded guilty to second degree murder and two counts of child abuse.
He's expected to be sentenced on Jan. 3.
Follow this story: Teen Faces Child Abuse and Murder Charges