PHOENIX - Police say an 18-year-old man used a pay phone near 15th Avenue and Missouri at 2 a.m. Saturday to call 911 and report the 3-year-old girl he was watching had stopped breathing.
Officers attempted to revive the child, but CPR attempts failed.
Police arrested 18-year-old Martwain Mackey and charged him with first-degree murder and two counts of child abuse.
He was watching the child for his girlfriend, who was working. In their apartment, officers found a 1-year-old girl, who was also injured from a beating.
Police say the suspect confessed to the crime and they're looking into what role, if any, the girls' mother might have played.
No motive for the beatings was given, and it's unclear if drugs were a factor.