Police: Man beat autistic boy

Mesa police arrested a man who they said beat a mentally disabled teen Friday morning.

According to police reports, Brian Salvador Arredondo, 18, beat the 13-year-old, who police described as autistic, bipolar and mentally disabled, with a closed fist. Arredondo was baby-sitting the boy at the time.

The boy's mother witnessed the assault as she came home from work, and she had to pry Arredondo away from her son as he continued to beat the boy, police said.

According to police, the beating began after the child escaped from the house near 48th Street and Adobe Road. The boy started running away from Arredondo, who told police he "lost his temper" and began to punch the victim in the face, police said.

Police said Arredondo confessed to the beating, and officers arrested him on suspicion of child abuse.