A former Los Angeles County juvenile hall guard has been sentenced to a year in jail for letting five minors beat a boy she wrongly believed had taken her cell phone.

Deputy District Attorney Natalie Adomian said Wednesday the judge also ordered Diane Buchanan to serve four years probation, complete a counseling program and perform community service.

The 38-year-old was convicted of child abuse. Buchanan lost her phone at the Sylmar juvenile hall in 2005. One boy said the victim had flushed the phone down a toilet.

Prosecutors said Buchanan opened the victim's cell door and allowed five boys in to attack him. Afterward, she did not report the incident or seek medical help.

She later found her phone in her car.