Prosecutors: Convicted sex offender failed to register

A 36-year-old convicted sex offender, who police say was loitering in a children’s play area in an Elk Grove Village fast-food restaurant, pleaded guilty to failing to notify police of his address as the law requires.

In exchange for Joseph O’Brien’s guilty plea to the class 3 felony, Cook County Judge Ellen Mandletort sentenced him to three years in prison. O’Brien received credit for the 189 days he has spent in custody since his arrest. Cook County prosecutors say he was registered as living in Des Plaines, but had moved to an Elk Grove Village motel without notifying them.

O’Brien was arrested after patrons complained he was staring at an 11-year-old girl in the restaurant’s indoor play area, sheriff’s police said. According to police, O’Brien had been at the location previously and had been asked by restaurant employees to leave the play area.

O’Brien was convicted in 2001 of aggravated criminal sexual abuse, authorities said.