MONTEREY PARK (CBS)  — Felony charges were filed Wednesday against a convicted sex offender accused of sexually assaulting a teenage boy at a Monterey Park gym.

Javier Magdaleno, a 55-year-old transient with a child annoying conviction on his record, pleaded not guilty to one count each of committing a lewd act on a child, indecent exposure with a prior and annoying or molesting a child with a prior.

He is due back in Alhambra Superior Court on May 11 for a preliminary hearing.

Magdaleno was arrested late Monday night in Rosemead in connection with the alleged sexual assault of a 15-year-old boy at the LA Fitness in Monterey Park. Officials believe there may be additional victims, said Monterey Park police Lt. Carrie Mazelin.

Magdaleno is known to frequent LA Fitness locations in Alhambra and Arcadia and Bally’s Fitness in Rosemead, she said.

LA Fitness staff “were very cooperative and provided assistance to the police investigators at the scene,” Mazelin said.

Although teens are welcome at many public gyms, they should always be accompanied by an adult family member if possible, the lieutenant said. Sexual predators frequent such establishments, and parents should talk with their teens about sexual predators in public places, she said.

Anyone with information about the case should contact Monterey Park police investigators at (626) 307-1236.

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