CHICAGO (CBS) — A convicted child sex offender was charged Friday with violating state law after he was caught visiting Brookfield Zoo.

About 12:30 p.m. Friday, a patrol officer noticed a silver Chevrolet Impala stopped in the middle of First Avenue in west suburban Riverside and thought it was disabled, according to Riverside police. When the officer approached the vehicle, the female driver, a 69-year-old Lyons woman, said she had pulled over to wait for her boyfriend, who she dropped off at the south gate of Brookfield Zoo.

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After running the vehicle’s license plate information, the officer found out the woman’s boyfriend, the vehicle’s registered owner, was a convicted child sex offender registered with the Illinois State Police Child Sex Offender List, police said.

The woman was directed to contact her boyfriend to meet officers inside the zoo’s south gate, police said. The man, who was found with a camera and a cellphone in his possession, was then taken into custody.

Rick A. Lucas, 55, of South Beloit, told officers he went to the zoo to see the dinosaur and dragon attraction and take pictures, police said. Officers later recovered a ticket he bought to see the show.

Rick Lucas (Source: Riverside Police)

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Officers learned that as part of his requirement for being released on parole from his child sex offender conviction, Lucas was not allowed to have contact with any children without a supervisor present, police said. Under Illinois law, the Brookfield Zoo is considered a park, which put Lucas in violation of that requirement.

Lucas was taken into custody and charged with one misdemeanor count of a sexual predator and child sex offender in a restricted area, police said. The felony statute did not apply because it requires proof that the offender made physical or verbal contact with a child, something that could not immediately be proven.

Lucas’ phone and camera were confiscated and officers are seeking a warrant to investigate any images, police said. The Illinois State Police Child Sex Offender Registry was also made aware of Lucas’ latest arrest.

Lucas was originally arrested in Waupun, Wisconsin in 1991 and charged with 2 counts of first-degree sexual assault on a child and bail jumping, police said. He moved to Illinois after being released from prison.

He was 30 at the time, and the victim was 6 years old, according to the Illinois Sex Offender registry.

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(Source: Sun-Times Media Wire © Chicago Sun-Times 2017. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)