CHICAGO (CBS) — A sex offender was arrested after he entered a southwest suburban high school last week while experiencing a medical issue.

Jacob C. Sullivan, 42, approached a faculty member in the parking lot of Plainfield East High School at 12001 Naperville Rd. on Oct. 25 and asked for assistance, according to Plainfield police.

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Jacob Sullivan (Credit: Plainfield police)

When the faculty member said he couldn’t help, Sullivan walked into the school, where he was met by other faculty members who called an ambulance, police said. He was taken to a hospital.

The school resource officer was notified of the incident, and learned Sullivan was a registered sex offender not allowed on school property, police said.

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There were students in the building and on the property at the time, but Sullivan did not have any contact with them.

A warrant was issued for Sullivan’s arrest, and he was taken into custody Tuesday, police said.

Sullivan, a Plainfield resident, was charged with one felony count of presence within a school zone by a child sex offender, police said. His bond was set at $100,000.

He was previously convicted in Cook County of aggravated criminal sexual abuse of a 15-year-old victim, according to the Illinois Sex Offender registry. He was 26 at the time.

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(Source: Sun-Times Media Wire © Chicago Sun-Times 2016. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)