LINCOLNSHIRE, Ill. (CBS) — A 21-year-old Vernon Hills man said he had come back to Stevenson High School to pick up his diploma, but he ended up getting arrested after security found him wandering the halls.

Li Su, of the 0-99 block of Lindon Lane in Vernon Hills, got in trouble after he refused to give his name to security. There is also doubt as to whether he actually earned a diploma from the school.

Su showed up at the Lincolnshire high school before classes started on Feb. 27, and was spotted walking the halls, Police said he ignored security guards who told him to identify himself.

Eventually, Su spoke with school, records officials, giving them his name and saying he was a Stevenson alum who never picked up his diploma.

School employees found Su’s name in their records, but could not confirm whether he was a graduate, Lincolnshire police investigator John-Erik Anderson said. The front office has not changed location recently, and graduates would likely know its location and the school’s security protocols.

Anderson said Su did not appear to be under the influence of anything, but when police arrived, he refused to cooperate. Officers arrested him for trespassing on state-supported property, failing to identify himself to school personnel and resisting a peace officer.

Anderson has a court appearance March 19 in Mundelein. He remains without a diploma.

The Sun-Times Media Wire contributed to this report.

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