FARGO (AP) - Court records show a former Concordia (Minn.) College janitor accused of videotaping nude athletes had a 1996 theft conviction from a North Dakota State University incident.

Cass County court records in Fargo say Steven Sopko confessed to taking six keys for a NDSU residence hall, and to stealing a master key to the NDSU Memorial Union while he was a custodial employee.

Sopko, 31, who has worked at Concordia in 1999, is charged in Minnesota with seven counts of gross misdemeanor interference with privacy. He is accused of aiming a hidden camera at a women's shower on campus. Police said female athletes discovered the video camera in an air duct in the locker room.

Sopko, of Dilworth, Minn., has not returned calls seeking comment.

Concordia spokesman Roger Degerman said he could not comment on whether officials knew about Sopko's 1996 theft conviction. "If we had access to information that indicated a red flag, we obviously would not hire that person," he said.

Concordia does background checks on all custodians and physical plant employees through the Minnesota Bureau of Criminal Apprehension, Degerman said.

If an applicant has lived in Minnesota less than 10 years, Concordia requests an FBI background check, he said.

"Whatever was legally required for us, we did indeed do that," he said.

Sopko also worked for Moorhead Senior High School from 2003 to 2005 as a night custodian, said Ron Nielsen, the district's personnel director.

A background search did not reveal Sopko's theft conviction, Nielsen said. Moorhead schools routinely do background checks through the Minnesota BCA, he said.

Sopko resigned from Moorhead Senior High and did not have any disciplinary items in his file, Nielsen said.

Concordia fired Sopko the same day Moorhead police arrested him for the videotaping incident.

The incident is prompting Concordia officials to take a closer look at hiring practices, Degerman said.

Court records show another Concordia custodian has a 1999 misdemeanor conviction for harassment in Cass County. Degerman said he could not comment on whether Concordia knew about that offense when the school hired him.

Legislators last year gave the North Dakota University System authority to require background checks for certain positions, including custodians, residence hall managers and others with master keys.

The legislation was prompted by the killing of Valley City State University student Mindy Morgenstern. Moe Gibbs, who was convicted of killing her, had worked as a night security guard for the Valley City State and as a Barnes County jailer. He had an earlier conviction for attempted murder under another name.