MASON CITY, Iowa (AP) — A man accused of video recording four people in a Mason City school staff restroom has pleaded not guilty. Court records say 46-year-old David Bemis entered the pleas Friday to four counts of invasion of privacy. A trial date hasn’t been set.

Investigators say Bemis was a janitor at Clear Creek Elementary School in May 2013 when he hid a video camera in the restroom and recorded four school employees in varying degrees of nudity. Investigators say the recording was found on a computer in Bemis’ home in Mason City. He no longer works for the district.

Clear Lake Superintendent Doug Gee says an investigation began in January after the district learned about an incident occurring four to five years ago. He says no students were recorded.