By Kathleen Brady Shea, Managing Editor, The Times

Joseph “Joey” C. Kolimaga, accused of secretly videotaping female co-workers, waived his preliminary hearing today.

An employee at a West Chester dental surgery practice made a disconcerting discovery in August: a cell phone set to video-record was lying on the floor of the female employees’ changing room.

A subsequent investigation led to multiple invasion-of-privacy charges against Joseph “Joey” C. Kolimaga, 27, a co-worker at the practice who was arrested Sept. 18 and waived his preliminary hearing today before Magisterial District Judge William D. Kraut.

In a packed courtroom, Assistant District Attorney Thomas Ost-Prisco said he expected the case to be resolved with a plea agreement, and in exchange for the waiver, he told defense attorney Joseph P. Green Jr. that he would not seek prison time for Kolimaga.

Sentencing guidelines for the offense call for probation to one month in jail. Ost-Prisco said he had discussed the proposed waiver with the five alleged victims, who agreed to it. Under the waiver agreement, Ost-Prisco said Green preserved his right to challenge the number of counts of  invasion of privacy – 18 – against his client.

The alleged victims were accompanied to court by nearly 30 co-workers from Oral and Maxillofacial Surgery Associates of Chester County, which has offices in West Goshen and Kennett Square. Kraut instructed Kolimaga, a Coatesville-area resident who is free on bail, to have no contact with any former or current workers at the practice. The only exception is his mother, Joan Kolimaga, the former office manager in West Goshen.

West Goshen police began the investigation Aug. 16 after the discovery of the cellphone, which was traced to Joseph Kolimaga, the criminal complaint said. Discussion in the office about the phone led to another revelation: In 2006, a female co-worker who had dated Kolimaga confronted him about a videotape she found in his residence that contained “footage of several staff members in various state of undress at the Oral Surgery office” in West Goshen, the complaint said.

Police interviewed the former girlfriend, who had shared the contents of the video with a co-worker who recognized herself and other staff members. Both women told police that Kolimaga insisted he was young and stupid at the time and didn’t do things like that anymore, the complaint said.

Detectives conducted interviews with five other female employees, none of whom are being identified because of the nature of the offenses, all of whom were distressed to learn about the existence of the videotape from police. The women were shown the video in private, recognized themselves, and said they wanted to press charges against Kolimaga, the complaint said.