A Delaware man has been charged with invasion of privacy after he was caught installing secret recording devices inside the changing rooms of two stores in the King of Prussia Mall earlier this month, Upper Merion police said Friday.

Joseph Stevenson, 26, of Smyrna, placed pens with built-in cameras inside the Hollister and Urban Outfitters stores at the mall on July 3, according to police. Stevenson did not have a way to remotely access the data stored on the devices, and Upper Merion Police Chief Thomas Nolan said authorities recovered them before he could view or disseminate the photos of the nine people recorded in the changing rooms.

In addition to the nine counts of invasion of privacy, Stevenson faces charges of disorderly conduct and intercepting communications. He was released after posting $10,000 bail. His attorney, Lee Ciccarelli, did not return a request for comment. As a condition of his bail, he is barred from visiting shopping malls until the criminal case is concluded.

Stevenson’s plot was discovered when one of the people recorded by the camera in Hollister noticed the pen and reported it to the store’s management, Nolan said. Police reviewed the device and saw that it contained pictures of the victims in varying states of undress.

Using surveillance footage from the stores and the mall, officers were able to arrest Stevenson, who was still inside the mall at the time, according to Nolan.

Police have identified and contacted seven of the people who were recorded. Investigators are still trying to contact two others who were inside the Urban Outfitters changing room between 2:20 and 2:55 p.m. on July 3.

Anyone with information about the incident is asked to contact Upper Merion police at 610-265-3232.