A registered sex offender will return to prison for secretly videotaping women in the restrooms at two Cobb County salons, the District Attorney said Monday.

Mark Allan Storch, 56, of Atlanta, must spend five years of his 20-year sentence in prison, Superior Court Judge Gregory Poole ruled Monday morning. When Storch is released from prison, he must serve 15 years on probation and cannot have any type of video-recording device, including a smartphone, according to the ruling.

Storch pleaded guilty to 25 counts of invasion of privacy for recording the women in July 2012, DA Vic Reynolds said.

Police arrested Storch in August 2012 when a salon employee and a customer noticed a camera on the ceiling, The Atlanta Journal-Constitution previously reported. At the time of his arrest, Storch owned two Salon Avenue Suites, including one on Sandy Plains Road in east Cobb and another on Loring Road in Kennesaw. He was indicted in July 2013.

“Unbeknownst to the contractors and the clients of the beauty businesses, Mr. Storch hid video cameras in various locations throughout the suites, spying on and recording women in various stages of undress,” Assistant DA Lindsay Gardner said in an emailed statement. “Storch’s actions ripped away any sense of privacy these women have in secure settings, and actions such as these will not be tolerated in Cobb County.”

Storch has previously served in state prisons three times since 1991, according to the Georgia Department of Corrections. Most recently, he was released in December 2008 after serving more than four years following a conviction on drug and aggravated assault with intent to rape charges, records show.

Ten days after his most recent release from prison, Storch was added to the Georgia Sex Offender Registry.