Prosecutors have charged an Anoka-Hennepin School District employee with sexually abusing two girls over a period of years.

The Coon Rapids man, U.B. Foster Jr., 55, was charged with two counts of criminal sexual conduct. According to a criminal complaint, the victims’ mother, accompanied by her two now-adult daughters, reported to police on Wednesday that Foster had been sexually assaulting her daughters for years, from the time they were children into their teenage years.

The mother reported to Anoka police that she was pawning a computer when the pawn company found a disc and returned it to her. She recently re-examined the disc and discovered seven videos of Foster sexually assaulting one of her daughters, who was 12 or 13 at the time, according to charges.

That victim, who is now 22, told officers that Foster began sexually assaulting her when she was 10 years old, the charges said; he then raped her when she was 11. The sexual assault continued five times a week when her mother was not home and lasted for more than three years, according to charges. On one occasion, Foster videotaped the assault.

Police then interviewed the second victim, who is now 20. She disclosed that Foster started sexually assaulting her when she was about 15, the complaint said.

During the police interview with Foster, he admitted that he had sexually assaulted both girls, charges said.

As of Wednesday, the Anoka-Hennepin School District placed Foster on nondisciplinary administrative leave pending the police investigation. Foster has worked as a technology paraprofessional at Anoka-Hennepin Regional High School since August 2015.

“The complaint under investigation is not related to his employment with the district, and the incidents under review happened before his employment,” the district said in a statement.

The district said that Foster had no disciplinary actions on his record with the district.

The news came in the same week that the principal of Chanhassen High School, Timothy Dorway, 44, was charged with possessing child pornography depicting young girls.