JUPITER, Fla. (AP) — A Florida man faces child sex charges after investigators found videos and photos of an assault on a seemingly unconscious teenager.

The Palm Beach County Sheriff’s detectives found the images earlier this month while looking through hundreds of pornographic images found on Richard Van Fossen Jr.’s cellphone, which was seized during a Dec. 5 search of his home in Jupiter.

Charges of sexual battery on a minor and of production of child pornography were filed Wednesday against Van Fossen, 50, and his on-and-off-again 48-year-old girlfriend, the Palm Beach Post reported. The girlfriend’s name wasn’t included in the story.

The investigation began over the summer when someone alerted the National Center of Missing and Exploited Children that Van Fossen was sharing pornographic images of children. Authorities found 30 illegal images on one phone and other devices.

One image shows him sexually assaulting the teen, according to heavily redacted court records.

Van Fossen has been in the Palm Beach County Jail since Dec. 5 when authorities arrested him on dozens of counts of possessing child pornography.

Van Fossen’s attorney, Michael Salnick, said his client plans to plead not guilty to the charges.