Ohio teacher arrested on child pornography charges after FBI finds him with nude prepubescent girl in hotel room

Mark Altherr, 45, of Cincinnati, has been accused of making a significant number of posts depicting minor victims of sexual exploitation on an online website launched in 2019 that describes itself as a "child pornography community," court documents viewed by WCPO stated.

The FBI investigation showed that Altherr has been an active member of the website since 2021 and made at least 262 posts, many of which depicted child pornography, between December 2023 and continuing into July 2024.

Altherr allegedly responded to a thread titled "3 to 5 year old cuties only," which contained nude images of children. He also reportedly responded to a thread that featured children engaging in sexual activities with an adult male, court documents stated.

Additionally, the FBI investigation found that Altherr allegedly described his own sexual abuse of children in posts on the website, which involved a "4 year old I was looking after," an "8 year old who had a crush on me," and a "10 year old neighbor."

During the investigation, the FBI determined that Altherr was a fitness education teacher at Delshire Elementary School. Because of his position of authority with children, the FBI determined it was "necessary" to find him. FBI agents were dispatched to his home in Cincinnati on July 26, but he was not there. According to the FBI, investigators located his vehicle through a cell phone ping and discovered he was in a public location in Columbus, Ohio. FBI agents were dispatched to the location.

Court documents stated that "at approximately 7:54 pm on July 26, 2024, the Agent observed an individual fitting the description of Altherr enter the vehicle with a minor female." The agents watched Altherr drive himself and the minor child to a hotel in the Columbus area.

FBI agents established that the child was in "imminent danger" after reviewing images Altherr had posted to the website and executed a probable cause arrest on Altherr. Upon entering the hotel room, agents discovered a minor girl, completely nude, court documents state.

Altherr was taken into custody and is being held in the Butler County Jail on an FBI retainer. He has been charged with one count of felony distribution of child pornography and one count of felony possession of child pornography. He faces up to 40 years in prison if convicted on charges.

Later that evening, FBI agents executed a search warrant on his home and found electronic devices that had images and videos depicting child sex abuse, per court documents. Altherr's personal Facebook account is filled with several anti-Trump, anti-police, and leftwing posts.

The Oak Hills School District said in a statement to WCPO that Altherr has been placed on administrative leave and "is prohibited from being on school grounds or having any contact with students or staff". The school intends to initiate termination proceedings. "The Oak Hills Local School District is working closely with and fully cooperating with the FBI and law enforcement agents regarding the ongoing investigation. When more information becomes available, and legally permissible, we will share it with families and the community."

The FBI urged individuals who suspect that they or a loved one may have been a victim of Altherr's actions to complete a brief online form.