ST. LOUIS — A former gymnastics coach admitted Wednesday, Sept. 2, 2026, in U.S. District Court in St. Louis that he engaged in unlawful sexual activity with two 13-year-olds he met through gymnastics programs.
Marco A. Zomphier, 32, pleaded guilty to two counts of coercion and enticement of a minor. The U.S. Attorney’s Office said it will recommend a sentence of 25 years in prison.
Zomphier admitted meeting the first victim in 2012, when she was a member of a YMCA dance and gymnastics program, and he was a coach and member of the program. They began communicating by text message, the ooVoo video call app and the Kik messaging app.
In those communications, Zomphier praised the victim, flirted with her and professed his love for her. “I love you…. You’re the only girl I want to be Mrs. Zomphier,” he wrote at one point.
According to his plea agreement, Zomphier convinced the victim to have him over at her house. There, he molested her but was unsuccessful in coercing her to have sex with him. On one occasion at her home, he tried to push her into her bedroom. His abuse of the victim ended around May 2013.
In late 2021, the second victim met Zomphier at the Collinsville gymnastics program where he was a coach. They began communicating on Snapchat. Zomphier’s messages became more sexual in nature in January 2022. They engaged in unlawful sexual activity in the parking lot of a store near her home and at his home in Bethalto.
Zomphier is scheduled to be sentenced Dec. 2, 2026.
The Jefferson County Sheriff’s Office, the St. Louis County Police Department, the Bethalto Police Department and the FBI investigated the case. Assistant U.S. Attorney Michael Hayes is prosecuting it.
This case was brought as part of Project Safe Childhood, a nationwide initiative to combat the growing epidemic of child sexual exploitation and abuse launched in May 2006 by the Department of Justice. Led by U.S. Attorneys’ Offices and the Criminal Division’s Child Exploitation and Obscenity Section, Project Safe Childhood marshals federal, state, and local resources to better locate, apprehend and prosecute individuals who exploit children via the Internet, as well as to identify and rescue victims. For more information, please visit www.justice.gov/psc.
