Former Gymnastics Coach Admits Engaging in Sexual Activity with Two 13-Year-Olds
ST. LOUIS / Wednesday, September 2, 2026 – A former gymnastics coach on Wednesday admitted engaging in unlawful sexual activity with two 13-year-olds.
Marco A. Zomphier, 32, pleaded guilty in U.S. District Court in St. Louis to two counts of coercion and enticement of a minor. He admitted meeting the first victim in 2012, when she was a member of a YMCA dance/gymnastics program and Zomphier was a coach/member of that program. They began communicating via text messages, the ooVoo video call app and the Kik messaging app. Zomphier praised his victim in those communications, 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.
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, his plea agreement says. On one occasion at her home, he tried to push her into her bedroom. Zomphier’s abuse of the victim ended around May of 2013.
In late 2021, the second victim met Zomphier at the Collinsville gymnastics program where he was a coach. They began communicating via Snapchat. Zomphier’s messages became more sexual in nature in January of 2022. They engaged in unlawful sexual activity in the parking lot of a store near her home and at his home in Bethalto, Illinois.
Zomphier is scheduled to be sentenced on December 2. The U.S. Attorney’s Office will recommend a sentence of 25 years in prison.
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 the case.
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.
Contact
Robert Patrick, Public Affairs Officer, robert.patrick@usdoj.gov.
Source: U.S. Attorney's Office, Eastern District of Missouri
