A former cheer coach charged with allegedly raping a teenage girl in Jefferson County last year is facing additional charges in St. Louis County for an alleged sexual assault of another minor in 2013. Both alleged victims were younger than 14, court records said.
The St. Louis County Prosecuting Attorney’s Office on June 10 charged Marco Anton Zomphier, 31, of St. Louis with two counts of first-degree statutory sodomy, an unclassified felony punishable by five years to life in prison; and sexual contact with a student by a teacher, a class D felony that carries a penalty of up to seven years in prison, according to court documents.
The Jefferson County Prosecuting Attorney’s Office in December 2024 charged Zomphier with first-degree statutory rape or attempted statutory rape of someone younger than 14, statutory sodomy or attempted statutory sodomy of someone younger than 14, first-degree rape or attempted rape and two counts of first-degree rape or attempted rape. All five charges are unclassified and punishable by five years to life in prison, court records show.
Zomphier has been held without bail since Dec. 6, 2024, in the Jefferson County Jail in Hillsboro. A five-day jury trial is scheduled to begin on Sept. 15 in Jefferson County, according to court documents.
According to a probable-cause statement filed by St. Louis County Police, a woman said Zomphier was her coach at a St. Louis County YMCA, and he allegedly raped her more than a decade ago.
“The courageous survivor in our case told St. Louis County Police detectives that she came forward with these allegations of abuse more than a decade after the abuse occurred because she saw that her abuser was accused in a similar case in Jefferson County,” St. Louis County Prosecuting Attorney Melissa Price Smith said in a statement. “This is a reminder of how difficult it is for survivors of child sexual abuse to come forward and seek justice and how important it is.”
In the probable-cause statement filed by the Jefferson County Sheriff’s Office in September 2024, an alleged victim said Zomphier was her cheer coach, and he sent her inappropriate messages through Snapchat.
The girl said starting in April 2022, Zomphier would drive to either her home or school to pick her up. She said on at least three occasions, he drove to either the Target store or Schnucks grocery store in Arnold and allegedly raped her in the car, the report said.
The girl said the first alleged incident ended because Zomphier’s wife called him, and she said there was a baby in the car during one of the other alleged incidents, according to the report.
The girl told investigators she felt she could not say no to Zomphier because he allegedly threatened to post sexually explicit photos and videos of her online and that he would shoot himself outside her window if she told anyone about the incidents, the report said.
Zomphier was a U.S. All-Star Federation certified cheerleading and tumbling instructor in Missouri, Illinois and Arizona, according to an online USASF directory. His coaching credentials were revoked by USASF before his arrest.
He is now on the organization’s “Restricted and Ineligible List” and is permanently ineligible to coach because of athlete protection policy violations. The list, which includes dozens of other former coaches and is posted on usacheer.org, details those the USASF feel “could pose a potential risk to the broader sport community.”
St. Louis County Police said in a statement that investigators believe there may be more victims. Anyone who believes they were a victim of Zomphier should call the St. Louis County Police at 314-615-5400.
“If there are any other survivors of abuse from this defendant or any other abuser, we encourage you to come forward,” Price said in a statement. “Your voice matters. Prosecutors, police and our community partners are here to offer support for survivors.”