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Press Release

Fort Thompson Man Sentenced for Failure to Register as a Sex Offender

For Immediate Release
U.S. Attorney's Office, District of South Dakota

PIERRE - United States Attorney Alison J. Ramsdell announced today that Chief Judge Roberto A. Lange, U.S. District Court, has sentenced a Fort Thompson, South Dakota, man convicted of Failure to Register as a Sex Offender. The sentencing took place on December 11, 2023.

Mark Fleury, age 48, was sentenced to six months in federal prison, followed by five years of supervised release, and ordered to pay a $100 special assessment to the Federal Crime Victims Fund.

Fleury was indicted by a federal grand jury in July of 2023. He pleaded guilty on September 14, 2023.

Fleury was convicted of Abusive Sexual Contact in 2004. As a result of this conviction, he is required to register as a sex offender and to update his registration within three business days of relocation or changing employment. On May 13, 2023, Fleury moved from his registered address in Fort Thompson to an address in Sioux Falls, South Dakota, but he did not update his sex offender registration. Fleury moved back to Fort Thompson on or about May 31, 2023, at which time he updated his registration. 

This case was investigated by the U.S. Marshals Service and the Rosebud Sioux Tribe Law Enforcement Services. Assistant U.S. Attorney Kirk Albertson prosecuted 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 the U.S. Attorneys’ Offices and the DOJ’s Child Exploitation and Obscenity Section, Project Safe Childhood marshals federal, state, and local resources to locate, apprehend, and prosecute individuals who exploit children, as well as identify and rescue victims. For more information about Project Safe Childhood, please visit

Fleury was immediately remanded to the custody of the U.S. Marshals Service.

Updated December 18, 2023

Project Safe Childhood
Indian Country Law and Justice