United States Attorney Alison J. Ramsdell announced that William Henry Riese, a 34-year-old man from Rapid City, South Dakota, has been sentenced to over 21 years in federal prison. The sentencing was carried out by U.S. District Court Judge Karen E. Schreier on May 30, 2025.
Riese was convicted of several offenses including attempted sexual exploitation of a minor, attempted enticement of a minor using the internet, attempted receipt of child pornography, and attempted transfer of obscene material to a minor. Following his prison term, Riese will be under supervised release for five years. He is also required to pay $400 in special assessments to the Federal Crime Victims Fund and forfeit the cell phone used in his crimes.
The case against Riese began with an indictment by a federal grand jury in August 2022. He was found guilty after a jury trial concluded in February 2025 in Rapid City.
Riese’s arrest followed an undercover operation targeting online predators during the Sturgis Bike Rally. He had engaged in explicit communication with someone he believed to be a 14-year-old girl and arranged to meet her for unlawful purposes. Instead of meeting the minor, Riese encountered law enforcement agents and was arrested on the spot. He has remained in custody since then.
This prosecution is part of Project Safe Childhood, an initiative started by the Department of Justice in May 2006 aimed at addressing child sexual exploitation and abuse. The project combines efforts from federal, state, and local resources to apprehend offenders and rescue victims.
The investigation involved Homeland Security Investigations, the South Dakota Division of Criminal Investigation, South Dakota Internet Crimes Against Children Task Force, and the Rapid City Police Department. Assistant United States Attorney Heather Knox led the prosecution.
Following his sentencing, Riese was handed over to the U.S. Marshals Service.
