{KXLG – South Dakota} A Rapid City man has been sentenced to more than two decades in federal prison for attempted sexual exploitation of a minor and related charges. William Henry Riese, 34, received a sentence of 21 years and eight months in federal prison, followed by five years of supervised release, by U.S. District Court Judge Karen E. Schreier on May 30, 2025.
Riese was also ordered to pay $400 in special assessments to the Federal Crime Victims Fund and to forfeit the cell phone used in the commission of his crimes.
A federal grand jury indicted Riese in August 2022, and he was found guilty at the conclusion of a jury trial in Rapid City in February 2025.
His arrest stemmed from an undercover sex trafficking operation conducted during the Sturgis Bike Rally, which focused on online predators. Over several days, Riese exchanged sexually explicit messages, videos, and photos with an individual he believed to be a 14-year-old girl. He subsequently arranged a time and place to meet the supposed minor for unlawful sex acts. Upon arriving at the predetermined location, Riese was met by law enforcement agents and was immediately arrested. He has remained in custody since his arrest.
This case falls under Project Safe Childhood, a nationwide Department of Justice initiative launched in May 2006 to combat child sexual exploitation and abuse. The project brings together federal, state, and local resources to identify, apprehend, and prosecute individuals who exploit children and to rescue victims. More information on Project Safe Childhood is available at https://www.justice.gov/psc.
The investigation was a collaborative effort involving Homeland Security Investigations, the South Dakota Division of Criminal Investigation, the South Dakota Internet Crimes Against Children Task Force, and the Rapid City Police Department. Assistant United States Attorney Heather Knox prosecuted the case.
Riese has been remanded to the custody of the U.S. Marshals Service.
