Alison J. Ramsdell U.S. Attorney | U.S. Attorney for the District of South Dakota
United States Attorney Alison J. Ramsdell announced that a Sioux Falls man has been sentenced for failing to register as a sex offender. U.S. District Judge Roberto A. Lange sentenced Adrian Fast Dog, 45, to two years and nine months in federal prison, followed by five years of supervised release. Fast Dog is also required to pay a $100 special assessment to the Federal Crime Victims Fund.
Fast Dog was indicted by a federal grand jury in June 2024 and pleaded guilty on April 10, 2025. The charges relate to his failure to register as a sex offender between June 25, 2024, and February 13, 2025, as mandated by federal law due to his previous conviction for a sex offense.
The investigation was conducted by the United States Marshals Service, with Assistant U.S. Attorney Ann M. Hoffman prosecuting the case.
This case is part of Project Safe Childhood, an initiative launched in May 2006 by the Department of Justice to address child sexual exploitation and abuse. The project brings together federal, state, and local resources to prosecute offenders and rescue victims.
Fast Dog has been remanded into custody by the U.S. Marshals Service.
