Adrian Fast Dog, Failure to Register as a Sex Offender, South Dakota 2025

Grimy Times Investigates: Failure to Register as a Sex Offender Lands Sioux Falls Man Behind Bars

SIOUX FALLS, SOUTH DAKOTA – In a shocking turn of events, a Sioux Falls man has been sentenced to nearly three years in federal prison for his failure to register as a sex offender. Adrian Fast Dog, aged 45, was convicted of the crime after a federal grand jury indicted him in June 2024.

Fast Dog, who had previously been convicted of a sex offense in federal court, was required to register as a sex offender for the rest of his life. However, he failed to do so between June 25, 2024, and February 13, 2025. The conviction stems from his deliberate attempt to evade the law and avoid the consequences of his actions.

According to court documents, Fast Dog pleaded guilty to the charge on April 10, 2025. This case was investigated 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, a nationwide initiative launched in May 2006 to combat the growing epidemic of child sexual exploitation and abuse. The U.S. Attorneys’ Offices and the Child Exploitation and Obscenity Section are leading the effort, marshaling federal, state, and local resources to locate, apprehend, and prosecute individuals who exploit children, as well as identify and rescue victims.

Fast Dog was immediately remanded to the custody of the U.S. Marshals Service, where he will serve his two-year and nine-month sentence. He was also ordered to pay a special assessment to the Federal Crime Victims Fund in the amount of $100, and will be subject to five years of supervised release upon his release from prison.

The case serves as a stark reminder of the importance of compliance with sex offender registration laws. The public has a right to know about individuals who have been convicted of sex offenses, and failure to register can have serious consequences. Grimy Times will continue to investigate and report on cases like this, shedding light on the darker corners of our society and holding those responsible accountable.

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