A Sioux Falls man has been sentenced to 10 years in federal prison for attempted enticement of a minor. U.S. District Judge Roberto A. Lange delivered the sentence on June 23, 2025, according to an announcement by United States Attorney Alison J. Ramsdell.
William Danery Sebastian, aged 34, will also face five years of supervised release following his prison term and must pay a $100 special assessment to the Federal Crime Victims Fund. Additionally, he is required to register as a sex offender upon his release.
Sebastian was indicted by a federal grand jury in April 2024 and pleaded guilty on March 27, 2025. The conviction arose from an undercover operation in March 2024 where Sebastian engaged in a conversation with someone he believed to be a 15-year-old female on Facebook. The dialogue became sexual, and Sebastian proposed meeting for a sexual encounter. Upon arriving at the designated location, he was arrested by law enforcement officers who had been posing as the teenager.
The investigation involved Homeland Security Investigations, the Lincoln County Sheriff’s Department, and the South Dakota Internet Crimes Against Children Task Force and Human Trafficking Task Force. Assistant U.S. Attorney Elizabeth A. Ebert-Webb prosecuted the case.
This case is part of Project Safe Childhood, an initiative launched by the Department of Justice in May 2006 to combat child sexual exploitation and abuse. The project coordinates efforts across federal, state, and local levels to apprehend offenders and rescue victims.
Following his sentencing, Sebastian was placed into custody by the U.S. Marshals Service.
