Rapid City Man Sentenced to 10 Years in Federal Prison for Attempted Enticement of a Minor Using the Internet

RAPID CITY - United States Attorney Ron Parsons announced today that U.S. District Judge Camela C. Theeler has sentenced a Rapid City, South Dakota, man convicted of Attempted Enticement of a Minor Using the Internet. The sentencing took place on June 15, 2026.

Elmer Hopper, 37, was sentenced to ten years in federal prison, followed by five years of supervised release, and ordered to pay $95 in restitution and $100 in special assessments to the Federal Crime Victims Fund. Forfeiture was also ordered.

Hopper was indicted for the charge by a federal grand jury in August 2025. He pleaded guilty on March 30, 2026.

During the 2025 Sturgis Bike Rally, Hopper initiated communications on the internet-based application Plenty Of Fish with someone he thought was a 14-year-old girl. The girl, in fact, was a Rapid City Police Detective operating in an undercover capacity on Plenty Of Fish, an app used for dating and sexual encounters. Hopper and the undercover persona started communicating through texting. Hopper told her that he wanted someone to lay in bed with him. Later, Hopper explained that he meant that he wanted someone to have sex with, not lay in bed with. Hopper and the undercover persona agreed to meet at West Middle School in Rapid City. When Hopper arrived at the school, he was arrested.

This case was brought as part of Project Safe Childhood, a nationwide initiative to combat the growing epidemic of child sexual exploitation and abuse, launched in May 2006 by the Department of Justice. Led by the U.S. Attorneys' Offices and the DOJ's Child Exploitation and Obscenity Section, Project Safe Childhood marshals federal, state, and local resources to locate, apprehend, and prosecute individuals who exploit children, as well as identify and rescue victims. For more information about Project Safe Childhood, please visit https://www.justice.gov/psc.

This case was investigated by the South Dakota Division of Criminal Investigation's Internet Crimes Against Children (ICAC) Task Force, the Rapid City Police Department, and the Pennington County Sheriff's Office. Former Assistant U.S. Attorney Heather Knox and Assistant U.S. Attorney Benjamin Patterson prosecuted the case.

Hopper was immediately remanded to the custody of the U.S. Marshals Service.