Sioux Falls Man Sentenced to Federal Prison for Illegal Possession of a Firearm

SIOUX FALLS - United States Attorney Alison J. Ramsdell announced today that Chief Judge Roberto A. Lange has sentenced a man from Sioux Falls, South Dakota, convicted of Possession of a Firearm by a Prohibited Person. The sentencing took place on September 29, 2025. 

James Daniel Lathrop, 31, was sentenced to two years in federal prison, followed by three years of supervised release, and ordered to pay a $100 special assessment to the Federal Crime Victims Fund.

Lathrop was indicted by a federal grand jury for Possession of a Firearm by a Prohibited Person in April 2025. He pleaded guilty on July 7, 2025.

The conviction stemmed from an incident on December 24, 2024, in Sioux Falls, SD, when law enforcement officers found Lathrop in possession of a firearm and ammunition. Lathrop is prohibited from possessing firearms and ammunition because of a previous felony conviction and because he is an unlawful user of controlled substances.

This case was investigated by the Sioux Falls Police Department and Homeland Security Investigations. Supervisory Assistant U.S. Attorney Connie Larson prosecuted the case.

This case is part of Operation Take Back America, a nationwide initiative that marshals the full resources of the Department of Justice to repel the invasion of illegal immigration, achieve the total elimination of cartels and transnational criminal organizations (TCOs), and protect our communities from the perpetrators of violent crime. Operation Take Back America streamlines efforts and resources from the Department’s Organized Crime Drug Enforcement Task Forces (OCDETFs) and Project Safe Neighborhood (PSN). Through PSN, the District of South Dakota seeks to bring together all levels of law enforcement and the communities they serve to reduce gun violence and make our neighborhoods safer for everyone. 

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