Local Man Sentenced For Assaulting Officer On Wind River Reservation

A 24-year-old Riverton man has been sentenced to federal prison after spitting on a Bureau of Indian Affairs officer during an arrest on the Wind River Reservation — a crime that, while brief in action, falls under the umbrella of assaulting a federal officer.

Dustin Vance Big Medicine Jr., of Riverton, was sentenced to four months and 11 days in prison followed by three years of supervised release for assaulting a federal officer.

According to court documents, the incident happened June 4, 2025, at tribal housing on the Wind River Reservation. A Bureau of Indian Affairs officer responded to reports that Big Medicine had been acting violently toward emergency medical services personnel.

After placing him under arrest, the officer began escorting Big Medicine to a patrol vehicle. Prosecutors say that while being walked to the car, Big Medicine gathered saliva in his mouth and spit on the officer’s ear and face.

Under federal law, intentionally assaulting, resisting or impeding certain federal officers — including BIA officers — can carry felony penalties, even when the physical conduct does not involve a weapon or serious bodily injury.

The Bureau of Indian Affairs investigated the case. Assistant U.S. Attorney Kerry J. Jacobson prosecuted it. Big Medicine was indicted Sept. 16, 2025, and pleaded guilty Dec. 10, 2025.

Federal Jurisdiction on the Reservation

Crimes involving assaults on federal officers in Indian Country are prosecuted in federal court because of the unique jurisdictional framework governing reservations. The Wind River Reservation, home to the Eastern Shoshone and Northern Arapaho tribes, falls under federal criminal jurisdiction for many serious offenses, particularly when federal officers are involved.

Assault cases in Indian Country make up a significant portion of Wyoming’s federal criminal docket each year. According to annual reports from the U.S. Attorney’s Office for the District of Wyoming, violent crimes — including assault resulting in bodily injury, domestic assault, strangulation and assaults on law enforcement — consistently represent a large share of federal prosecutions tied to the reservation.

While high-profile cases often involve weapons or serious injuries, even lower-level physical acts such as spitting can be charged federally when directed at law enforcement. Courts have historically treated spitting as a form of assault because it involves intentional offensive physical contact.

Broader Challenges

Law enforcement agencies operating on the Wind River Reservation — including tribal police, the Bureau of Indian Affairs and the FBI — frequently respond to calls involving intoxication, domestic disturbances and mental health crises. First responders, including EMS crews, have at times reported being assaulted while attempting to provide aid.

Federal officials have repeatedly emphasized that assaults on officers and emergency responders will be prosecuted to the fullest extent of the law, arguing that such accountability is necessary to maintain public safety in often high-stress response environments.

Big Medicine will serve his custodial sentence in federal prison before beginning three years of supervised release under standard federal conditions.

The case underscores how even brief, chaotic encounters on the reservation can quickly escalate into federal felony charges — and how the intersection of tribal land, federal authority and frontline emergency response continues to shape Wyoming’s criminal justice landscape.