Spearfish Man Sentenced to Over 5 Years in Federal Prison For Possessing Unregistered Firearms

RAPID CITY - United States Attorney Ron Parsons announced today that U.S. District Judge Camela C. Theeler has sentenced a Spearfish, South Dakota, man convicted of two counts of Possession of an Unregistered Firearm. The sentencing took place on October 19, 2026.

Cole Nygaard, 45, was sentenced to a total of five years and 11 months in federal prison, followed by three years of supervised release and ordered to pay $200 in special assessments to the Federal Crime Victims Fund.

Nygaard pleaded guilty to the charges on July 20, 2026.

In January 2024, in Lawrence County, Nygaard was the passenger in a vehicle that was stopped by law enforcement. Officers were looking for the driver after receiving reports that he intended to kill someone. Inside the car were three firearms with silencers affixed to the end of the barrels. The silencers were devoid of any markings or serial numbers and were not registered in the National Firearms Registration and Transfer Record ("NFRTR") as required by law. Nygaard's possession of the unregistered silencers was a violation of federal law.

On January 27, 2026, law enforcement conducted a search of Nygaard's residence after learning he was making pipe bombs and indicated he would use them on others and a business. Inside the house, law enforcement officers discovered nine improvised explosive devices (IEDs) that Nygaard manufactured, including metal pipe bombs and a victim-operated metal box that could be readily assembled into a destructive device. All destructive devices must be registered with the NFRTR-these were not. One of the smaller IEDs detonated when law enforcement officers attempted to render the device safe. Fortunately, due to precautionary measures taken by them, no one was injured because of the explosion.

Among additional items recovered were:

Pipe bombs found throughout Nygaard's residence, including in his kitchen, garage, and in each of his three vehicles.

• Several firearms and thousands of rounds of ammunition discovered in a secret gun room.
• Nineteen firearms from elsewhere in the residence, including a flare gun that had been converted into a firearm capable of firing 12-gauge shotgun shells.
• Several containers of an explosive precursor, potassium nitrate, and numerous other parts used to make destructive devices.
• Several books on how to build destructive devices, how to get revenge on people, and how to poison people.

While in possession of these firearms and destructive devices, Nygaard was a daily user of methamphetamine.

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.

This case was investigated by the Bureau of Alcohol, Tobacco, Firearms and Explosives, South Dakota Division of Criminal Investigations, and the Spearfish Police Department. Assistant United States Attorney Benjamin Schroeder prosecuted the case.

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