Spearfish Man Sentenced to 5 Years and 11 Months: Nine Homemade Explosive Devices and Unregistered Silencers Found at His Home
The U.S. Attorney's Office for the District of South Dakota announced that Cole Nygaard, 45, of Spearfish, South Dakota, was sentenced by U.S. District Judge Camela C. Theeler to five years and 11 months in federal prison, followed by three years of supervised release, on two counts of possession of an unregistered firearm. He was also ordered to pay a $200 special assessment to the Federal Crime Victims Fund. The sentencing took place on October 19, 2026; Nygaard had pleaded guilty on July 20, 2026, and was immediately remanded to the custody of the U.S. Marshals Service.
The case began in January 2024, when officers stopped a vehicle in Lawrence County, South Dakota, and found three firearms fitted with silencers; Nygaard was a passenger. The silencers bore no markings or serial numbers and were not registered in the National Firearms Registration and Transfer Record (NFRTR) as required by law. On January 27, 2026, after learning that Nygaard was making pipe bombs and had indicated he would use them on others and a business, law enforcement searched his residence and found nine improvised explosive devices he had manufactured, including metal pipe bombs and a victim-operated metal box that could be assembled into a destructive device. One of the smaller devices detonated while officers were rendering it safe; thanks to precautionary measures, no one was injured.
The search also recovered pipe bombs throughout the residence, including in the kitchen, garage, and each of his three vehicles; several firearms and thousands of rounds of ammunition in a secret gun room; 19 more firearms elsewhere in the home, including a flare gun converted to fire 12-gauge shotgun shells; containers of the explosive precursor potassium nitrate; and books on building destructive devices, getting revenge, and poisoning people. Prosecutors said Nygaard was a daily user of methamphetamine while in possession of the firearms and devices.
The case was investigated by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), the South Dakota Division of Criminal Investigation, and the Spearfish Police Department, and was prosecuted by Assistant U.S. Attorney Benjamin Schroeder. U.S. Attorney Ron Parsons announced the sentence.
Published by GSM · USA (original Chinese edition)
Photo: 图：南达科他州 Spearfish 市中心清晨（资料图）。Tony Webster 摄，CC BY 2.0，取自维基共享资源。Photo: Downtown Spearfish, South Dakota, at dawn (file photo). Tony Webster, CC BY 2.0, via Wikimedia Commons.
