Following trial, Hamilton man sentenced to 2 years for unlawfully possessing firearms (DOJ)

MISSOULA - A Hamilton man who unlawfully stored a cache of firearms at his house was sentenced today to 24 months in prison, followed by three years of supervised release, Acting U.S. Attorney Mark Steger Smith said.

After a one-day trial on April 13, 2026, a jury found Shawn Ryan Cowan, 46, guilty of unlawfully possessing a firearm.

U.S. District Judge Donald W. Molloy presided.

The government alleged in court documents and at trial that Cowan, who had previously been convicted of multiple felonies, was keeping guns in his home. A tip to law enforcement led investigators to seek a warrant and search Cowan's home.

There they found:

• Ruger SR-22, .22 cal. pistol
• Raven Arms P25, .25 cal. pistol
• F.LLI Pietta Fabrica D'Armi, Big Bore Rough Rider, .357 cal. revolver
• Derya Arms (Derya Silah Sanayi) TM22-A-18, .22 cal. rifle
• Marlin Firearms Co. 20, .22 cal. rifle
• High Standard Sentinel, .22 cal. revolver
• North American Arms NAA22, .22 cal. revolver
• Smith & Wesson 18, .22 cal. revolver
• Derya Arms (Derya Silah Sanayi) VRPA40, 12-gauge shotgun
• Heritage Mfg. Inc. Rough Rider, .22 cal. revolver

Investigators also found various types of ammunition.

Cowan had been convicted previously of aggravated kidnapping, burglary, and possession of dangerous drugs in Montana and so was required to register as a violent offender for life. Cowan, who became belligerent with agents as he was arrested, acknowledged he was "technically a felon," but said he owned guns because his conviction was fraudulently obtained by county officials.

The U.S. Attorney's Office prosecuted the case. The ATF and Ravalli County Sheriff's Office conducted the investigation.