Missoula, Montana – An Idaho man with a history of felony convictions has been found guilty of illegally possessing a firearm following a federal trial involving missing guns, several encounters with Montana residents, and a police chase that ended with his arrest.
First Assistant U.S. Attorney Mark Steger Smith announced that a federal jury convicted Jeremy Thomas Sepanski, 44, on Tuesday after a two-day trial.
Sepanski was found guilty of unlawfully possessing a firearm, an offense that carries a possible sentence of up to 15 years in federal prison.
He could also receive a fine of up to $250,000 and three years of supervised release.
U.S. District Judge William W. Mercer presided over the trial and will determine the sentence after reviewing the U.S. Sentencing Guidelines and other factors required by federal law.
Sentencing has been scheduled for February 5, 2027. Sepanski will remain in custody while awaiting further court proceedings.
According to federal prosecutors, Sepanski was legally prohibited from possessing firearms because he had been convicted of several felonies between 2007 and 2025.
The case developed after a series of unusual incidents in Beaverhead County during the final days of August 2025.
Firearms reported missing after Idaho man stays on Montana property
According to court documents and evidence presented during the trial, Sepanski was driving a blue Toyota sedan in late August 2025 when he stopped at a yard sale near Lima, Montana.
While speaking with the man hosting the sale, Sepanski asked whether he could temporarily stay in an outbuilding located on the property.
The property owner agreed to let him use the building.
However, several days later, the man discovered that a number of his belongings had disappeared. Among the missing items were firearms.
Sepanski was also no longer at the property.
Investigators later connected him to additional incidents involving guns in the surrounding area.
On August 31, 2025, a motorcyclist stopped along the interstate near Monida to take a short break.
While the man was standing near his motorcycle, Sepanski approached him in the blue Toyota sedan and asked whether he wanted to purchase firearms.
The motorcyclist expressed interest, and the two traveled to a nearby gas station so he could obtain cash for the purchase.
Before the transaction could be completed, however, Sepanski unexpectedly disappeared.
He left three pistols in the luggage rack of the motorcyclist’s motorcycle without collecting payment.
A Beaverhead County Sheriff’s deputy happened to be at the gas station at the time.
The motorcyclist approached the deputy, explained what had happened and turned over the three firearms.
Confrontation with residents leads to emergency call
Another incident involving the same blue Toyota took place around that time near Lima.
According to prosecutors, a woman was approaching an intersection when she noticed a blue sedan drive through a stop sign without stopping.
She sounded her horn at the driver before continuing on her way.
The following day, the woman noticed the same vehicle following her around the area.
The situation became more concerning when the blue car repeatedly passed her residence and eventually entered her driveway that evening.
Her husband went outside carrying a rifle and ordered the driver to leave the property.
The driver, later identified as Sepanski, responded by saying that he also possessed firearms.
He then showed the husband a pistol.
Sepanski eventually drove away, and the couple contacted 911 to report the encounter.
Shortly afterward, a Beaverhead County Sheriff’s deputy spotted Sepanski driving the blue Toyota sedan.
The deputy attempted to conduct a traffic stop, but Sepanski refused to stop and accelerated away.
A vehicle pursuit followed as the deputy attempted to catch him.
The chase continued until Sepanski’s car became disabled, allowing officers to take him into custody.
Following the arrest, another resident of Lima approached deputies and reported an additional encounter with Sepanski.
That resident told officers that Sepanski had visited his home and displayed several firearms.
These incidents became part of the federal case examining Sepanski’s possession of firearms despite his earlier felony convictions.
After hearing the evidence presented by prosecutors during the two day trial, the federal jury returned a guilty verdict on the firearm possession charge.
Although Sepanski was accused of possessing stolen firearms, the announced conviction was specifically for unlawfully possessing a firearm. His sentence has not yet been determined.
The U.S. Attorney’s Office handled the prosecution, while the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) and the Beaverhead County Sheriff’s Office conducted the investigation.
Sepanski now awaits his February 2027 sentencing hearing, when the federal judge will decide the appropriate punishment within the limits established by law.
