Kalispell man found guilty of deliberately killing man with his car

A Kalispell man was found guilty last week of deliberately killing a pedestrian by hitting him with his car last August.

Jeffrey Serio, 48, appeared for a week-long trial before Judge Heidi Ulbricht in Flathead County District Court starting May 6. On May 13, after around six hours of deliberation, the jury returned a guilty verdict on one charge of deliberate homicide in the death of Raymond Grigg, according to prosecutor Ashley Frechette with the Flathead County Attorney’s Office.

According to court documents, on Aug. 19, 2025, deputies with the Flathead County Sheriff’s Office responded to reports of a suspicious man on a property in Kalispell near the Glacier Park International Airport. A deputy arrived to find Serio on the scene, who said his vehicle was parked nearby. After being told to leave the property, Serio did so, leaving for his parked vehicle.

While leaving, documents state, the deputy heard what sounded like a rapidly accelerating car driving through a nearby cornfield, then saw the car driving through a fence. The deputy then heard gunshots.

More deputies responded immediately and found Grigg trapped underneath Serio’s vehicle. Witnesses stated Serio was driving toward Grigg’s house through the neighboring field, that they’d heard gunshots, and that Serio had gotten out of the vehicle and left the scene. Serio was found soon after. In charging documents, no witness reports directly seeing the collision between Serio's vehicle and Grigg.

Law enforcement located five shell casings at the scene. Two rounds had hit the front of Serio’s car.

The primary goal of the prosecution was proving that Serio was the aggressor, Frechette said, because this was a self-defense case. Grigg had fired several shots at Serio's car, she said. The defense argued that Serio had driven at Grigg to defend himself against the shots, while the state argued that Grigg fired at Serio because Serio was driving toward him, Frechette said.

The Missoulian reached out to Serio's defense attorney, Alisha Rapkoch, with questions on Monday but had not yet received responses.

Sentencing is set for July 26. Deliberate homicide carries a possible sentence of 10-100 years in prison or life in prison.