GORST, Wash. (AP) — A 26-year-old man pleaded not guilty to a murder charge on Wednesday in connection with a road-rage shooting Monday in Washington state.

Mark Keith Smith of Burien was initially charged with assault in Kitsap County Superior Court after the confrontation west of Seattle in Gorst. Prosecutors filed a second-degree murder charge against Smith on Wednesday after 68-year-old Patrick Weems died at a hospital. Smith pleaded not guilty Wednesday, and his bail remains set at $1 million, The Kitsap Sun reported.

Efforts to reach a lawyer for Smith weren’t immediately successful. Smith is claiming self-defense, KING-TV reported.

Washington State Patrol officials say the shooting stemmed from interactions between the men while driving on Interstate 5 before both exited onto state Route 16.

Witnesses told investigators that they saw both men pull over their vehicles in Gorst and that Weems got out of his vehicle with a bat in hand and Smith got out with a gun, according to state police. The confrontation ended with Smith shooting at Weems, according to state police. Smith then left the scene and was arrested several miles south.

Smith told investigators that Weems had attempted to run him off the road multiple times, according to state police.