The Sherman County District Attorney has ruled that Oregon State Police Trooper Matt Zistel acted in self-defense when he shot and killed motorist John Van Allen II of East Portland on Aug. 29 on Interstate 84 near Rufus, according to information released Sept. 17.

The incident occurred at around 12:50 p.m., when Zistel initiated a traffic stop of a Cadillac Catera for traveling at 76 mph in a construction zone. The vehicle pulled to the side of the road and Zistel pulled his patrol car behind the suspect’s vehicle.