(Salem, OR) -- A Marion County grand jury has found an Oregon State Police trooper was justified in the fatal shooting of a man at an Oregon National Guard facility in Salem. Prosecutors say Matthew Wong approached a guard station and handed the guard a threatening note and walked away. Trooper Justin Oxenrider approached Wong, who refused to drop a knife. Oxenrider tried using a taser twice, which didn't work. When Wong aggressively approached Oxenrider he fired two shots killing Wong. The grand jury determined deadly force was justified.