It's the first-known marijuana DUI since I-502 went into effect.

47-year-old Scotty R. Rowles was arrested in Vancouver, Washington Monday evening after he allegedly struck a pedestrian with a vehicle and killed him. Police said Rowles was questioned and examined by a drug recognition expert at the scene. He was taken into custody after it was determined he was under the influence of marijuana.

The victim, 62-year-old Donald L. Collins, reportedly stepped off a median and into the street near East Mill Plain Boulevard and Andresen Road in Vancouver shortly before 6 p.m. According to reports, Rowles cooperated with authorities.

This fatality comes just a few weeks after marijuana was legalized in Washington state by I-502. The law allows possession by adults of up to one ounce of the drug. Authorities are going to be facing a new set of driving infraction procedures to deal with marijuana-affected drivers, including a possible driving-while-stoned charge that could be added to criminal offenses.