The suspect, who hasn't been named, is a 41-year-old Tulalip resident, according to deputies. He was booked into the Snohomish County Jail on Wednesday for murder in the 2nd degree, drive-by shooting, and rioting.
Ryan Mumm died on Sunday, a day after deputies found him with a gunshot wound to the head in Blue Stilly Park in north Snohomish County.
Deputies responded to the scene at about 8:30 p.m. on Saturday after receiving reports of a shooting, said Lt. Stephen Dittoe of the Snohomish County Sheriff's Office.
Mumm was treated at the scene before being rushed to Providence Hospital in Everett.
During the course of the investigation, deputies found a car at a local gas station that may be related to the shooting.