The patrol car was traveling south on 68th street around 12:30 a.m. Sunday morning while an Acura was heading east on 196th, says Sgt. Cindi West.
The intersection is controlled by a traffic signal, and both cars entered the intersection around the same time.
"At this point our deputy said his light was green," Sgt. West said. "One of the passengers in the other vehicle said they had been racing another vehicle prior to the accident."
The details of the crash are under investigation, but evidence shows the patrol car hit the driver's side of the Acura. No indications of drugs or alcohol were noted.
Two passengers from the Acura had minor injuries and were released at the scene. The 17-year-old driver was taken to Harborview in critical condition, and the deputy suffered a broken wrist.
The seven year King County Sheriff's Deputy is assigned to work with Sound Transit, and it is unclear whether he was on a call, headed home, or simply doing an area check-in.
The accident is currently being investigated by the King County Sheriff's Office Major Accident Response and Reconstruction Unit.