Four of the suspects were juveniles, according to police. One of the suspects intentionally rammed an occupied K9 vehicle during an altercation.
Two people were treated on scene but declined further medical care, Seattle Fire Department says.
The incident occurred near Beverly, downing power lines and causing a small wildfire.
The detective said Seattle is a hub for commercial sex in the Northwest.
The officer was traveling at 74 miles per hour in a 25 mph zone just before his police cruiser hit Jaahnavi Kandula in January.