The incident unfolded at about 8:45 p.m. when officers were called to the area of 31500 1st Avenue South in Federal Way after receiving a report of gunshots fired, said Cathy Schrock of the Federal Way police.
Officers arrived on scene, but were not able initially to locate any disturbance or evidence of a crime.
About 10 minutes later, authorities were notified that an 18-year-old victim had been dropped off at St. Francis Hospital in Federal Way with gunshot wounds. The victim did not survive.
Officers questioned the victim's brother, who had brought him to the hospital.
Initially, police had no suspects and were not sure exactly where the shooting had taken place. But after working through the night, detectives were able to identify three suspects.
Early Friday morning, Federal Way police and the Valley SWAT Team served search warrants in the 5600 block of South I Street in Tacoma, where the suspects - a woman and two men - were apprehended. Two of these suspects are cooperating with detectives, Schrock said.
The identity of the victim was not immediately released.
Anyone with information about the shooting is asked to contact the Federal Way Criminal Investigations Section (CIS) at 253-835-6780.