The driver of one vehicle suffered a gunshot wound to the shoulder during the chase, and his sister told KOMO News the shooting was gang-related.
The bizarre drama began at about 4 p.m. when some men made eye contact with the man who was later shot made at a festival in Seward Park, said Jeff Kappel of the Seattle police.
Preliminary investigation indicates that the two parties exchanged glances at the park, Kappel said. The 20-year-old victim, who was with his 17-year-old nephew, then went to park his blue Chevy Suburban on a neighborhood street outside the park.
On the way, the victim noticed the suspects he had seen in the park following him in a gray or green car. The victim then tried to lose the suspects by driving through the neighborhood, and a chase ensued.
The suspects started shooting at the victim in the 9000 block of Beacon Avenue South. The chase continued and more shots were fired at Beacon Avenue South and South Juneau Street, police say.
It's believed more shots were fired by the suspects at South Columbian Way and South Spokane Street.
The chase continued onto the southbound lanes of I-5, Kappel said.
The victim was driving in the car pool lane when the suspects pulled up alongside the victim at about mid-Boeing Field. The suspects continued shooting at the victim, striking him in the shoulder.
At about that time, the shooting's car collided with a silver Kia 2-door occupied by a 43-year-old woman and her 14-year-old daughter who were not involved in the incident.
The Kia driver lost control, struck another motorist in a Toyota, and flipped over. The occupant of the Toyota was not injured.
Meanwhile, the shooting victim's Suburban came to rest alongside the cement divider on I-5 South. Kappel originally said it was the shooting victim's car that collided with the Kia, but the Washington State Patrol, which is handling the crash investigation, now says it was the shooter's car that struck the Kia.
Medics responded to the scene and transported the 20-year-old shooting victim and the two people from the Kia to Harborview Medical Center with non-life-threatening injuries. The two from the Kia were released late Sunday.
The shooting victim's nephew, who was in the Suburban with him throughout the ordeal, was not injured.
Victim's sister says shooting was gang related
The sister of the victim shot in the shoulder says her brother used to associate with the Crips many years ago before moving away and turning his life around.
"He gang-banged like 6, 7 years ago," says Mari, who didn't want to give her last name. "And he's 20 now."
She says men from a rival gang were following him in two cars.
"Maybe 3 or 4 (people) in each car and they were all wearing red -- does that stand for anything?? Blood.... Bloods, yeah," she said. "So you have the Bloods and you have the Crips."
Now she worries the old ties will still come back to haunt her brother.
"They want him dead," she said.
Another innocent motorist who was driving southbound on I-5 got his windows shot out by a stray bullet fired by the suspects. That driver drove home to the West Seattle area and called 911. An officer responded and documented the property damage. The driver was not injured.
Officers also discovered a parked car in the 5900 block of Beacon Avenue South with damage from gunfire.
The suspects and the suspect's vehicle remain at large.
Washington State Patrol troopers and Seattle Police Gang Unit detectives will be handling the active and on-going investigation.