Molly Conley, 15, a freshman at Seattle's Bishop Blanchet High School, was walking along a Lake Stevens road with five girlfriends the night of June 1 when she was hit in the neck by a bullet apparently fired from an oncoming car.
Over the next few hours, several other drive-by shootings were reported in the area, with bullets fired into four occupied homes. Although police couldn't find the bullet that killed Conley, ballistics evidence from the other shootings strongly suggested all of the shootings were related, Snohomish County sheriff's detectives said in a probable cause statement released Monday.
A witness to one of the drive-by shootings reported seeing the suspect's vehicle strike a parked car with its front passenger side.
With the help of the State Patrol Crime Lab, detectives learned that the bullets fired in at least some of the other drive-bys were .30 carbine caliber, Detective Brad Pince wrote. Such bullets are less common than .30-caliber bullets, and the markings on the bullets suggested all could have been fired by one weapon, or possibly two.
Investigators then contacted the major sporting goods retailer Cabela's in Tulalip to ask about anyone who might have recently bought a weapon capable of firing .30 carbine caliber ammunition.
On the list, the detective wrote, was Erick N. Walker, of Marysville, who had purchased a Ruger Blackhawk revolver in March and lived within a half-mile of two of the drive-by scenes.
They began investigating Walker and located his car in a Boeing Co. parking lot in Everett. The vehicle had front passenger-side damage, with paint rubbings that appeared to match the damage to the parked car that was struck the night of the shootings, investigators said.
They also noticed his Facebook page, which prominently featured a photograph of two tables lined with guns - including one that appeared to be a Ruger Blackhawk.
Walker was arrested Friday as he drove away from his home. Inside the house, detectives said they found several guns, including two Blackhawk handguns.
He agreed to give a recorded statement to law enforcement, and gave varying accounts of his whereabouts that night, Pince wrote.
According to the detective's account of the interview, Walker initially said that after leaving work, he had two to three beers and two to three whiskeys at a bar in Everett, bought gas in Marysville and drove home. He changed his story to add possible side trips to Clearview, Lake Stevens, Arlington, Monroe and Snohomish.
He also said he might have seen six girls walking along the road in the Lake Stevens area, the detective said.
"Walker stated that if the paint evidence from his vehicle matches the Marysville scene and if any of the recovered bullets are matched to his weapons, he would be the person responsible for committing the crimes. No one else had his car or his guns," the detective wrote.
Walker made his first court appearance Monday, The Herald newspaper reported. His attorney, Mark Mestel, asked for the hearing to be postponed a day to give him more time to review the 20-plus page probable cause statement. Walker was being held without bail.
Conley's family issued a statement asking people not to lose sight of her as they seek to understand why she was killed.
"She inspired classmates, inspired teammates and opponents, and inspired her family to live better lives, to find hope in the midst of hardship, and to play the game - whether soccer, lacrosse, or life - with enthusiasm, determination and joy," the statement said.