EVERETT — A jury likely will begin deliberations later this week in the trial of a Marysville man accused of killing 15-year-old Molly Conley.

Snohomish County deputy prosecutors on Tuesday called their last witness, a firearms expert with the Washington State Patrol crime lab. Brian Smelser testified that bullets recovered at several homes and cars in Lake Stevens and Marysville were a match for the two Ruger Blackhawk revolvers seized from Erick Walker.

Smelser also told the jury that without a bullet he cannot say what kind of gun was used to kill Molly, a freshman at Seattle’s Bishop Blanchet High School.

Molly was walking with friends along S. Lake Stevens Road on June 1, 2013 when she was struck in the neck by a single bullet. Detectives spent several days over several months searching the road, underbrush, lawns and trees for the bullet but were unable to locate it.

Walker’s defense team on Tuesday again asked Snohomish County Superior Court Judge Thomas Wynne to throw out the first-degree murder charge. Everett defense attorney Mark Mestel renewed his argument that there is no evidence that directly connects Walker to Molly’s death.

The judge denied the motion, saying there was nothing presented at trial to change his previous ruling that a jury should decide the case.

Wynne pointed to the ballistic reports, Walker’s statement to detectives that he had been driving around Lake Stevens the night Molly was killed and a home surveillance video showing a car similar to Walker’s Pontiac about five blocks from the shooting scene.

The defense team later on Tuesday called two witnesses who offered testimony about bullet trajectory and forensic cellphone analysis.

Verne Hoyer, a former police officer, told jurors that there is no way to determine where the shot originated. There are too many unknowns, including the direction Molly was facing when she was struck, he said.

“You can’t pinpoint one location,” Hoyer said.

Hoyer was called to cast doubt on the reenactment that investigators created a few months after the killing. Jurors had seen photographs of a detective pointing a gun out a window at someone portraying Molly.

In cross examination, Hoyer conceded that it is possible that the shot came from a car in the roadway.

Diana Hefley: 425-339-3463, hefley@heraldnet.com. Twitter: @dianahefley