Officer Troy Meade originally was charged with first-degree manslaughter in the case, but prosecutors Thursday filed an additional charge of second-degree murder in Snohomish County Superior Court.
A second-degree murder charge means that prosecutors believe the defendant intended to kill the victim, and it carries a higher penalty than a manslaughter conviction.
"The charge is someone has intentionally caused the death of another person," says Chief Prosecutor Joan Cavagnaro.
Meade, 41, is scheduled to go to trial next month in connection with the June 10 shooting death of Niles Meservey of Stanwood. The shooting happened as Meade was trying to get the drunken man out of his car.
Meservey, 51, was shot seven times in the back as he sat at the wheel of his idling white Chevrolet Corvette, boxed in by three police cruisers in the parking lot of Chuckwagon Inn after officers responded to reports of a drunken driver.
Meservey's blood alcohol level was 0.26 - more than three times the legal limit - when Meade shot him in the back multiple times.
Witnesses say the car lurched forward over a parking curb and away from Meade, possibly from an involuntary reflex after Meservey was jolted with a Taser, and lodged against a fence and a parking curb before the officer began shooting.
The 11-year police veteran has pleaded not guilty and has claimed the shooting was in self-defense.
Meade's attorney, meanwhile, calls the increased criminal charges "piling on by the prosecution," and he has asked the judge to throw out the second-degree murder charge.
"I don't think an officer who is on duty - who is sworn to uphold the law - should ever be charged with a crime like that," said the attorney, David Allen.
According to the results of a multi-agency investigation released earlier, another officer overheard Meade cursing at Meservey before shooting him to death.
Meade is also quoted as having said, "Time to end this. Enough is enough."
But Allen claims the statements are mere hearsay.
"Nobody else heard that," he said. "This is from the same officer that didn't help officer Meade when he needed help."
According to an affidavit filed in court, another officer at the scene, Steven Klocker, "told investigators that he perceived no immediate or imminent threat to the defendant (Meade), any civilians or himself when the defendant opened fire."
But Allen claims Officer Meade's life was in danger from a drunken driver who was trying to flee from the scene in his car, and he fired in self-defense.
"He was placed in a situation where he was in back of the car. He would have been crushed if the car moved, after he'd ask the person many many times to get out of the car," said Allen.
Witness Trisha Tribble tells a different story, however.
"No way his car could have been used as a deadly weapon," she said.
Tribble admits Meservey appeared to be drunk and uncooperative with police.
"Yes, he was being difficult, but that's no right for death," she said.