NEW WESTMINSTER - An Alberta man shot and killed the Abbotsford, B.C. police constable who died in the line of duty in 2017, a judge ruled Thursday, but she has not yet determined whether he'll be held criminally responsible.

In her ruling, Justice Carol Ross said the Crown proved its case that 67-year-old Oscar Arfmann murdered 53-year-old Const. John Davidson, but the verdict, which she pronounced as “guilty of first-degree murder” will not be entered into the record, pending a psychiatric assessment and court hearing next year.

“We all felt heavy,” said Chief Const. Mike Serr of the Abbotsford Police Department about the moment the judge read her verdict.

“Is this justice for Const. Davidson?” CTV News Vancouver asked.

“I don’t know if there’s ever justice,” Serr responded. “I’m pissed off. I lost a very good police officer. And the city lost a very good man.”

Davidson's widow and three adult children were in the front row of the public gallery when the judge read the verdict Thursday. At least two dozen uniformed and plainclothes officers were also in court to hear the decision.

The courtroom was silent after the judge announced the verdict. Officers could be seen reaching for tissues to dab at their eyes.

CTV News covered the verdict live from court. Scroll down to read through our live blog.

“John’s murderer ambushed John,” Serr said. “He shot John in the back, and as he lay on the sidewalk, he executed john. And that’s not the person I want to remember in this.”

Arfmann had pleaded not guilty and did not visibly react to the verdict.

After her decision, the judge reference an existing psychiatric assessment that said Arfmann was suffering from schizophrenia on the day of the murder, and said he’s still dealing with the illness.

That assessment, the judge said, was inconclusive on whether Arfmann would have been capable of understanding his actions the day of the shooting.

His lawyer, Martin Peters, called the judge’s verdict a “good decision” that “reviewed the evidence very carefully.” He said Arfmann understands the verdict, even though he may “have his own views.” Peters said he is unlikely to appeal.

“Do you believe your client knew right from wrong when he shot and killed Const. John Davidson?” CTV News asked Peters.

“I don’t know the answer to that question,” Peters said. “I don’t have a belief one way or the other.”

At Peters' request, the judge decided to grant a new psychiatric assessment, which will be completed later this year.

In February, both sides will return to court for what’s known as an "NCR hearing," to determine whether Arfmann’s mental state on Nov. 9, 2017, will result in him being declared “not criminally responsible.”

If that were to happen, an independent review board would determine whether Arfmann would be transferred to hospital or released with or without conditions. If Arfmann is found criminally responsible, the automatic sentence for first-degree murder is life in prison.

Davidson was shot and killed in a shopping centre parking lot on Mount Lehman Road after someone called 911 to report a stolen vehicle. He was shot twice from behind. The 24-year policing veteran, originally from the UK, died within seconds.

Police later chased Arfmann in a black Ford Mustang down Mount Lehman Road and rammed his vehicle. When they pulled him from the car, they found what the judge said was proven to be the murder weapon on the passenger seat.

“Nothing will bring John back,” Abbotsford Chief Const. Serr said, as he thanked investigators, prosecutors and the witnesses who ran to Davidson so he wouldn’t be alone when he died. “Nothing will fill that void for his family, or for any of us.”

With files from The Canadian Press, and CTV News Vancouver's Sheila Scott