Charges have now been laid in the killing of an Abbotsford police officer on Monday.

Oscar Arfmann, 65, has been charged with the first degree murder of Abbotsford Police Const. John Davidson. Under the Canadian Criminal Code, the killing of a peace officer is automatically a first degree murder charge.

Arfmann, who is from Alberta, was injured in the takedown and taken to hospital. He is expected to survive.

Davidson was killed while trying to arrest a suspect, who had opened fire in the parking lot of a shopping centre in the 3200 block of Mt. Lehman Road on Monday, just before noon.

IHIT appealing to public for help

Cpl. Frank Jang with the Integrated Homicide Investigation Team (IHIT) said that Arfmann has no criminal record. He also did not have a valid driver's licence.

Jang said he had previously obtained a firearms licence, but it expired in 2015.

IHIT is now appealing to the public for photos and videos taken during the incident, as well as information about Arfmann's movements in the days leading up to the events.

"One of our priorities is to learn as much as we can about Mr. Arfmann, what he was doing in Abbotsford, what he was doing in Alberta," said Jang.

"Any friends, any associates ... if you knew Mr. Arfmann, please come speak with our investigators."

Jang declined to comment on the nature of Arfmann's injuries but said he is conscious and under police guard in hospital.

Arfmann is scheduled to appear in court Nov. 28.

Suspect struggled with mental illness, family says

Arfmann's family provided CBC News with a statement, offering condolences to the Abbotsford Police Department and Davidson's family.

Family members said Arfmann hadn't been the same since his wife died in 2013.

"He has been struggling with mental illness and the family members have tried to get him help, but he refused to do so," the family said.

Arfmann had been admitted to hospital in St. Paul, Alberta for a mental evaluation in 2015 but was released three days later after doctors determined nothing was seriously wrong, according to the statement.

He family said he had recently sold his property in St. Paul and purchased a motorhome, with plans to spend time in B.C.

Shots fired in parking lot

Police say the violence began at about 11:35 a.m., when a witness called 911 to report a possible stolen vehicle. The caller then used their car to block in the vehicle.

A man then stepped out of the blocked-in vehicle with a shotgun and began firing at the caller and other witnesses. When police arrived, they returned fire. During the exchange of gunfire, Davidson was shot.

The suspect fled the scene in a car but was arrested after more shots were fired at the intersection of Mt. Lehman Road and Fraser Highway.

Const. John Davidson was killed in the line of duty in November, 2017. (Abbotsford Police Department)

'We have lost John'

In an emotional news conference on Tuesday, Abbotsford Chief Const. Bob Rich paid tribute to his fallen colleague.

"Davidson was the first person in. And he died protecting you and me," Rich said.

"We have lost John, and nothing can change that. We honour John by looking after his family. We honour John by looking out for each other. We honour John by protecting this community."

Anyone with information about Arfmann is asked to call IHIT at 1-877-551-4448 or Crime Stoppers at 1-877-222-8477.