A Mountie in B.C.'s West Kootenay region has been charged with manslaughter in the fatal shooting of a father of four during an attempted traffic stop in January 2015.

Const. Jason Tait was officially charged on Tuesday, even though the Independent Investigations Office (IIO) wrapped up its investigation and issued a report on the shooting in December 2016, according to the B.C. Prosecution Service.

"The investigation and charge assessment process were protracted due, in part, to the complexities of the evidentiary issues in the case and the requirement for further investigation and analysis," a statement from the service said.

Tait was a member of an RCMP traffic unit at the time Waylon Edey, from Yahk, was shot near Castlegar. The officer had gone to the area after police received a call about an impaired driver on Highway 3.

Edey's mother, Deborah, told CBC News that she was satisfied with the charge.

"I was very happy. I think his kids were very happy," she said Tuesday. "It has been a long three years, so we'll take what we can get."

(Deborah Edey)

Lawsuit filed in Supreme Court

Allegations about what happened on the night of the shooting are outlined in documents filed in civil proceedings in B.C. Supreme Court.

Deborah Edey filed suit in December 2016 on behalf of her grandchildren, who range in age from 12 to 22. She alleges her son was unarmed at the time he was shot and that the use of deadly force was unwarranted.

Those named in the suit include the province's minister of public safety and Canada's attorney general, as well as the RCMP officer who shot Edey, who is referred to as John Doe in the civil claim.

In a response to the civil claim, filed in April 2017, the defendants say that the incident began after RCMP received a report of an impaired motorist driving a pickup truck through the drive-thru of a local restaurant.

A Mountie has been charged with manslaughter in the shooting death of Waylon Edey, from Yahk, B.C. (CBC)

It alleges an RCMP officer drove his police vehicle past Edey and stopped in the westbound lane of Highway 3 outside Castlegar.

"Once the RCMP member stopped his police vehicle, he stepped out of his vehicle, got out on foot onto the eastbound portion of Highway 3 and motioned for the driver of the suspect vehicle to stop," the document says.

"The suspect vehicle continued to drive towards the RCMP member as the RCMP member was attempting to stop the suspect vehicle."

The claim alleges Edey's truck struck the police cruiser and then continued toward the officer.

"The RCMP member discharged his service pistol once at the driver of the suspect vehicle while the suspect vehicle was in the eastbound lane of Highway 3," the claim says.

The response to the civil claim maintains the officer was justified in defending himself and members of the public from harm.

None of the allegations in the lawsuit have been tested in court. No monetary damages were specified.

Tait is scheduled to make his first appearance in provincial court on the manslaughter charge on April 30.