Don Dunphy, who was shot and killed by a member of Newfoundland and Labrador Premier Paul Davis's security detail, aimed a loaded rifle at the officer prior to being fatally shot Sunday afternoon, RCMP say.

According to the Mounties, the Royal Newfoundland Constabulary officer was invited into Dunphy's home when he arrived last weekend in Mitchells Brook, N.L., to investigate what was perceived to be a threat made against the premier and another politician.

Don Dunphy in 2011

The RCMP said Tuesday that Don Dunphy, pictured here in an interview with CBC, aimed a loaded rifle at a Royal Newfoundland Constabulary officer before Dunphy was fatally shot Sunday afternoon. (CBC)

A 15-minute conversation occurred when there was a "sudden and dramatic" change in the demeanour of the visit, the RCMP said in a statement Tuesday.

At that point, RCMP said, Dunphy aimed a long-barrel firearm at the officer.

RCMP said evidence indicates the RNC officer responded with lethal force. Dunphy died at the scene.

A .22-calibre rifle was found on the floor of Dunphy's home, about 85 kilometres southwest of St. John's. During a forensic investigation, it was determined the gun was loaded.

No word on how many shots fired

Speaking to reporters Tuesday afternoon, RCMP Sgt. Greg Hicks didn't specify whether Dunphy fired the gun, nor did he comment on how many shots were fired, adding that would be determined in the course of the investigation.

Hicks said there was no indication of what prompted the change in demeanour during Dunphy's conversation with the RNC officer.

"The specifics as to what occurred during those final moments are still a matter to be processed," he said.

Hicks wouldn't confirm whether the RNC officer acted by the book during the incident, adding that would be a part of the RCMP investigation.

"There were no witnesses to this incident, so [the investigation] was be relying heavily on the forensic evidence."

Any decisions surrounding charges will be made once the investigation is complete.

No perceived risk

According to RCMP, the RNC officer conducted a routine "risk assessment" before making the trip to Mitchells Brook to investigate the perceived threat made against Davis and MHA Sandy Collins.

However, the officer determined it was a "low-risk" situation and it wasn't necessary to bring along a second officer. The RCMP Holyrood detachment, which polices the rural area, was contacted prior to the visit.

Dunphy's Twitter account had been deactivated since Monday, but Hicks said that to his knowledge, the RCMP wasn't involved in shutting the account down.

Members of the RCMP, along with the RNC, make up the premier's security detail, but Hicks said there is no conflict of interest in having the RCMP investigate the fatal shooting because it was an RNC officer involved.

RCMP said its investigation is ongoing.