HALIFAX - An RCMP officer entered the home of a potentially suicidal man on a Nova Scotia reserve moments before he shot him because he thought he could retrieve the man's rifle, says the lead investigator of the probe into the 2008 fatal police shooting.

Halifax police Supt. Michael Burns explained the officer's rationale for entering John Simon's residence during a briefing he gave to the Wagmatcook First Nation's band council and Simon's family.

A recording of the Monday briefing was provided to The Canadian Press on Thursday by Gary Richard, the band council's lawyer.

Richard said he put his tape recorder in plain view of the officers during the briefing.

At one point during the meeting, Richard asks Burns why the officer went into Simon's home through an open window during the Dec. 2, 2008, encounter.

"He felt that he could, from his past dealings with Mr. Simon ... retrieve the firearm," Burns said on the recording.

To date, the RCMP have declined to make public the reasons why the officer decided to enter Simon's house, citing privacy legislation.

The investigation into the fatal shooting, led by the Halifax police, has concluded that the officer didn't violate any laws and shot Simon in self-defence.

The recording also gives a more detailed account of what investigators say occurred before Simon's death.

The RCMP did not return a message late Thursday seeking comment about the recording.

Burns said the Baddeck, N.S., RCMP detachment responded to a 911 call, adding that there was a reported dispute at Simon's residence, that he was drunk, possibly suicidal and had access to firearms.

Two constables and a supervisor arrived at the house and secured the area, Burns said.

One of the constables moved closer to Simon's home, onto the deck, and saw Simon through an open window, Burns said.

"After a brief discussion, he moved back onto the deck to an open window where he observed Mr. Simon going to the bathroom ... unarmed," said Burns.

At that point on the 70-minute recording, a family member asked the constable's supervisor -- who was also present at the meeting -- if he had ordered the officer to enter Simon's home.

"No, I did not," the supervisor said.

Burns said after the constable entered Simon's home through an open window, he identified himself and ordered Simon to lie on the ground.

"Mr. Simon failed to comply with his command and turned toward another area of the residence away from the police officer," Burns said.

"The constable ... was subsequently confronted with Mr. Simon, who was in possession of a rifle."

"Being confronted with a rifle, the police officer discharged his service pistol three times at Mr. Simon, with the last discharge having stopped the threatening behaviour."

Simon was taken to a nearby hospital where he died.

Earlier in the day, RCMP Chief Supt. Blair McKnight said the force will review their training policies for responding to "critical incidents" like suicides.

During his briefing Monday, Burns said he concluded there is significant evidence to back the decision not to lay criminal charges against the officer.

"There's been a significant forensic examination of the police officer's service pistol and Mr. Simon's rifle," Burns said.

"Forensic laboratory results lead to the inference that the gun was pointed at (the) constable ... at the time he shot Mr. John Simon."

Burns's conclusion triggered an angry outburst from frustrated relatives, who can be heard on the tape swearing several times and repeatedly demanding the release of the report into Simon's death.

Brian Arbuthnot, the band administrator, said Thursday that the explanations given to the band aren't satisfactory and he wants to know if the reasons for entering Simon's home were justified.

The band will meet with Nova Scotia Justice Minister Ross Landry on Jan. 19 to ask him to launch a public inquiry into Simon's death.

"This is a totally disrespectful way of treating a family and a community," Arbuthnot said.

The band has been told it can apply for the full investigation report under the access-to-information legislation, but Arbuthnot said he fears key details will be blacked out.