The video release came after protest leader Ammon Bundy repeated a call for the last four holdouts to peacefully leave the Malheur National Wildlife Refuge to avoid more bloodshed.
Eleven people including Bundy have been arrested since Tuesday, when Robert "LaVoy" Finicum -- the movement's de facto spokesman -- was shot dead near the town of Burns in a bloody twist to the drawn-out standoff with the federal government.
The video was shot from an FBI plane overlooking a highway on which two vehicles, one of which Finicum was driving, were traveling.
"I want to caution you that the video does show the shooting death of LaVoy Finicum," Bretzing told a media conference.
"We realize that viewing that piece of the video will be upsetting to some people, but we feel that it is necessary to show the whole thing unedited in the interest of transparency."
The second vehicle, Finicum's white truck, carries on with officials in pursuit.
A few minutes later one man gets out and gives himself up, but Finicum refuses to surrender and drives off again at speed and approaches a road block, before swerving, nearly hitting an FBI agent and getting stuck in a snowbank.
"Finicum leaves the truck and steps through the snow. Agents and troopers on scene had information that Finicum and others would be armed," said Bretzing.
"At this time, OSP (state) troopers shot Finicum."
Three remaining people in the truck, including Bundy's 43-year-old brother Ryan, were taken into custody and officials then gave medical help to Finicum.
"That happened about 10 minutes after the shooting," said Bretzing, adding that they found three loaded weapons in the truck, including two semi-automatic rifles.
