Oregon police and FBI officials said militiaman LaVoy Finicum reached for a 9mm semi-automatic handgun before he was shot dead after a high-speed chase.
The FBI has released an aerial-view video of the confrontation.
Finicum, an outspoken member of the Western militants who seized the Malheur National Wildlife Refuge near Burns, Oregon, in a dispute over federal pasture lands, had vowed just days before the shooting: "I"d rather be dead than in a cage." The Arizona rancher was killed after FBI and state police officers stopped him and seven others as they drove in two vehicles to a community meeting beyond the refuge.
The video footage of the confrontation, taken from an FBI plane flying above the traffic stop on 26 January, first shows a Jeep being pulled over by police and its three occupants -- including militia leader Ammon Bundy -- leaving the car. Another militia leader, Ryan Payne, gets out of a white truck — driven by Finicum -- with his hands up. Payne and the three in the Jeep were arrested.
Finicum's white truck is seen racing from the scene at a high speed. The truck appears to plough into a snowbank and Finicum eventually exits. At that point Greg Bretzing, special agent in charge of the FBI in Oregon, said that Finicum "made a movement" and reached his right hand toward a pocket on the left inside portion of his jacket where had a loaded 9mm semi-automatic handgun. Bretzing described the confrontation when the video was shown at a press conference.
Ammon Bundy, who remains in custody, has asked the remaining militants at the refuge to surrender to law enforcement. A handful remain with one predicting a "bloodbath" on a video posted to YouTube. But a later video showed an unidentified militiaman saying: "We want to live. We want to go home peacefully."
Bretzing said officials believe there are four others who remain at the refuge. Since the establishment of new checkpoints after Bundy's arrest, nine people have left the refuge. Of those, the FBI released six and arrested three.
"The negotiators continue to work around the clock to talk to those four people in an effort to get them to come out peacefully," Bretzing said, OregonLive reported.
The occupation began on 2 January and grew to several dozen people, who demanded that the federal government turn public lands over to local ranchers. But the compound has been emptying out since Finicum's death and Bundy's arrest.