An elaborate computer analysis, a review of the FBI aerial video of the shooting scene and a video from a passenger in Finicum's pickup produced a result that startled the team poring over evidence into Finicum's fatal shooting that day.
The fourth round, police concluded, was fired by an FBI agent who subsequently twice denied to investigators ever firing his gun. As the investigation proceeded, detectives determined he also fired a second time, but didn't hit anything at the scene.
http://www.oregonlive.com/oregon-standoff/2016/03/oregon_standoff_fbi_lie_uncove.html#incart_maj-story-1