WMG / The Fourth Kind

Sheriff August has also seen the owl and is in such angry, fearful denial of what that means that he ignores the video evidence and the testimony of one of his deputies, and insists Dr. Tyler made the whole thing up.
Will didn't commit suicide, the aliens really did kill him because he was getting too close, but made it appear as suicide by gunshot the same way they can make their presence appear as an owl and erase people's memories.