Yeah, that was pretty sad, never knew the whole story, but I found this:
Evans was shot and killed by the police on 5 January 1976, in his rented duplex at 8122 W. 4th Street in Los Angeles. The officers mistakenly believed that the air pistol Evans was holding was a rifle. Before his death Evans was working on a book of memoirs called Living The Beatles' Legend, which he was supposed to deliver to publishers Grosset and Dunlap on 12 January 1976. Friends said that Evans was depressed about his separation from his wife Lil Evans