Which would you guess was true?

San Francisco police shot and killed a man last night.

http://www.ktvu.com/video/28575181/index.html

The man was running away.  If you didn’t know the facts, would you think it is more likely that the police shot an unarmed man for no reason or that they shot an armed man who was shooting over his back at them as he ran?  People who know no more of the facts than you or I do believed the first and took to the streets to scream that the police were murderers.  Who are these people?  And what twisted view of reality would lead them to jump to that assumption?