Shooting at the Navy Yard, Washington D.C.

Why do only some of these people have their hands in the air? Why do any of  these people have their hands in the air?

Every time I hear about something like this I wonder what was going on. Was this guy really a secret whack job and no one had uncovered his secret? Or was he a social cripple who had endured years of insignificant slights who finally reached his limit? Or was be slowly building his anger from real or imaginary causes? When something like this happens it impossible to backtrack and figure out what led to it. Oh, a skilled and talented investigator might be able to put together a reasonably accurate picture, but since you will be crucified for speaking ill of the dead, we will never hear that story. I think there must be some kind of vile culture at the workplace that reinforces people's natural hatred for others.