After every spree shooting, like the one that just happened in Florida at a School Board meeting, everyone wants to play amateur psychologist and find what the gunman's motivations was.
Here is the answer regardless.
He woke up and decided to be an evil bastard with a gun.
When you encounter an individual whose desire is violence, death and destruction you must meet him on equal terms. While it may seem brave for a man to try and lovingly talk a gunman into laying down his gun and save his life or for an old woman to swing her purse at a gunman it simply is not appropriate.
If you have a gun you shoot him, if you have a knife you make a strategic move to get behind him if you can and put the knife into the back of his skull or kidneys. If all you have is a fire extinguisher you blind him with the spray get out of the path of blind fire and use the canister to bludgeon him to death and leave his head a bloody pulp on the linoleum.
While it may sounds gruesome it is not as bad as a friend, a father, a mother, a husband or a wife not coming home.
Lying on the ground while a gunman walks around shooting people is never ever ever the right thing to do regardless what any police chief says at a press conference. Killing the son of a bitch is.