Not a helpless bystander

In Tyler, Texas, a man came to the courthouse to kill his ex-wife, his son, and anyone else who got in his way. Mark Wilson saw what was happening and intervened. (He was a CCW holder.) He was killed but authorities believe that his action saved the son's life.

The murderer broke off his attack and escaped in his truck. A few minutes later he was shot by police.

First, let me say that Mark Wilson is a hero. He saw trouble and did not run away from it. He ran to it and tried to stop it. His sacrifice saved lives.

Second, I think this shows that immediate civilian response can completely change the dynamic of a mass shooting. (A point discussed at length here with regard to Richard Clarke's views on future terrorism.)

Third, the killer wore body armor just as in Tom Maguire's nightmare scenario. Yet that protection only let him extend his spree by a few minutes.