How? Ann Coulter explains how HERE. Basically, all that is needed is…
…the presence of someone with a gun at hand. Says Coulter, “If what we care about is saving the lives of innocent human beings by reducing the number of mass public shootings and the deaths they cause, only one policy has ever been shown to work: concealed-carry laws. On the other hand, if what we care about is self-indulgent grandstanding, and to hell with dozens of innocent children being murdered in cold blood, try the other policies.”
What policies? “Gun-free zones,” gun bans, passing “gun control” laws, creating trade-in programs, etc. All are dreamed up by Regressives (don’t call them “Progressives”; nothing about them is related to “progress”). All are useless, and very often counterproductive, as Coulter explained.