From The Truth About Guns:

“The laws that forbid the carrying of arms are laws of such a nature. They disarm only those who are neither inclined nor determined to commit crimes…. Such laws make things worse for the assaulted and better for the assailants; they serve rather to encourage than to prevent homicides, for an unarmed man may be attacked with greater confidence than an armed man.”
– Thomas Jefferson, Commonplace Book (quoting 18th century criminologist Cesare Beccaria), 1774-1776