The Second Amendment does not include the right to "keep and bear" military-style assault weapons with large magazines, such as an AK-47, an AR-15, or a MAC-10. A society that allows unregulated availability of assault weapons creates a situation in which anyone can easily obtain such weapons. We have seen too many times already that mass murder in a school or a crowded theater or a shopping mall produces tragic slaughter of innocents. Such mass murders cannot be done so easily without the assault weapons.
Punishing the criminal later cannot undo the damage or restore the dead to life. The damage is huge and permanent. The victims' suffering ends with their deaths; but the surviving families can never be made whole. Their suffering is long and deep.
The original intent of the Founders was based on the firearms technology of that era. Let's accept that the Second Amendment applies only to single-shot, muzzle-loading flintlock firearms as the Founders intended. There will be less trouble that way.