Violent criminals don't attack the strong or the armed, they prefer weak and unarmed victims as a general rule and the criminals attacking other criminals are often illegally armed where the average man at home, on the street or in his place of business is by law defenseless.
Man has a right and a duty to defend themselves. It is impractical for them to carry a policeman around in their back pack wherever they go. Unless that happens restrictive gun laws are unreasonable.
Want to reduce the number of violent felons. Let society be armed, be polite and watch the violence decrease. Dead or severely wounded boogermen who just got ventilated by an 77 year old great grandmother watching over her family are unlikely to repeat bad behavior. Especially the unlucky ones who got themselves turned into room temperature.
Save the prison space for the really evil people. White collar criminals responsible for millions in losses and unrepentant sex offenders of all flavors. The violent boogermen will either modify their bad behavior or get themselves taken out of the gene pool.