I do not take this to mean that any arrested development case with a couple of hundred bucks and an itchy trigger finger should be allowed to carry, or even own, a gun.
I do believe it is the duty, right and privilege of every responsible citizen who knows and obeys the law to be prepared and able to defend that law. No responsible gun owner would use his gun to arrest his neighbor for double parking. On the other hand, such a gun owner should never have reason to hesitate to use that gun to interrupt or stop a robbery, mugging, rape, or other violent crime in progress. The militia is always present, even when a professional policeman is nowhere to be found.