Shotgun. When they bring eight or nine of their friends along to help. When they start by running somebody down with a car. The action needs to be premeditated for them to carry it off successfully. If they are within grabbing distance and they don’t have the advantage of some kind of weapon (a gun), they’re pretty screwed. It’s important to remember that while most trained combatants can stop a crowbar and they can definitely stop a baseball bat (weight distribution on the baseball bat makes it very easy to block), they’ll have a hard time stopping a bullet. This is actually part of the reason why some self-defense experts suggest keeping a gun in the home in the case of home invasion.
Anyway the break down is: numbers and superior force (gun or car or something similar). In the case of a medieval era, a horse will work if your character knows how to ride.