The Kneecapper

The Kneecapper is a unique Sawed-Off Shotgun, featuring increased damage and tighter spread.

Location

 * It can be obtained from Ronald Laren from Girdershade.
 * It can also be obtained in the quest The Waters of Life. After your father is killed adjust your view and try to search his dead body from across locked door.

Obtaining the gun from Ronald Laren

 * By far the easiest way without killing Ronald is to pickpocket his shotgun ammo, shoot him once, holster your weapon and pickpocket The Kneecapper once he turns friendly again.
 * When talking Ronald into venturing for Quantums on his own (Black Widow Perk required) he usually dies on the way and his corpse can be looted near or in the Nuka-Cola Plant.
 * Pickpocketing Ronald's shotgun ammunition, and then leaving, saving, reloading and returning to the area will cause his weapon to appear in his inventory, making it possible to steal without any violence and only minimal karma loss.
 * You can also wait until he goes to bed and pickpocket the Kneecapper while he sleeps.
 * It's actually relatively easy to get this weapon without killing Ronald. Attack him with a weak weapon (so that you don't kill him), then shoot the gun from his hands.  Put the weapon away and he will stop attacking you (he will fight with his fists otherwise).  Now use the grab button to move the gun so that you can take it while he's not facing you, then just take it.  This counts as a theft and thus carries a small karma loss, but the loss is much less than killing him for the weapon, and as long as he doesn't see you while you're taking it, he won't become hostile again.
 * One easy method is to fight or lure Ronald outside and then draw him towards some of the roaming beasts in the area.(There are many nasty critters by Girdershade, including Giant Radscorpions and Deathclaws. Let them get close, and then use a Dart on Ronald to make sure that all goes to plan.) This should work without even the smallest Karma kick.
 * One more way, anytime there is someone you must kill to acquire an item, (in this case you don't have to, but if you want to) but killing them will result in negative karma, simply bring a follower with you and attack the target unarmed or in the leg with your pistol. The target character will become hostile, causing your follower to kill them so that you don't get any negative karma. (This has been tested, except I caused Jericho to clear out the entire lobby floor of Tenpenny Tower, then looted the shopkeepers for their inventory keys.)
 * Additionally with a little luck the mysterious stranger perk can be used here. Just target the kneecapper in VATS and if you luck out the stranger will come in and kill Ronald for you with zero karma affect.
 * Or just kill him and don't worry about the Karma. Unless you are routinely killing good guys and/or stealing a lot of their stuff, your Karma will probably be high enough that killing him will not even change your Karma rank.
 * Using the Mr. Sandman perk allows you to kill Ronald while he is sleeping and, as well as gaining good xp, Sierra Petrovita doesn't notice he's dead. This method does not induce a karma loss as the mister sandman perk does not affect karma

Trivia
The Kneecapper may take its name as a reference to Once Upon A Time In Mexico, where the hero, El Mariachi, blows off the knees of his enemy with a single sawed-off shotgun blast. Also in the film Terminator 2 John Connor forbids the T-800 from killing anyone. In response during their escape of the mental facility, he shoots any hostiles between them and the exit in the kneecaps, debilitating them without killing them. This weapon might also be a reference to Mad Max, in which the protagonist was shot through the kneecap.

YouTube videos
thumb|500px|left|Obtaining The Kneecapper

=Weapons Lists=