Contract Killer

Contract Killer is a Fallout 3 Perk.

Once you have the Contract Killer perk, any good character you kill will have an ear on their corpse. This ear can then be sold to a certain person (whose identity is disclosed when you take the perk) for caps and negative Karma.

The "certain person"

 * You will get a note from Littlehorn and Associates telling you to go to Scrapyard.
 * Littlehorn & Associates resides at the Scrapyard Office, and will pay 15 caps per ear.

Bounties
With this perk, the player can remove an ear from every Good human or non-feral ghoul character he or she kills. The ear can then be sold to Daniel Littlehorn at the Scrapyard for 15 caps and a Karma decrease.

Bugs

 * The note you receive indicates that you need to go to the east end of the Scrapyard, but you must actually go to the south end.
 * (Happened once on the Xbox 360) If you shoot Daniel Littlehorn with a Dart Gun and then have the luck of knocking him unconscious as he is "phasing" through the door outside to the Scrapyard, when you go outside Daniel Littlehorn will be nowhere in sight. When you go back into the building, Daniel Littlehorn will be frozen in a crippled walking position.  When talked to, there will be no voice for his prompts.  Additionally, the game seems to speed through the prompts, giving you no time whatsoever to read them, only pausing for your decisions.  If you shoot Daniel Littlehorn to knock him unconscious once more, the game freezes.  Resetting the console and entering the Offices again reset Daniel Littlehorn back to normal.
 * If you knock Daniel Littlehorn unconscious then when he comes back round pickpocket him he will have an ear in his inventory (killing him multiple times yields multiple ears) which can then be sold back to him. This means that it is possible to get infinite caps and bad karma without leaving the room.