Fallout 3/You Gotta Shoot 'Em in the Head...

You Gotta Shoot 'Em in the Head is a quest given by a Crowley in the Underworld. He contracts you to kill four people: Allistair Tenpenny, Dave, Dukov and Ted Strayer. The reason was that these people are bigots.

Crowley will want proof that three of the four people are dead, such as with a key. However, killing three of the four individuals will result in negative karma as there is a non-violent way of dealing with them, through various speech or skill checks (or in some cases, caps.) However, Crowley will pay the most caps for headshots.

The three keys, along with one other in Fort Constantine, are required to obtain a powerful item.

Dave
Dave is located in the Republic of Dave to the north-east. Beyond direct force, there are two ways to obtain the key:
 * Rig the election within the Republic of Dave so that either Bob of Rosie wins the election. You need to convince either one of them to run for the election, and when Dave starts counting the ballots, quickly remove the ballots from the box.
 * Use the speech skill to obtain it from him.

Dukov
Dukov is located within the DC area, and is in control of what amounts to a personal brothel.
 * He will sell the key.

Ted Strayer
Ted is located within Rivet City, and is the son of a mercenary that was sent to Fort Constantine.
 * He can sell the key, but can also be intimidated into giving it away.

Allistar Tenpenny
Tenpenny gives a reward for killing Crowley if you warn him about the contract, which is paid in advance.

Reward
When you return to Crowley, you can collect 25 caps per kill or 100 caps if you did a clean headshot. However, you can get additional caps from him if you tell him that some of the people weren't bigots, and you also have the option of lying about headshots as well.

You have the option of keeping the power armor to yourself. Head to Fort Constantine far to the northwest and enter the building. Look for a corpse on the ground for the final key to the room containing the power armor.