Hitman

Hitmen are hired killers hunting the Lone Wanderer in 2277.

Burke's hitmen
These killers appear only if you have disarmed the bomb in Megaton. They look like Talon Company mercs. They greet the player with a threat, cannot be bargained with, and then open fire. They carry a contract for extermination signed by Mister Burke, even if he is dead.

Slaver-hunting hitmen
These killers appear once you have completed the Strictly Business quest or have enslaved a certain number of people (number required unknown). These hitmen look like wastelanders, greet the player as "Slaver scum," and then attack. These hitmen carry the Contract Killing note demanding "Wasteland justice."

Appearances
Hitmen appear in Fallout 3.