The gun that Moira Brown hired to guard her properties is notorious for his supposed restless nature, as he is never witnessed sleeping during store hours. He is a rather bit self-centered, judging by his gravely voice and the fact that he never seems to like anyone. Regardless, this merc never questions his job of protecting the inventory of the Craterside Supply, as his very presence is enough to thwart shoplifters.
He stays out of the way of Moira's scientific pursuits, taking care that he has no business intervening in his employer's crazy experiments, as that is not what his contract calls for.
He doesn't seem to like anyone and talks in a gravely voice.
Due to his position and high chance of detecting you, it is very difficult to successfully pickpocket him.
He seems to regenerate his supply of 5.56mm ammunition every day or so.
If the player character asks Confessor Cromwell about local gossip, he will tell you that Moira has hired a mercenary who "never sleeps". He does in fact sleep, however, just quite briefly and not until 5 AM.
Killing the mercenary may sometimes cause all of the citizens in Megaton to become hostile towards you. They will remain hostile even if you go away and wait for several days before entering Megaton again.