Marty has only been at the Reservation for about ten years. He stumbled upon the facility when he was searching the wasteland for ingredients to make a new mind-altering drug. When the ghouls of the Reservation told him of the "communal" lifestyle of the Reservation, he thought it was groovy and wanted to stay. When he got the job offer to work at the chemical lab, it was like a gift from heaven, and the original lab techs were very impressed with Marty's skills. 
This drug has the same effect on ghouls as it does on humans – it mellows the individual to the point beyond apathy and couples that with feelings of ecstasy. In order to take smooch, the individual must wrap the greasy looking green goo in a thin paper and smoke it. Another way, though not as quick an effect, is to bake smooch into a bread source. One could eat smooch directly, but the taste is so vile that most would puke it back up, even a ghoul.
Smooch dealer - Aside from an interesting drug source, the Prisoner can capitalize on and distribute it to outside sources, like Dusty or Yuri. Marty is also not so keen on Willem Clark's plans. Perhaps a byproduct of smoking too much smooch, Marty would like to have more interaction with friendly humans, and he is convinced if he had the opportunity to spread smooch around the human settlements, the humans would become more accepting of ghouls.
After the player earns Klik's trust, she will offer to teach the player their unarmed melee and unarmed fighting style.
During the day, he is usually putting together stimpaks and Rad-X kits for trade on the surface. During late hours of the night, he sneaks into the chemical lab and concocts a soothing, mellowing drug he calls "smooch".
Marty has not appeared nor is he mentioned in any published game. He was to appear only in Van Buren, the canceled Fallout 3 by Black Isle Studios. It is not certain if he will appear in any future Fallout game.