Lars is most likely to be the second person encountered upon finding Junktown, as he stands just inside the gate. He is a heavily muscled man with a mustache, bearing many scars from both knives and guns.
Lars is an intolerable man, hardened through many years of adversity. He does not seem to have any problem with working for Killian Darkwater, as both strive to keep control and order in the town.
Bust the Skulz gang: Suspicious of the illegal activities going on around town, Lars needs help procuring evidence. He asks the Vault Dweller for any evidence against the local gang, the Skulz, initiating the quest to bust the Skulz.