Agent Peterson is a hand-to-hand combat specialist S.H.I.E.L.D. agent, possessing at least six black belts. He was tasked with helping Nick Fury to evaluate the results of Thaddeus Ross' "Super-Soldier Program" on Bruce Banner.
Nick Fury, investigating a series of rumors concerning Bruce Banner, General Thaddeus Ross and their attempt to recreate Abraham Erskine's Super Soldier Serum, approached Banner, trying to earn his trust but prompting him to leave in a hurry.
Under Fury's orders, Agent Johnson started flirting with Banner, while Agent Peterson acted as Johnson's jealous boyfriend, threatening Banner. Fury acted as he was trying to intervene, but Peterson punched him in the face to make Banner feel more menaced.
Despite Banner's warnings, he transformed into Hulk, knocked Peterson out and started to wreck the whole bar. Fury, startled by this transformation, remained calm and tried to reason with Hulk, as the man inside wouldn't want to hurt innocent people. Fury's demeanor made Hulk leave the bar without hurting anyone else.