When Steve Rogers is first given the Super-Soldier formula, Kruger managed to infiltrate the lab as a government official named "Fred Clemson". However, he revealed his true allegiance when his bullet cut down Dr. Abraham Erskine, the creator of the formula. As Kruger attempted to escape, he turned on Erskine's electric Omniverter and was killed via electrocution. Because of his interference, Erskine was dead and the knowledge of the Super Soldier Serum was lost, leaving Steven Rogers as the only Super Soldier.
Marvel Cinematic Universe
Kruger appears as a minor, yet pivotal antagonist in the 2011 MCU film Captain America: The First Avenger, where he was portrayed by Richard Armitage. Like his comic book counterpart, Kruger is disguised as a government official named Fred Clemson and witnesses Steve Rogers' transformation into Captain America. Once the process is complete, Kruger detonates a bomb, and in the chaos, kills Abraham Erskine. However, unlike his comic book counterpart, Kruger is not killed in the lab, but manages to escape along with a sample of the doctor's serum.
Despite Agent Peggy Carter managing to kill Kruger's getaway driver, he seemingly escapes, but Rogers escapes from the lab and pursues Kruger's car through the streets of Brooklyn, eventually latching onto the roof of Kruger's car. Failing to shake Rogers off, Kruger escapes from the car and takes a nearby child hostage, threatening to kill him if Rogers doesn't back off. When Rogers continues his pursuit, Kruger attempts to kill the boy, but his gun is out of bullets, so he instead throws the boy into the harbor as a distraction. The boy is, fortunately, unharmed and able to swim, and urges Rogers to "go get him."
With his mission mostly complete, Kruger boards an advanced HYDRA submarine and prepares to return to Germany; however, before he can, Rogers dives into the water and catches up with him. Shattering the sub's cockpit, he grabs Kruger, pulls him onto the dock, and subdues him, causing the serum to be destroyed. However, as Rogers prepares to interrogate him, he bites down on a concealed cyanide pill. In his dying breaths, Kruger proclaims that he is "the first of many" and that if he were to "cut off one head, two more would take its place." He then declares, "Hail HYDRA!" before finally dying.
Kruger was an extremely cunning, ruthless and intelligent individual, being knowledgeable to deal with situations of danger or combat easily. He was ruthless enough to hold a child hostage and then kill him once he was no longer useful. In addition to his intelligence and ruthlessness, Kruger was also an extremely loyal individual to HYDRA Organization, being obsessed with only one goal; to steal a sample of the Super Soldier serum so that HYDRA can create its own army of Super Soldiers and kill Erskine so that none of HYDRA's enemies could do the same. He also knew when to "retire" by killing himself with a cyanide pill hidden in his mouth to avoid interrogation and capture.
The film The First Avenger came out in July 22, 2011, a year before The Hobbit: An Unexpected Journey, where Kruger's actor Richard Armitage had portrayed Thorin.
Heinz Kruger has the same role as Joe Chill from the Batman comics and The Burglar from Spiderman comics, although regardless if he had came and killed Erskine, Rogers would have already completed his transformation into Captain America, whereas Spider-Man and Batman had to have these tragedies befall them in order for them to turn over to crime fighting.