De Kock started to make a name for himself during the Rhodesian war, in which he was described as a "warrior". However De Kock "never received psychological treatment for the war trauma he suffered in Namibia". In 1983 De Kock was transferred to the police death squad where they "hunted down and killed anti apartheid activists". During the next few years the farm at Vlakplass was used for their regime, where they "were soldiers, used to fight a secret war."

At the peak of De Kock's career he had been decorated for bravery, outstanding service and combating terrorism. This however did not last long and by 1992 De Kock was involved in common crime himself. And in 1994 after the elections De Kock was arrested, "he was charged with 121 crimes" and "more than 80 state witnesses testified against him, many former Vlakplass policemen." De Kock was "apartheid's most evil face."