In May 1978, De Kock was transferred to South West Africa and joined the security branch in Oshikati. In 1979, he co-founded Koevoet, an SAP counter insurgency unit tasked with combating the People's Liberation Army of Namibia (PLAN) during the South African Border War. Koevoet was regarded as a highly effective unit, but its reputation was marred by allegations of brutality towards civilians. Its successes in tracking and killing PLAN guerrillas prompted the SAP to consider setting up a similar division in South Africa. In 1983, the SAP transferred De Kock to C10, a counter-insurgency unit headquartered at a farm called Vlakplaas, located west of Pretoria. De Kock, who had established a reputation for commitment during his tours in Rhodesia and Namibia, was promoted as the unit's commanding officer two years later. Under his leadership, C10—later known as C1—became a death squad which hunted down and killed opponents of the National Party and the apartheid system. De Kock first became prominent during his testimony in the Truth and Reconciliation Commission, during which he made multiple revelations relating to ANC deaths. De Kock has been interviewed a number of times by Pumla Gobodo-Madikizela, who ended up releasing a book, "A Human Being Died That Night", about her interviews with De Kock, her time on the TRC, and what causes a moral person to become a killer. Upon being convicted on 30 October 1996, De Kock was sentenced to two life sentences plus 212 years in prison for crimes against humanity. The eighty-nine charges included six counts of murder, as well as conspiracy to murder, attempted murder, assault, kidnapping, illegal possession of a firearm, and fraud. De Kock served his sentence in the C Max section of the Pretoria Central Prison. In a local radio interview in July 2007, De Kock claimed that former president FW de Klerk's hands were "soaked in blood" and that de Klerk had ordered political killings and other crimes during the anti-apartheid conflict. These claims were in response to de Klerk's then-recent statements that he had a "clear conscience" regarding his time in office. "The Sunday Independent" reported in January 2010 that De Kock was seeking a presidential pardon from President Jacob Zuma in exchange for more information about the apartheid government's death squads, and that a three-hour meeting between Zuma and the incarcerated De Kock took place in April 2009.