Upon graduating with a law degree in 1983, Karnan enrolled as advocate before the Bar Council of Tamil Nadu and began to practice
civil law. During the time, he was selected as legal adviser to the
Chennai Metro Water Supply and Sewage Board, the government advocate in civil suits, and also as a standing counsel for the union government. In 2009, Justice
Asok Kumar Ganguly, then the Chief Justice of the
Madras High Court, recommended Karnan's name to the collegium for appointment as a judge. Despite his work not being well known to the collegium, his appointment was approved by the collegium headed by then Chief Justice of India
K. G. Balakrishnan. Speaking about it to
The Hindu, Ganguly justified the appointment because "he [Karnan] represented a certain community that should be represented in the choice of judges", but Ganguly, along with other members of the collegium, expressed regret over it later.
Controversies In November 2011, Karnan wrote to the
National Commission for Scheduled Castes (NCSC) alleging
caste-based harassment from other judges of the Madras High Court. Addressing a press conference organized in his chamber, he said that he had faced such "humiliation and embarrassment since April 2009" and that it still continued. He spoke of a specific incident when a judge "touched him with his foot". This led to an agitation in the campus of the Court. The then NCSC Chairman,
P. L. Punia, had forwarded Karnan's letter to the then Chief Justice of India, Justice
S. H. Kapadia. In late 2015, he wrote a letter to the Chief Justice
Sanjay Kishan Kaul saying he was going on a long leave because of the ‘dummy cases’ he was being allotted. In February 2016, the apex court transferred him to Calcutta High Court. On 23 January 2017, Justice Karnan published an open letter to the Prime Minister
Narendra Modi, naming "an initial list" of 20 sitting and retired Supreme Court and High Court judges allegedly involved in corruption. On 8 May 2017, Justice Karnan sentenced Chief Justice of India
Jagdish Singh Khehar and seven other Supreme Court judges to five-year rigorous imprisonment after holding them guilty under the
Scheduled Caste and Scheduled Tribe (Prevention of Atrocities) Act, 1989 and the amended Act of 2015. This led to the Supreme Court sentencing him to six months imprisonment for contempt of court on 9 May 2017. He finally retired on 12 June and after a week of his retirement, was arrested by the
Kolkata Police on 21 June 2017 from
Coimbatore. He was eventually released from prison on 20 December 2017 after completing his six-month sentence. ==See also==