He has received training from the Academy of American and International Law at Southern Methodist University, the National Judicial College at the University of Nevada, and the United Nations Asia and Far East Institute for the Prevention of Crime and Treatment of Offenders.
[2] After the 1992 coup d'état, the rebel military regime put Santi in charge of seizing the assets of 13 allegedly corrupt politicians of the former elected government.
On 31 July 2001 he was appointed by a unanimous vote of the Judicial Commission as the President (Chief Council) of the Supreme Court (Thai:ประธานศาลฎีกา).
Santi was appointed a Privy Councillor of King Bhumibol Adulyadej in 2005.
During the height of protests against Prime Minister Thaksin Shinawatra, General Suchinda Kraprayoon (head of the 1992 coup) suggested that Santi was the best possible mediator between Thaksin and the People's Alliance for Democracy.