Originally incarcerated in Denpasar's prison, he was moved to the high-security prison island of Nusakambangan in October 2005. Together with the two other bombers who received death sentences, he launched a constitutional challenge against the use of firing squads. Mukhlas preferred beheading. Despite an initial decision by Muklas, Amrozi and Imam Samudr to not seek a Presidential pardon, on 21 August 2006, Muklas and his co-conspirators authorised their lawyers to file a last appeal which was lodged on 7 December on the basis of retroactive legislation. On 25 September 2008, the Supreme Court of Indonesia rejected the final appeals of Imam Samudra and Mukhlas; having dismissed Amrozi's appeal earlier that month. In October 2008 he remained unrepentant and claimed revenge would be taken for his death. During the month, his final appeals were rejected by Indonesia's constitutional court and the Attorney General's office announced that he would be executed by firing squad in early November 2008.