NEW DELHI — India's Supreme Court on Tuesday commuted the death sentences to life in prison for three men convicted of playing minor roles in the assassination of former Prime Minister Rajiv Gandhi. The three have served more than 20 years on death row in Vellore Prison, in southern Tamil Nadu state. They denied knowing anything about the plot to kill Gandhi as he was campaigning in May 1991 for a return to the prime ministerial office. He was killed along with 17 others, including the female suicide assassin, as she greeted him with a garland of sandalwood beads and a bomb strapped to her chest during a rally in India's Tamil Nadu state. The attack — orchestrated by Tamil Tiger rebels in neighboring Sri Lanka — horrified the nation and virtually ended Indian support for the rebels' in their decades-long fight for an ethnic Tamil homeland. All of the assassination's masterminds were killed during or after the attack. The three men on death row, however, were among 26 convicted of playing minor roles in the plot. While they have been reviled across much of India, many ethnic Tamils in the south believe they were duped into taking part in a plot they knew little about. Indian national Arivu Perarivalan was found guilty of buying a 9-volt battery used in the bomb, while Sri Lankans Murugan and Santhan — who use only one name — acknowledged they were Tamil Tigers rebels but only pawns in a larger game they barely understood. Their lawyers argued that executing the three now, after they had already served long prison terms, would amount to an unconstitutional double punishment. “This is a landmark judgment,” said the men's lawyer, Yug Chaudhry, applauding the court for rejecting the idea that the prisoners should show proof of “the scars of mental suffering” in awaiting their executions for decades. Human rights activists and lawyers cheered the court's decision. A “delay in disposing of mercy petitions of death row convicts amounts to degrading, inhumane treatment. It amounts to torture,” rights lawyer Vrinda Grover said. “In this case also there has been substantial delay.” The Vellore Three, as they are now known, were the only convicts left on death row in the case, after 23 others were released or had their sentences commuted to life. The last clemency granted was for Murugan's wife and the mother of his child, Nalini Sriharan, after Gandhi's widow, Sonia, met with her and asked in 1999 that no one be hanged. Sonia Gandhi is now leader of the governing Congress Party and her son Rahul is seen as the party's prime ministerial candidate in parliamentary elections that must be held by May. — AP