Nalini escaped the noose following a Tamil Nadu Cabinet decision and the Governor's assent to it in 2000. The clemency petitions of the other three were rejected by the President.
Timeline of the Rajiv Gandhi assassination case:
May 21, 1991: Former Prime Minister Rajiv Gandhi assassinated at an election rally by an LTTE suicide bomber in Sriperumbudur near Chennai.
May 20, 1992: Special Investigation Team (SIT) of the CBI files the chargesheet in the case before the TADA Designated Court at Poonamallee.
January 28, 1998: TADA Court awards death sentence to all 26 accused.
May 11, 1999: Supreme Court sentences Nalini, Santhan, Murugan and Perarivalan to death; commutes death sentence of three others to life; frees 19 others.
October 8, 1999: Dismissing their appeals, Supreme Court confirms the death sentence awarded to Nalini, Santhan, Murugan and Perarivalan.
October 17, 1999: The four death row convicts send clemency petitions to Tamil Nadu Governor.
October 27, 1999: Governor rejects the clemency petitions.
November 25, 1999: Madras High Court quashes Governor's rejection of clemency petitions; directs the Governor to pass a fresh order after obtaining the state Cabinet's views.
April 19, 2000: State Cabinet chaired by then Chief Minister M Karunanidhi decides to recommend commuting the death sentence of Nalini alone.
April 21, 2000: Governor accepts Cabinet decision to commute death sentence of Nalini.
April 28, 2000: State government forwards clemency pleas of Santhan, Murugan and Perarivalan to the President.
August 12, 2011: Union Home Ministry communicates to state Government about President's decision to reject clemency petitions.
August 26, 2011: Execution of three convicts fixed for September 9, 2011.
August 30, 2011: Tamil Nadu Assembly adopts resolution urging the President to commute the death sentence of the three.
August 30, 2011: Madras High Court stays execution of Santhan, Murugan and Perarivalan on their plea. Petitions transferred to Supreme Court later.
May 1, 2012: Supreme Court says it would hear the petitions of three convicts.
February 18, 2014: Supreme Court commutes the death sentence on grounds of delay in disposing their mercy pleas.
The court also says the state government may consider releasing the convicts under the powers vested with it.
February 19, 2014: State Cabinet decides to immediately release Santhan, Murugan, Perarivalan, Nalini, Robert Pious, Jayakumar and Ravichandran; sends its decision to Centre under Section 435 CrPC.