P Ravichandran, the 16th accused in the killing of former prime minister Rajiv Gandhi, filed a petition with the Supreme Court on Monday asking for interim bail following AG Perarivalan's release. After 30 years in prison, Ravichandran requested bail last month from the Madras High Court until his formal discharge was completed, but his request was denied. The High Court had noted that it lacked the Supreme Court's unique authority. When Ravichandran, then 19 years old, was detained in 1991 in connection with the assassination of Gandhi, he also asked Chief Minister MK Stalin for assistance in securing the release of six other prisoners.