The special CBI court judge Dhirendra Kumar Pandey convicted Dhruv Kumar Jaiswal, Sheikh Munna Khan and Iliyas Bari under sections 302, 307, 120B/34 of IPC and section 27 of the Arms Act.
Chandrashekhar was shot dead and several others were injured by the trio at a CPI(M-L) Liberation rally in Siwan district on March 31, 1997.
CPI(M-L) Liberation leader Rameshchandra Kushwaha lodged an FIR against the three persons charging them with the murder of Chandrashekhar.
The state government had subsequently recommended and handed over the probe to the CBI.