A Kerala court on Friday found 13 RSS activists guilty in the April 2008 murder of a local CPI(M) worker.
Additional sessions court judge TK Unnimol will pronounce the quantum of sentence on Saturday.
According to the prosecution, the accused -- 16 men armed with swords, iron rods and other weapons -- attacked Vishnu at Kaithamukku and killed him.
While one accused died in 2008, another was acquitted by the court on Friday and one is at large.
Charges against the accused include that of murder, conspiracy and unlawful assembly.