He still feels nervous when he talks about the first time he investigated an honour killing. A woman from the martial Naicker caste had eloped with a Dalit man. The villagers tracked them down and brought them back. “They tied her up with a chain in a public place like a dog,” says Kathir, 50, founder of the Tamil Nadu-based non-profit, Evidence, which has legally pursued around 250 honour killings since 2005.