G Manikandan was attached to the Armed Reserve Police wing.
A 26-year-old police constable in Chennai was found dead with bullet injury this morning.
Police suspect G Manikandan, who was attached to the Armed Reserve Police wing, could have shot himself dead. "We are investigating. It appears to be a case of suicide," a senior police officer told NDTV.
Mr Manikandan is from Tiruvarur district. Today, sources say, is his birthday.
Investigation is underway.