Police said Natarajan(35), used to target elderly women living alone to murder them and rob their jewels.
Police who investigated the suspicious death of Subbulakshmi(65), wife of a retired headmaster at Konampatti last week, found that she had been strangulated to death.
Police had exhumed the body on a complaint from her daughter, who is a doctor, and found during post-mortem yesterday that she had been strangulated to death for gain.
Investigations with the neighbours later revealed that Natarajan had visited the house and he was detained for interrogation, police said.
He was then arrested, police said.