On July 7, Krishna Devi was found dead in the house where she lived with her nephew Chunni Lal, they said.
Upon questioning a number of people, police zeroed in on the accused, Dhiraj (21), who used to work as a caretaker of Krishna Devi's husband around one-and-half-years ago and had recently visited the woman, said DCP (West) Pushpendra Kumar.
During interrogation, Dhiraj admitted to killing the woman alongwith his three accomplices Hansraj, Aman and Sumit and looted around Rs 12 lakh from the house, he claimed.