Poonam, a 24-year-old housewife residing in Chhawla area in South-West Delhi, was arrested along with her paramour Sushil Kumar and his relative Deepak for allegedly murdering her mother-in-law.
The woman, in her sixties, was attacked by three persons with hockey sticks and knife at her home in the presence of her husband on the intervening night of August 12 and 13, police said today. The trio managed to rob gold jewellery and money.
Jagdish Chandra, the woman's husband, tried saving his wife but in vain.
She was declared brought dead when taken to a near-by hospital.
During investigations, police suspected the role of an insider in the crime and zeroed-in on Poonam, the daughter-in-law of the deceased.
"She revealed that her marriage was solemnised four years ago against her will and that she had a boy friend (Sushil) since her school days. She was in constant touch with her paramour who used to come to her house when family members are away," Ravi Shanker, Additional Deputy Commissioner of Police, South-West District, said.
Poonam's mother-in-law noticed Sushil's presence and warned her daughter-in-law against such a relationship and even threatened that she would tell her son.
"Poonam told all this to her paramour and hatched a well planned conspiracy in order to eliminate her mother-inlaw with the help of Deepak, Sushil's relative," he said.