The motive behind the killings is believed to be a dispute over property, the police said.
An elderly couple was allegedly murdered by their daughter-in-law and two of her associates in Delhi on Sunday, the police said.
The two senior citizens, both in their 70s, lived in Delhi's Gokulpuri area with their son, daughter-in-law, and their grandchild. According to the police, their daughter-in-law Monica sought the help of two men - one of whom is believed to be her boyfriend - to carry out the murder.
The elderly man Radheshyam Verma, a retired government school vice principal, lived with his wife on the ground floor while Monica, her husband, and their son occupied the first floor. At 7 pm on Sunday, Monica allegedly led her boyfriend and another man to the terrace of the house where they hid for a few hours at night before entering the elderly couple's bedroom and slitting their throats.
The couple's son Ravi had last seen his parents at 10.30 pm on Sunday, the police said.
The bodies were sent for post-mortem and further investigation into the matter is underway. While Monica has been arrested, a hunt is on to track down her boyfriend and the other associate.
The motive behind the killings is believed to be a dispute over property, the police said, adding that at least Rs 4 lakh cash, which was part of an advance payment for the sale of the house, is also missing from the couple's home.