The couple was murdered over property worth several crore, the official said.
The murder of a couple here, who were found dead with their throats slit, was plotted by their adopted daughter and her lover to grab their property, police said on Wednesday.
The bodies of Munna Lal Uttam (62) and his wife Raj Devi (55) were found in separate rooms on the ground floor of their residence in Barra-II on Tuesday.
Akanksha alias Komal was arrested on Tuesday while her lover Rohit Uttam is absconding, they said.
Akanksha was adopted by the couple over 20 years ago, a senior police official said.
The couple was murdered over property worth several crore, the official said, adding that the victims wanted to give a part of their land to their daughter-in-law.
Police got suspicious of the woman when they spotted an injury on her finger. She was questioned but tried to mislead police. She eventually broke down and confessed to have murdered the duo with the help of her lover.
Police have launched a search for Uttam, an official said.
The deceased couple used to live with their son Anoop and Akanksha.