The police said that the accused is an alcoholic and is being interrogated.
An 85-year-old woman died after she was allegedly raped in her house in Hafizganj on Monday, police said.
The police have arrested the 35-year-old accused, identified as Rakesh, who lives in the neighbourhood.
Senior Superintendent of Police Anurag Arya said the victim resided alone after her husband and son had died. The woman's brother and sister-in-law live in the neighbourhood and her daughter-in-law lives with them.
According to the daughter-in-law, when she went to the victim's house at around 1 pm, she was stunned to see Rakesh raping her mother-in-law, Arya said.
The police said that when the daughter-in-law raised an alarm, the accused escaped and the family immediately informed the police. Meanwhile, the old woman died after the attack.
The police reached the site and succeeded in arresting the accused.
Mr Arya said that the accused is an alcoholic and is being interrogated.
A panel has been asked to conduct the post-mortem of the woman.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)