LUCKNOW, March 23 -- The 55-year-old Roop Narayan Chaurasia, who was admitted to a hospital in critical condition in a suspected mass poisoning case involving a family in the Banthra area, died on Sunday, police said. The incident took place in Neewa village on Friday, where a 52-year-old woman and her son, who allegedly consumed poison, were declared dead at a private hospital, while the family's head, 55-year-old Roop Narayan Chaurasia, was admitted to hospital in critical condition. Assistant commissioner of police (ACP) of Krishna Nagar, Rajneesh Verma, confirmed that Roop Narayan Chaurasia also died at around 7 pm on Sunday, with the hospital notifying the police of his death. He added that a handwritten note recovered from the son's pocket claimed that the three consumed poison by choice and that no one else should be held responsible. However, Verma said the note is now under scrutiny, as several aspects of the case do not align with a straightforward suicide narrative. Roop Narayan's younger son, in his 20s, was also present during the incident and is currently under interrogation. So far, no direct evidence of his involvement has been found, although questioning is ongoing, the ACP added. Police are recording statements and piecing together the sequence of events leading up to the suspected poisoning. Some officials familiar with the case said the biggest challenge for investigators is the absence of any physical evidence related to the poison. Despite a thorough search of the house and surrounding areas, police have not found any container, wrapper, or bottle that could indicate the source of the substance. "This is unusual. In most such cases, some trace of the poison container is recovered," Verma said, adding that the possibility of the substance being brought from outside and the evidence removed later is being examined. Forensic teams have seized cooked food from the house and sent it for laboratory analysis to check whether the poison was mixed in it....