A domestic help poisoned four members of a family in Noida and fled with cash and jewellery, police said.
One lady died and three other members of the family were battling for their life in hospital.
The servant identified as Akash is missing, Noida SSP R K Chaturvedi said. The main door of the house in sector 50 was found locked from outside.
Chaturvedi said the cupboards were open and some valuables reportedly missing.
The residents were identified as Ajay, his wife Sandhya and their children Rakshak and Tara. Sandhya was declared brought dead by Prayag Hospital while the condition of three other family members was stated as stable.
Doctors said they were unable to identify the chemical used by the servant to drug victims.
The incident came to light when landlord Ajai Maini found the couple and their children lying unconscious. They were immidiately rushed to hospital.