According to the District Police Office, Banke, Sanjay Kumar Barma, 30, of Duduwa rural municipality of Banke district shot wife Sunita Barma, 28, on Thursday night.
Sunita, who sustained bullet injuries at her right hand and side of the abdomen, died on the spot, said the police.
Sanjay, who is mentally ill and has been taking medicine, confessed the crime, said the police. Sanjay said he shot his wife on suspicion of her illegal relation with a house helper.
Police have started further investigations into the case.