A four-year-old girl was shot dead by her father during a violent row between her parents, police said.
The girl's mother, aged 40, is fighting for her life in hospital after being shot in the head.
Police believe the 56-year-old man, named locally as Andy, then shot himself at a house in Church Hill, Aldershot, Hampshire.
Officers were called to the terraced property when a neighbour dialled 999 to report a row shortly after 10am on Tuesday.
Speaking outside the house, Detective Inspector Darren Rawlings said they were met with a "very traumatic" scene.
He said officers attempted to resuscitate the girl but she was pronounced dead a short while later.
The woman was taken by air ambulance to a central London hospital where her condition is described as "serious and critical".
Mr Rawlings said the shooting took place as the woman dropped the girl off at her former family home.
He said the couple split up around four weeks ago and investigators are not looking for anyone else.
Mr Rawlings said: "This is a tragic death of a four-year-old child. What police are working towards is to establish the identity of those involved."