Police are facing questions over their contact with a mother and her two-year-old daughter who were found shot dead in their home.
Detectives said that for two years they had been aware of a number of incidents involving the victims Christine Chambers, 38, and Shania, two, and a man in custody, named locally as her partner David Oakes, 50.
Officers were called to Ms Chambers' home in, Braintree, Essex at 3am on Monday where they found the bodies. Ms Chambers' 10-year-old daughter had escaped the house and alerted family members who called police.
A 50-year-old man is under guard in hospital where he is undergoing treatment for shotgun injuries which are not thought to be life-threatening. He has yet to be arrested, but police are not searching for anyone else in connection with the deaths.
It has been reported that Ms Chambers, known by friends as Chrissie, was in a dispute with Mr Oakes. A David Oakes and a Christine Chambers were listed to attend Chelmsford County Court for a family proceedings hearing, an official at the court confirmed.
Neighbours in Bartram Avenue claimed police could have prevented the tragedy as Essex Police said it had referred itself to the police watchdog promising a "full and fundamental review of the circumstances surrounding this contact in order to ensure there is total transparency".
At a press conference at Braintree Town Hall Assistant Chief Constable Gary Beautridge, head of the Kent and Essex serious crime directorate, said: "There have been a number of incidents where contact between the man in custody and Chrissie Chambers have been referred to Essex Police over the course of the last two years."
He added: "It is too early to tell if there will be lessons to learn from this case but we will be examining every aspect of it. If there are any mistakes or shortcomings we will not shirk our responsibilities. That is why we have voluntarily referred this matter to the Independent Police Complaints Commission."
There had been angry scenes outside the house and a man shouted at police: "You knew this was going to happen, you could have stopped it". He was led away by officers.
One neighbour, who declined to be named, said that Ms Chambers had been living in fear. She added: "We all knew she had problems and were worried about what might happen to her."