A young mother was beaten to death by her violent ex-partner after police failed to intervene 11 times, investigators said today.
Casey Brittle, 21, repeatedly called Nottinghamshire Police before she was murdered by Sanchez Williams in front of her two-year-old daughter.
Amerdeep Somal, a commissioner at the Independendent Police Complaints Commission (IPCC), said Sanchez, from Nottingham, was "well-known to local police for his propensity for violence and threatening behaviour".
"In this case it is clear that a number of officers failed to perform to the level expected of them and basic actions, that may have helped others see the full picture of her suffering, were not completed," the commissioner said.
"No consideration was given to why Casey was reporting domestic abuse but then subsequently saying that she did not want police help."
Ms Brittle died from a series of injuries to her head, including a fractured jaw, cuts and bruising in October last year.
Williams, of Lathkill Close, Nottingham, was jailed for life after he admitted murdering Casey at her home.
Police received allegations of domestic violence and abuse against Ms Brittle between September 2008 and August 2010.
The police watchdog recorded a number of force and individual errors.
An IPCC spokesman said: "As a consequence of the investigation, six officers faced misconduct for their roles in three incidents, while a further four officers have been dealt with through unsatisfactory performance procedures.
"Aside from failures by individual officers, the investigation identified the lack of a thorough corporate approach to domestic abuse from Nottinghamshire Police.
"This resulted in a lack of knowledge and support for officers in their attempts to provide victims with the necessary support."
Ms Brittle's mother Victoria Blower refused to blame police as the report was published.
"I know mistakes were made in dealing with previous attacks involving Casey, but there is only one person responsible for my daughter's death and that is Sanchez Williams," she said.
"Maybe one small change in the way things were handled could have saved her, or maybe Sanchez Williams was a time bomb just waiting to explode and nothing that anybody could have said or done was ever going to prevent him from murdering Casey."
Ms Brittle's daughter was heard crying and screaming as her mother was beaten to death.
The little girl walked into the room four times to find her father carrying out the attack.
A next-door neighbour was said to have heard Ms Casey's daughter screaming "I want my mummy" as her father carried out the killing.
As her mother lay unconscious after the attack, the little girl stayed in the bedroom on her own for two hours.
Ms Blower said she hoped lessons would be learned after the "worst day" of her life.
In her statement, she said: "Nottinghamshire police have taken positive action since Casey's death and I am glad to have been involved in their work to improve the handling of incidents of domestic violence.
"Although there is no way of knowing whether Casey could have been saved, I sincerely hope that in the future a better attitude towards women at risk will ensure their safety.
"I would also urge people not to close their own eyes and ears if they see or hear somebody experiencing domestic abuse, but to pick up the phone and call the police.
"You never know, it might be your call that saves a person's life. It is too late for my beautiful bubbly girl, but don't let it be your daughter, neighbour or friend who is next."