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 Independent 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 Brittle’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.”
Today’s report was the latest from the watchdog into failings in the way police forces deal with domestic violence cases.
The IPCC is currently investigating contact between Nottinghamshire Police and a 31-year-old woman prior to her death in Newark in March.
Denise Skilbeck was found dead at a house in the Wharf area of the town. She had died of head injuries.
Gary Spalding, 34, was jailed for life, with a minimum term of 20 years, by a judge at Nottingham Crown Court after admitting her murder.
Nottinghamshire Police referred the death to the IPCC on March 17, 2011 because of prior police contact with the woman. The police contact dates between May 2008 and March 13, 2011 and relates to a number of domestic incidents, the watchdog said.
In another case last year, Nottinghamshire and South Yorkshire police officers were found to have failed to take “crucial steps” in the lead up to a frenzied knife attack by a man on his wife in front of their young son.
The IPCC examined contact both forces had with Gail Hdili before she was attacked by Adel Hdili in Nottingham in January 2009. She was left with permanent scars and lost her sight in one eye.
The incident happened after Mrs Hdili had reported domestic abuse to the police, the watchdog found.
It pointed to risk assessments which were not completed, calls which were not handled properly and specially trained officers who were not used.
Tunisian Adel Hdili admitted wounding in July 2009 and was sentenced to a nine-year prison term, to be followed by deportation.
The watchdog is also examining how Leicestershire Police officers handled complaints of harasment linked to a woman who was later killed with her two children by her former partner.
Aram Abdul Razaq Aziz, 32, is believed to have murdered Joy Small, 24, and their children Aubarr, three, and Chanarra, two, before taking his own life in Leicester in February.
The IPPC said Leicestershire Police identified eight occasions between 2006 and 2010 where they had contact with the family related to reports of harassment and allegations of domestic abuse.
The same force was criticised earlier this year by the IPCC for adopting a “haphazard approach” to dealing with a woman who was eventually stabbed by her ex-partner outside a primary school after enduring a campaign of harassment.
The watchdog said Leicestershire Police had failed to recognise warning signs leading up to the attack on the 32-year-old in April.
The woman reported several incidents of harassment by Simon Lockton leading up to the violent attack, but the IPCC said the force adopted a “haphazard approach” to dealing with her.
The woman survived the attack outside Greenfield Primary School in Countesthorpe, Leicestershire, and last November Lockton was given an indeterminate sentence for public protection at Leicester Crown Court.
But the IPCC said police failed to realise the risk Lockton posed - despite previously seeing a similar pattern of behaviour with him relating to a different woman.
It found officers failed to carry out proper risk assessments and complete required paperwork, while others failed to recognise the nature of the incident they were dealing with.
Leicestershire Police have also called for magistrates to be offered extra training in domestic abuse awareness.
The proposal was made last year by officers from the force following a review into the death of mother-of-two Karen Brookes.
Ms Brookes was murdered by Kevin Sainsbury in November 2009 after she endured months of physical and verbal abuse from her former lover.
At the time of the brutal attack, 51-year-old Sainsbury, who had been in a relationship with Ms Brookes for around 15 years, had been granted bail by magistrates after he was arrested and charged with threatening to kill her.
He was sentenced at Nottingham Crown Court to a minimum of 25 years in prison for the murder of the 37-year-old.
After the trial, unnamed magistrates at Hinckley were criticised by Ms Brookes’s family for freeing Sainsbury by granting him bail.
The family said at the time: “We feel that Karen was let down by the justice system prior to her death.
“He had a violent past, some of which was more recent, and these facts must have been known to the magistrates that dealt with him.
“He certainly should not have been released to then be able to go on and commit this horrific crime that took the life of Karen and destroyed so many other lives in the process.”
Leicestershire Police refused a freedom of information request to release an unedited copy of the report into Ms Brookes’s death, but did confirm it included a proposal for domestic abuse awareness training.
A statement released by the force at the time said: “Despite presenting the magistrates with what the Independent Police Complaints Commission (IPCC) called a ‘robust bail application’, Kevin Sainsbury was not remanded into custody.
“An internal review recommended that consideration could be given to providing specialist domestic violence awareness training to magistrates and CPS prosecutors to provide them with a greater understanding of patterns of offending in domestic abuse cases.
“This could be led by specialist police domestic abuse officers and include input from domestic violence refuge charities and organisations, and possibly victims.”
Nottinghamshire Police has said it unreservedly accepts the recommendations of the IPCC report.
In a statement released by the force, Paul Broadbent, assistant chief constable of Nottinghamshire Police, said he deeply regretted Ms Brittle’s death and the circumstances surrounding it and that he had apologised to the woman’s family.
He said the force had revised its approach towards responding to, and identifying, incidents of domestic violence and abuse since the incident.
This involved an overhaul of working practices, specifically in relation to the identification and management of the risks faced by victims, he said.
A new training programme has also been put in place for all police officers and staff who deal with such cases.
The force has put together a 20-minute film with the help of Ms Brittle’s mother, which will be shown as part of the programme.
Six officers have appeared before a misconduct meeting and admitted their individual failings in relation to the case.
One received a written warning while three others received management advice, Mr Broadbent said. No action was taken against the remaining two.
Four others, who were not required to attend the meeting, have been subject to unsatisfactory performance procedures, he added.
Mr Broadbent said: “We will never know, as the IPCC report sets out, whether we could have saved Casey’s life had we taken a different approach to those 11 incidents involving Casey and her violent partner.
“What is certain, however, is that we could and should have done more. That is a cause of deep and lasting regret and I have formally apologised to Casey’s mother.”