About 10am on the morning of the killing an HBC worker faxed and phoned police about Ms Morris' escape and threats, but was unable to get through to the local station.
She eventually called 111 just after 11am and spoke to the Police Northern Communications Centre.
At 11.13am two police officers were sent to Ms Morris's address. They were unable to find her, but spoke briefly with Ms White as she mowed her lawn, and advised her to call police immediately if she saw Ms Morris. The officers then left.
Shortly afterwards police received a second call from the HBC advising that another neighbour, who was not named, had reported that Ms Morris was with her and was making threats to harm Ms White.
A communications dispatcher mistook the information from this call as a repeat of the information from the first call, and subsequently no officers were dispatched to the neighbour's address to apprehend Ms Morris.
At 12.19pm the neighbour called police to say Ms Morris had just left her address.
After a few minutes she called again to say Ms Morris had returned with blood on her face.
Officers arrived to discover that Ms White had been attacked and killed in her home with a blood-stained hammer found nearby.
They quickly found Ms Morris and took her into custody.
The IPCA found the police had the information and the ability to prevent the death of Mrs White if they had responded appropriately to the available information.
"The key failure was that officers were not sent to (the neighbour's) address after the second call from the Henry Bennett Centre alerting Police to the location of Ms Morris.
"If that had occurred, it is likely that Mrs White's death would have been prevented."
The failure of the attending officers to conduct more extensive enquiries at the time of the first house visit; and the communicator's poor handling of the second call to police were "unreasonable and unjustified", the report said.
There was also inadequate handling of, and response to, the first call to police and the later failure to clearly register as a priority that the location of Ms Morris was known and to dispatch officers at that point, the report said.
Police have said they have taken remedial action in connection with several staff involved.
Police have also taken action since this incident to improve relevant policy and training, as well as clarifying with the Ministry of Health each agency's responsibilities when a mental health patient is reported missing, the authority said.
The authority supported the recommendations made in a police review of their response to people with mental impairment and supports further training to all staff on relevant policy and legal powers.
The Authority also supported the continued roll-out of the Crime Reporting Line to all police districts and recommended that this line be used for the notification of missing mental health patients.
HOW THE POLICE FAILED:
* The initial response to the notification of Ms Morris' escape.
* The lack of thorough questioning of the Henry Bennett Centre nurse during the first call; particularly in relation to known risk factors such as Ms Morris' profound deafness, her current mental state and the exact details of the threat to kill.
* The dispatcher's failure to advise the attending officers of the name of the person being threatened.
* The failure to notify the sergeant on duty and all units in the area about the threat.
* Inadequate area enquiries by the attending officers and their failure to seek more information about the person under threat.
* The poor handling of the second call; including a lack of questioning on particular risk factors; and the recording of inaccurate and misleading information, which then led to the key failure to dispatch officers to apprehend Ms Morris.
* The failure to consult a Duly Authorised Officer mental health professional.
POLICE ACCEPT FINDINGS, APOLOGISE TO FAMILY
Police have today apologised to the family of Diane White and have accepted all of the findings of the IPCA report into the circumstances leading up to her death.
Assistant Commissioner Upper North, Allan Boreham, has met with Mrs White's family and apologised on behalf of police.
"Police clearly failed Dianne when she needed us after several individual errors came together on the day that resulted in a situation that had tragic consequences," he said.
"We are deeply sorry for what happened and I've met with her family in person to tell them this. I've also told them about a range of things we've done in the three years since to prevent a similar situation happening again."
Mr Boreham says responding to incidents involving people with mental health issues is often a very complex and challenging area for police officers.
"Notwithstanding that, the sequence of events that occurred in Hamilton that day are a tragic reminder that we have to be at our best at all times, even when dealing with what may initially appear to be routine matters. If not, there is always the risk that things can go very wrong - and this is sadly one of those times. We are very sorry about what happened."
Mr Boreham says police accept all of the findings outlined in the Authority's report, and note that its recommendations echo actions already undertaken by police following its own review of the incident launched immediately afterwards.
"Police reviewed their handling of the incident as soon as it happened and have already initiated many of the actions subsequently identified in today's IPCA report,'' he said.
"While we know that it will not bring Diane back, we want to make sure it does not happen again.
"Whilst the recommendations outlined in the report are important, the key thing that will stop this happening again is the focus of our people, that needs to be clearly on prevention and victims.
"It is clear to me reading this report that if staff at the time had a greater focus on the threat to Diane, we could have done more to protect her and this tragedy could have been averted."
Mr Boreham said among the changes that have been introduced since January 2010 are a new Quality Assurance process for Communications Centre staff, improved training, and technical upgrades to the centre's systems to provide automatic updates to dispatchers.
Police and the Ministry of Health also last year finalised a Memorandum of Understanding that better defines responsibilities and processes to be followed when dealing with incidents involving mental health patients, and police have upgraded their policy on people with mental impairments, which sets out steps for returning mental health patients who are reported missing.
WAIKATO DISTRICT HEALTH BOARD
Waikato District Health Board has concluded that none of its staff involved in Diane White's tragic death acted negligently or unprofessionally.
A statement by the health board said it acknowledges the impact the report will have on Ms White's family, while offering "sincere condolences".
However, it stopped short of apologising for any failings, saying: "There are clearly things that Henry Rongomau Bennett Staff could have done differently in retrospect knowing now what we know about the defendant's state of mind.
"We have spoken to the staff involved about some of those things but no one acted negligently or unprofessionally and no one person could reasonably be held responsible."
The health board also moved to clarify that the social worker described in the IPCA report was not employed by Waikato DHB, but by a non-Government organisation (NGO).
They also added that staff made a "reasonable judgement" to allow Ms Morris to have a cigarette in the courtyard to cool down.
"While in the courtyard, she scaled the fence and staff were unable to stop her. They then contacted the police as described in the authority's report."
