A major review by the police watchdog into how it investigates deaths in custody has found strong criticism of how it engages with bereaved families, with many saying that they felt like they were under investigation.
The wide-ranging report by the Independent Police Complaints Commission (IPCC) said families complained of a lack of "empathy, sensitivity and compassion", while some "felt that they and those who had died were wrongly characterised or unfairly judged".
Concerns about the watchdog's approach in identifying whether discriminatory behaviour might have been a contributing factor in a death were also raised, with respondents identifying a need for better training for IPCC staff on diversity issues, particularly in relation to race and ethnicity, mental health, and learning disabilities.
The 111-page report notes that m ental health is a major underlying issue in many deaths investigated by the IPCC, with approximately half of all those who died in police custody in 2012/13, and almost two-thirds of those who apparently took their own lives afterwards, being known to have mental health concerns.
Publishing its findings today, the watchdog also conceded that c oncerns were raised about "insufficient attention to detail and a failure to gather and collate all evidence or to pursue all reasonable lines of enquiry".
"Families, their representatives and police officers criticised us for taking too long to complete investigations, leading to added stress for all involved," the report added.
It has set out a raft of actions it plans to take to improve procedures, including making police officers attend witness interviews as soon as is possible after the incident. Another finding of the report was the perception that the police receive more favourable treatment than members of the public.
Among those who contributed to the review was the charity Inquest, which said the report was "welcome acknowledgement that time and again bereaved families have been failed by the IPCC".
Its co-director Deborah Coles said: "T he absence of a robust police watchdog has allowed corruption and dangerous practices to go unchecked. Family and public confidence will only be achieved if the IPCC delivers an investigation process that ensures wrongdoing, misconduct and poor practice is uncovered and police are properly held to account.
"This is a pivotal moment for the IPCC and they must make this happen to match these reasonable expectations. Whether they can remains to be seen."
Families of some of the people who have died in police custody also welcomed the report, but said they awaited the changes being put into action.
Marcia Rigg, whose brother Sean Rigg died in police custody in Brixton, south London, in 2008, said: " We hope that all the recommendations are implemented without delay, and that as well as helping us the review will help other families and lead to effective change in the way deaths in police custody are investigated."
The IPCC said that "s ome of the strongest criticism" during the review was about the way it engaged with families and in light of this, it was now providing training on bereavement awareness and grief to all investigators and commissioners. The watchdog said it would also strive to better involve families with the investigation by keeping them updated and giving them the opportunity to ask questions at every stage.
Other complaints that were taken into account included relatives "being overwhelmed with information", while investigators often failed to take account of their needs and expectations.
"Families explained that negative experiences made family members suspicious of the IPCC and doubtful about the organisation's capacity to carry out an effective investigation," the report said. However, it added that s ome did report examples of good practice in its engagement with them.
With reference to issues of discrimination the watchdog said it would, in all cases, consider whether this required investigation, while it was providing ongoing refresher training for both investigators and casework managers on dealing with allegations of discrimination.
It also said it was taking steps to increase its staff's knowledge and awareness about current mental health issues and would review its guidance to police.
The IPCC said it welcomed the recent change to the law that requires officers to attend witness interviews but noted that in some cases, police and staff are being advised by the Police Federation or their legal representatives to attend but not answer questions, which it does not have the power to overrule.
The report went on: "We expect police officers and staff, as public servants, to cooperate fully with our investigations and our search for the truth. It is unacceptable that some officers who are immediate witnesses to a death during or following police contact do not answer questions at interview and therefore appear reluctant to cooperate fully with our investigation."
The IPCC said there was "no doubt" that a reduction in its resources coupled with an increase in demand has put a strain on the speed and quality of investigations, but added that "even within our current resources, we must provide the best service possible".
Dame Anne Owers, chair of the IPCC, said the watchdog would be reporting on progress in six months' time.
She said: "This publication of this report has come at a critical time for the IPCC, as we begin a period of major change and growth. This review has helped to guide the changes we have already made and those that we are planning.
"But these changes are not just about processes and guidance. They need to be rooted in a culture of independence and quality assurance, recognising that those directly affected are at the heart of what we do.
"This is also to the benefit of the police themselves - it is clear that, if people do not trust our independence and effectiveness, they will not trust the police service either."