Officers were found guilty of misconduct in Louise Webster's case
Stronger police accountability has been called for after a BBC Panorama investigation found that officers accused of misconduct were being allowed to quietly resign rather than face the disciplinary process.
Responses to freedom of information requests from 47 of the UK's 53 police forces found that between 2008 and 2010, at least 489 officers facing misconduct allegations were able to quietly walk away.
Lawyer Jocelyn Cockburn, who specialises in cases involving complaints against police, said this so-called "back door" carries hidden risk.
"If they are allowed to leave the police without any stain on their character then there is the chance they will go and work in another force and that does happen," she said.
Greater Manchester Police Chief Constable Peter Fahy, speaking for the Association of Chief Police Officers (Acpo), said police resignations in the face of misconduct allegations can be in the public interest.
"There is a judgement about, do you want to wait for a long drawn out disciplinary procedure, which you know is likely to end in the officer losing their job, or if that officer is willing to resign, is it not in the public interest again, to get them off the payroll and to avoid the cost and expense of a hearing?"
The programme also found that there were 1,915 guilty findings against officers for misconduct during the same period.
One fifth of officers against whom punishments were handed down - or 382 in total - were dismissed or required to resign.
Some of those who complained about police misconduct are now calling for greater transparency in the way the police are regulated and how punishments are handed out.
In 2010, brother and sister Aaron Williams and Hayleigh Webster called police when their mother, Louise Webster, was stabbed in front of them by her partner.
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Richard Bilton presents Panorama: Cops Behaving Badly
BBC One, Monday, 31 October at 8.30pm
Despite their frantic calls for help, police did not arrive until 19 minutes after the first 999 call - even though two officers were in the immediate area (and did not attend the call).
While medical experts concluded that Ms Webster's life could not have been saved - and the courts jailed her partner for life for her murder, a subsequent investigation by the Independent Police Complaints Commission (IPCC) found that the officers had failed in their sworn duty to protect life or at least attempt to do so.
The Northamptonshire force concluded it was a case of gross misconduct - which the IPCC defines as behaviour for which an officer is likely to lose his or her job.
At a hearing that was not open to the public or the media - but which family were allowed to attend - two senior officers and an independent person appointed by the local police authority decided both officers could keep their jobs and they received final written warnings.
Ms Webster's father, Steve Webster, said the punishment was inadequate: "If they're not doing their job properly then there should have been some other form of punishment, surely."
Hayleigh Webster said she felt she and her brother were left on their own in a house with the attacker, trying to save their mother's life.
"They should have lost their jobs because of it. If they couldn't turn up to something so important like that, then what are they actually going to turn up to?"
In most misconduct cases against the police, local forces investigate themselves.
Misconduct: The Numbers
Findings of guilt for misconduct: 1,915
Dismissed or told to resign as a result: 382
Further cases where officer resigned or retired without facing discipline process: 489
Source: Freedom of Information responses from 47 of 53 UK forces for 2008-2010
The IPCC handles public complaints and only plays a role in very few, serious misconduct cases - usually involving death or serious injury.
While it can make a finding of misconduct, it does not hold the power to punish - that is handed back to the officer's own force.
Deborah Glass, deputy chair of the IPCC, said: "There is no overall body that has responsibility for the police misconduct system other than the Home Office, I dare say."
She added that local police authorities play a role in the process and offer a measure of accountability but the lack of a single national overview does have an effect.
"I think it makes consistency a problem, guidance can be a problem and I think it does have an impact on public confidence."
But Acpo's Peter Fahy said that while there might not be formal national oversight, local forces across the UK do keep the IPCC informed of developments with misconduct cases and local panels that mete out punishment take their duty to the public very seriously.
"The police authorities locally absolutely oversee what is happening; they are aware of all the cases, they are aware of the complaints, they take it very seriously."
Panorama: Cops Behaving Badly, BBC One, Monday, 31 October at 20:30 and then available in the UK on the