The 2007 Bazley report into police sexual misconduct threw some most welcome light on unsavoury, indeed criminal, behaviour by a small minority within the force, but it also disclosed to the wider public, probably for the first time in recent memory, the extraordinary disconnect that had been allowed to develop between police senior management and the great majority of officers who serve the public so faithfully and well.
That inquiry found 313 historic complaints of sexual assault against 222 police officers, 141 of which had enough evidence to warrant criminal charges or disciplinary action.
It could not be construed as other than coincidental that senior management in the force until very recently largely included officers from the period studied by Dame Margaret Bazley.
The new Government's Minister of Police, Judith Collins, having been a strong critic of errant police culture during her time in Opposition, took up the challenge to do something about improving matters, warning the senior commissioners to step up their game and speed up the "culture change" so clearly outlined in the Bazley report.
The Office of the Auditor-general also made several formal recommendations to meet these needs last year, noting the police were at a "critical point", that the mass of officers needed to understand and support the need for change, and that there was a risk progress would stall.
Mrs Collins remained, it seems, unconvinced by police assurances: there was still "a lot of work to be done, particularly at senior level, to make sure that everyone is held to very high standards".
The pace of change was too slow to plug the gaps in the new police code of conduct.
Taxpayers will today wonder what the problem is: surely no further ink still needs to be spilled on this matter? It seems it does.
An independent report on progress in meeting the recommendations of the Bazley report, published this week, provides little confidence that the police even at the highest levels are intolerant of poor performance and sexual misconduct within the service.
The PricewaterhouseCoopers report, though littered with jargon, makes it sufficiently clear senior management had implemented some measures to achieve what is called "technical compliance", but fundamental cultural change had not occurred, with "inconsistency in management style, quality and practice at all levels in police and across police districts".
It describes some officers as still "poisoning the well" - a clear indication of management failure.
For his part, Police Commissioner Howard Broad - who must shoulder the responsibility for the present state of the police - is being defensive, claiming progress has been made but that "enduring change" will take time, and fresh legs and renewed effort are needed.
More than 50 staff had left for bad behaviour in the past two years but there were still people who had not accepted the Bazley report, let alone its recommendations.
It is especially noteworthy that the PricewaterhouseCoopers report refers to change at the police college and the training service centre not going far enough, describing some staff as inappropriate role models.
If this is indeed the case - in a situation where it is vital the attitude changes required need to be impressed on new recruits - then the police have a long way to go.
Mrs Collins cannot wave much of a practical political big stick at the police.
The evidence implies, however, that behind-the-scenes pressure has been applied.
Mr Broad was entitled to seek a further five-year term as commissioner, but chose to retire with effect from April.
She has replaced him with a man generally regarded as an "outsider", Peter Marshall.
In announcing this decision, Mrs Collins said the Bazley recommendations would be a high priority when she considered the position of deputy commissioner, also due for replacement or renewal in April.
The present deputy commissioner, Rob Pope, appointed at the same time as Mr Broad, having been passed over for the commissioner's job, has also chosen to leave the service - no surprise given the Minister's unsubtle signals.
All institutions with great power from time to time develop periods where their separation from normality and the people they serve becomes entrenched and self-protective, a house within a house, and become answerable only to their own informal conventions and ways of doing things - their own "culture".
We have seen it in the army, with the occasional scandals involving the maltreatment of cadets, and in the navy on the introduction of female crew.
The police have been no different.
The desire to build absolute confidence in one another, to construct an allegiance of absolute loyalty to fellow members, can lead to a blindness to faults.
Clearly, the police have still to fully open their own eyes.
