An Garda Síochána has shown itself to be not very good at counting. The breath tests fiasco was the most damaging example. The Acting Garda Commissioner drew a line under that controversy last year and since then the police service has tried to move on.

However, the ongoing controversy over the miscalculation and misclassification of crime statistics continues to dash any such misplaced hopes.

It once again calls into question not simply the Garda's ability to count, but also its culture, its attitude to whistleblowers, such as the garda analysts Lois West and Laura Galligan, and its ability to identify, record and ultimately tackle crime.

The Central Statistics Office is due to recommence publishing garda crime figures next Wednesday for the first time in over a year. It is, however, for the first time ever introducing a new category, ominously titled "Under Reservation".

The CSO cannot yet say exactly what that means but it does not sound good. Its statistician, Olive Loughnane, described the category as comprising a "quality of material that is different to other output we produce; it doesn’t meet the standard".

In other words, the statistics in this category are unreliable and undependable. However, as regards an indication of some crime rates and trends, they are "the best possible available information; they are all we’ve got".

Homicide comprises four categories of crime; infanticide, dangerous driving causing death, manslaughter and murder. Murder is the most serious crime on the statute book. The difference between murder and manslaughter can be the difference between a suspended sentence and one of life in prison.

It is not difficult to see why the categorisation of such a crime is so important and why crime categorisation in general is so important, not simply for statistical accuracy but also for crime investigation, resource and budget allocation, policing policy, and the public good.

At its most simple, it is clearly important that we know how many people die violently and how they die.

There is a vast difference in the circumstances of death, for example, between a gangland murder and an incident where a drunk driver knocks down and kills a pedestrian. The grief and pain of the families and friends left behind may be equally severe, but they do have a right to know how their loved ones died.

There's no doubt that next Wednesday’s crime figures will show there were more homicides over the past 15 years than was previously thought. Deaths from driving incidents and assaults that should have been recorded as homicides were not reclassified after the criminal investigations and court cases had been completed.

The rules for counting homicides were not adhered to and have not been for quite a long time.

It's five years since a serving garda in his role as President of the Garda Representative Association warned that the Garda’s crime figures could not be relied on.

In April 2013, John Parker said break-ins were being recorded as the less serious offence of criminal damage and not burglary if nothing was stolen. In cases where a victim declined to make a statement, in the eyes of the Garda no crime took place because no offence was recorded.

These practices made it look like burglaries weren't as widespread and there weren't as many crime victims as there actually were. As John Parker pointed out at the time, the figures could also be "massaged" the other way.

For example, instead of doing one checkpoint at one location for 30 minutes, gardaí could do two checkpoints for 15 minutes at two locations and appear to double their productivity.

Mr Parker’s comments were widely reported on radio, television, online and in the newspapers and then ignored. He was effectively told by management to "put up or shut up" and the matter was closed along with the 2013 annual conference of the Garda Representative Association.

However, other organisations were to follow the GRA's lead in publicly voicing disbelief over the garda crime figures and instead of relying on anecdotal evidence, they came armed with facts that could no longer be ignored.

The CSO first lost confidence in the garda figures after it found that almost 20% of crimes reported to gardaí were not recorded on its PULSE system. The CSO stopped publishing the figures for a time in 2014, subsequently resumed with a health warning, but stopped again in March of last year.

In November 2014, the Garda Inspectorate found that serious crimes such as assault, burglary, robbery and theft were being "under-recorded" by as much as 30% in some garda divisions. It found 45% of domestic violence calls to gardaí were not being recorded at all.

The Policing Authority also became involved and five years after crime statistics first became controversial, it is still not happy. Its chairperson told the Oireachtas Justice Committee this week that "this has been the most frustrating and troubling piece of work in which the authority has engaged".

It has been trying to get answers for the past year, but as Josephine Feehily put it, "we are still not finished and we are still not satisfied".

Of 41 cases of homicide reviewed by gardaí, 12 of those have been reclassified upwards. Those families have been contacted.

There are 16 more cases that have had some change made to their classification and the PULSE system has been updated. Another 13 remain unchanged.

The CSO has now reviewed the garda crime figures in relation to homicides back as far as 2003. It says it will publish comparative statistics and graphs showing what the figures originally looked like and what they should have looked like.

It has, in conjunction with the garda data quality team, looked at more than 1,200 homicides and found major discrepancies.

We, therefore, now know that mistakes have been made in the recording of homicides and that revisions have been made. We also know that the full extent of the mistakes has not yet been identified. The issue has not yet been resolved.

The Policing Authority says it is mindful that it must strike a careful balance between challenging and undermining An Garda Síochána, and transparency and concern for victims and families.

It accepts that very often gardaí are skilled investigators more focused on solving the crimes rather than accurately recording the outcomes.

Ms Feehily also says that much of its detailed work has been carried out in private because it does not want to prematurely or unnecessarily alarm families.

The problem, however, for those families in particular is that this issue is now one of major public concern.

The CSO has also conducted its work for the past year in private but next Wednesday its report will be made public. It's likely to prove grim reading.