Almost 250 deaths in the Republic that should have been recorded as homicides over a 14-year period were not recorded as such, it has emerged.
It means the Garda underestimated the homicide rate between 2003 and 2016 by 18 per cent; or 234 cases to be precise.
The majority of the new homicides are cases of dangerous driving causing death. However, the Garda had also underestimated the number of manslaughters committed in the State over the 14-year period by 44 per cent.
The new figures, which had been published by the Central Statistics Office (CSO) this morning, show the murder rate has been over estimated by the Garda between 2003 and 2016.
The Garda had recorded 683 cases, but the revised figures is now 680.
That error has arisen because when people went on trial for murder and they were found guilty of manslaughter instead, the Garda did not revisit the cases in its records and change the classification from murder to manslaughter.
The CSO’s revised figures show the rate of manslaughters was under-recorded by the Garda by 41 cases.
The Garda had recorded 94 manslaughters in the period under review. But the revised figure is 135.
The biggest underestimation by the Garda occurred in the dangerous driving causing death category.
The Garda had initially recorded 504 such cases but the revised figure is 700; a difference of 196 cases.
In total, when all homicides between 2003 and 2016 are combined, the Garda had said there were 1,282. But now the revised figure is 1,516; a difference of 234 cases.
The Central Statistics Office last year suspended the publication of any more new crime data when problems emerged with the homicide data.
Today it has begun publishing the data again. And it has also revised the historical homicide figures for every year between 2003 and 2016.
It said in a statement it would resume the publication of the statistics but they would be published under a new category called “under reservation”. It said this category has been applied “to reflect the fact that there are data quality issues in the underlying sources used to compile these statistics.”
The revision has now factored in those cases that were not recorded properly by the Garda. Errors occurred when road deaths that should have been recorded as dangerous driving causing death were recorded as a non-fatal and less serious offence, such as speeding or drink driving.
In other cases when several lives were lost in the same incident of dangerous driving causing death, only one of the deaths was recorded as a homicide.
Errors were also made with other homicides; cases where people were killed in violent circumstances.
For example, some cases of people dying in their home after they were attacked in domestic incidents were recorded in error as non-fatal assaults.
While the CSO has now corrected the homicide figures between 2003 and 2016, more changes in the figures are expected.
A major review is now under way within the Garda into all homicides over the past 15 years. That trawl is much deeper than any examination that has so far taken place. And it is expected it will find more errors.
That review, which is not expected to be completed for another six months, is checking for homicides that were recorded as other less serious crimes in error.
And it is also checking the nature of the investigations carried out into homicides that were incorrectly classified as less serious offences.
The Garda and Minister for Justice Charlie Flanagan has given repeated assurances that even in cases where homicides were not recorded properly, a full and thorough homicide inquiry was conducted.
Just yesterday Assistant Commissioner John Twomey had reiterated that assurance, saying of the cases closely examined so far by the Garda all of the investigations were found to have been conducted properly despite errors in the recording of the crimes.
The Policing Authority has questioned those assurances over recent months and wants to see more research and evidence from the Garda before it accepts the assurances.
A senior CSO statistician this morning defended the decision to resume the publication of statistics despite the concerns.
Olive Loughnane told RTÉ’s Morning Ireland that it had been 12 months since the last statistics were published which had created a vacuum.
Ms Loughnane said the publication “under reservation” was not unique and that crime statistics in both England and Wales also include such a rider. “This indicates that some form of revision is likely,” she said.
She said that the CSO is mandated to provide data and “this is the best available data. We are being transparent about the underlying issues.”
There had been no figures for 2017 and it was important that people realise “how things are moving.”
The next step for the CSO is to engage with an Garda Síochána on the number of crimes that need to be addressed. "We are committed to assisting with that," she added.
Ms Loughnane said that the figures to be released will show “a substantial increase” in the number of homicides. She also acknowledged that the difficulties with homicide statistics were also likely to spread into other crimes.
