Home > The quality of crime statistics.

Guiney, Ciara (2016) The quality of crime statistics. Drugnet Ireland, Issue 58, Summer 2016, pp. 20-21.

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Since 2003 the production of crime statistics has been the responsibility of the Central Statistics Office (CSO). These statistics are based on data collated by An Garda Síochána using the Garda PULSE (Police Using Leading Systems Effectively) system.


In 2014 a report produced by the Garda Inspectorate drew attention to serious problems regarding the recording of crime on PULSE.1 Issues included the non-recording of crimes, lack of timeliness in recording crimes, misclassifying crime incidents and non-crime incidents at initial stages, incorrect reclassification of incidents, and incorrect application of detection and invalidation status to certain crimes.


Given that the CSO draws on PULSE data to produce crime statistics, it was considered essential to carry out a review of the data received by the CSO to determine their accuracy.2 The aim of the review was to determine how many legitimate offences were not being recorded on the Pulse system. Access was provided by the Garda Síochána to crime and non-crime data including CAD (Command Aided Dispatch), paper records and non-crime PULSE incident groups, such as Attention and Complaints, Property Lost and Domestic Dispute. A random selection of CAD and paper records was checked against corresponding records on PULSE. What follows is a summary of the main findings.


Non-recording of crimes

Twenty per cent of validated crimes (e.g. assault, burglary, criminal damage, public damage, robbery, theft) and 23 per cent of non-crimes (e.g. bomb scares, domestic disputes/ domestic violence and sexual assault) reported on CADs were not reported on PULSE. In addition, 16.4 per cent of validated paper records were not reported on PULSE. The authors advised caution when interpreting these results as it was challenging to match records between CAD and PULSE, hence some records deemed not to be on PULSE may actually be there.


Lack of timeliness in recording crimes

Within the PULSE system a creation date and report date are recorded. The CSO found that following a crime being reported, there was a delay of over a week before seven per cent of incidents were recorded on PULSE.


Alteration of narratives

The narrative field on PULSE, which records details of a crime, can be amended as further information becomes available. To determine whether narratives had been edited to justify classification decisions, the narrative lengths of all incidents were analysed to see if any reductions in length had taken place between the January 2012 dataset and the April 2014 dataset, which would indicate unacceptable editing. Not a single case was identified.  


As it was not possible to establish what records had been amended before January 2012, the audit trails for a sample of 500 PULSE criminal records were examined. The audit trail records every change to the narrative, the date and time of the change and who made the change. Only one of the 500 records (a reclassified crime case) revealed evidence that an alteration had been made to justify an incorrect reclassification.


Misclassification of incidents

There are approximately 300 crime classifications on PULSE. How crimes are classified is essential for accurate reporting.


The CSO focused on six classifications of serious crimes – Assault Minor, Assault Causing Harm, Criminal Damages (Not Arson), Theft from Person, Burglary, and Robbery from the Person. The analysis indicated that three per cent of records were classified incorrectly and the classification of a further four per cent was unclear.


To determine whether non-crime incidents should have been classified as crimes, narratives from Attentions and Complaints (n=1,000), Property Lost (n=500) and Domestic Dispute (n=300) were examined. Although the majority of records were classified correctly (91%–94%), a small number of records were either misclassified (4%–7%) or unclear (4%–7%). Further analysis indicated that 69 records from Attention and Complaints should have been in Assaults or Fraud/Threatening Letters and one in Sexual Assault/Robbery; 18 Property Lost should have been in Thefts; and 13 Domestic Dispute should have been in Assaults or Assaults causing Harm.


Incorrect reclassification of crime incidents

Crime classifications were compared on PULSE between January 2012 and January 2013. Three areas were examined: Assault (n=57), Assault Causing Harm (n=12) and Criminal Damage (n=189). The analysis indicated that 71 per cent of reclassifications were justified whilst 15 per cent were not. A further analysis of ‘downgrades’ in the Assault and Assault Causing Harm categories indicated that 51 per cent were justified and 26 per cent were not. Approximately 50 per cent of crimes were upgraded and 15 per cent were reclassified down in the Criminal Damage category. Within this category, the highest proportion of reclassifications occurred for Burglary (44%), followed by Theft (35%).  


In non-crime categories, for example Attention and Complaints, Burglary and Related Offences (19%) and Theft and Related Offences (12%) were reclassified.  A limitation of this analysis was that data from PULSE were only received by the CSO at the end of every month; hence the CSO was not privy to reclassifications that occurred when the crime was originally reported.


Incorrect application of detection status

To determine whether ‘detected’ crimes resulted in criminal proceedings, 138,807 ‘detected’ crimes were examined, 54% were linked to a charge or summons whereas 46% were not. A further analysis of the accuracy of ‘detection rules’ on ‘detected’ crimes with no charge or summons (n=500) indicated that over a third of crimes were wrongly assigned ‘detected’ (35%). This accounted for a 16% (22,307) reduction in the total number of ‘detected’ crimes.


Incorrect application of invalidation status

Invalidation occurred when there was no crime or when ‘counting rules’ were wrongly applied (p.24). Out of 528 invalidated records, 23.1% were unjustified. The highest proportion of unjustified invalidations was shown for ‘Robbery, Extortion and Hijacking Offence’ (18.9%; n=32) and ‘Sexual Offences’ (43.3%; n=26).



The CSO estimated the impact of the problems identified in their review. The largest percentage increases were 38 per cent in Group 03 (Attempts, Threats to Murder, Assaults, Harassments and Related Offences), 27 per cent in Group 08 (Theft and Related Offences) and 26% in Group 09 (Fraud, Deception, and Related Offences). Alterations owing to misclassifications within groups were not considered, for example Assault Causing Harm and Assault minor are both in Group 03.


Consistent with the Garda Inspectorate report, the CSO review found discrepancies between crimes recorded on CAD/Paper and PULSE. The CSO made a number of recommendations to improve the quality of the data.

  • The introduction of a unique identifying number between CAD/Paper reports and PULSE would enable data to be linked more effectively, and allow greater accuracy and quality control.
  • The crime narrative should match subsequent crime classification, detection and/or invalidation status recorded.
  • The decision-making process in PULSE should be centralised. This would ensure operational procedures were followed with regard to crime and non-crime classification, reclassification, detection and/or invalidation.


1 Garda Inspectorate. (2014) Report of the Garda Síochána Inspectorate. Crime investigation. Dublin: Garda Inspectorate. https://www.drugsandalcohol.ie/22967/  

2 Central Statistics Office (2015) Review of the quality of crime statistics: Dublin: Government of Ireland. https://www.drugsandalcohol.ie/24887/

Item Type
Publication Type
Irish-related, Open Access, Article
Drug Type
All substances
Intervention Type
Crime prevention
Issue Title
Issue 58, Summer 2016
August 2016
Page Range
pp. 20-21
Health Research Board
Issue 58, Summer 2016

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