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Crime Detection Rates

    These statistics are categorised as Under Reservation. This categorisation indicates that the quality of these statistics do not meet the standards required of official statistics published by the CSO.

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The crime incident detection rate is the number of detected incidents divided by the number of recorded incidents. The proportion of crime incidents reported in 2019, which were detected by 1st September 2020, varies considerably by crime incident type, from a high of 87.9% of Group 10 (Controlled drug offences) incidents to a low of 12.0% of Group 02 (Sexual offences) incidents. Both figures represent a marginal increase on the equivalent initial detection rates for 2018 incidents published last year; +1 percentage point for Sexual offences, and +2.6 percentage points for Controlled drug offences.

A crime is considered detected when AGS have identified and sanctioned a suspected offender for the crime. Valid sanctions may include charges and summons, formal and informal cautions, and fixed penalties depending on the offence type. There are some limited circumstances where a detection is permitted even though no suspected offender has been sanctioned. The rules governing crime incident detection are outlined in the Guide to How Crime is Recorded and Counted by An Garda Síochána.

The time gap between an offence being recorded and a suspected offender being sanctioned is influenced by a variety of factors (e.g. gathering evidence, awaiting laboratory results or awaiting a direction for prosecution), and varies by crime offence type. Hence, crime incident detection rates tend to increase over time before settling. This may take longer than a year for some crime types.

Recorded Crime Detection 2019 publishes ‘initial’ crime incident detection rates for crime incidents recorded in 2019 based on data extracted on the 1st September 2020. See Table 3.1. The gap of eight months following the end of the reference year has been selected to allow publication of statistics in a timely manner while recognising that reasonable time must be allowed for investigations to reach conclusion and for detection rates to begin to settle. The ‘initial’ crime incident detection rates for 2018 incidents, as published last year, are included in Table 1.1 for convenient reference and comparison.

‘Updated’ detection rates for crime incidents recorded in 2018 are also published in Table 3.1. These figures are based on the latest available data. In this case, twenty months have passed since the end of the reference period, allowing more time for additional crimes to become detected. The difference between the 'initial' and 'updated' figure for crimes reported in 2018 reflects additional crimes which were detected between September 2019 and September 2020. This is an important feature in understanding these statistics.

Two thirds of 2019 homicide incidents detected

The detection rate for Group 01 (Homicide) incidents reported in 2019 (65.5%) was lower than the initial detection rate for 2018 incidents reported last year (75.3%). The detection rate for 2018 incidents increased when measured in September 2020 (78.3%) compared to when measured in September 2019 (75.3%). Approximately three in five (60.5%) incidents in Groups 01a-01c (Murder, manslaughter, infanticide) reported in 2019 had been detected by the start of September 2020, while a suspected offender had been sanctioned in almost four in five (76.5%) of incidents in Group 01d (Dangerous driving leading to death). See Table 3.1.

The detection rate for Group 02 (Sexual offences) incidents reported in 2019 (12.0%) was marginally higher than the initial detection rate for 2018 incidents reported last year (11.0%). The detection rate for Group 02 (Sexual offences) reported in 2018 rose by nearly 8 percentage points between September 2019 and September 2020 to 18.7%, meaning that a suspected offender had been sanctioned in almost one in five such incidents. The detection rates for Groups 02a-02e (Rape and sexual assault) incidents were 12% for 2019 incidents and 19.5% for 2018 incidents, based on the most recent data available. It's important to note that the 2018 incidents in this case are based on more time allowed for detection (20 months after the end of 2018 compared to 8 months after the end of 2019). See Table 3.1.

A suspected offender sanctioned in one third of reported assaults in 2019

Almost one in three (33.0%) incidents in Group 03 (Attempts/threats to murder, assaults, harassments and related offences) in 2019 were detected, and within this group, the detection rate for 03c (Assault causing harm, poisoning) was the highest (43.4%). More than two in five (42.0%) of incidents classified as 06a (Robbery of an establishment or institution) in 2019 were detected, while over one in five (22.4%) of incidents in Group 06c (Robbery from the person) were detected. See Table 3.1.

Slightly less than 15% of Group 07 (Burglary and related offences) in 2019 had been detected by the beginning of September 2020, and around one in three incidents (32.8%) of Group 08 (Theft and related offences) incidents. See Table 3.1.

The detection rate for crimes in Group 10 (Controlled drug offences) for 2019 stood at 87.9%, and an offender had been sanctioned in more than four out of five (84.0%) recorded incidents in Group 13 (Public order and other social code offences). See Table 3.1.

Show Table: Table 3.1 Crime incident detection rates for crimes reported in 2018 and 2019, classified by crime offence group

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Crime incident detection rates tend to increase over time. Detection rates for incidents recorded early in the reference year tend to be higher than those recorded late in the reference year, since there has been more time for the investigations to reach a conclusion. The difference in detection rates from early in the year to late in the year varies by offence type, and some care should be taken when interpreting figures from offence groups where the absolute numbers are low, for example in Group 01 (Homicide) and Group 05 (Kidnapping and related offences). See Table 3.2 and Figure 3.1.

The measured detection rate for Group 02 (Sexual offences) incidents reported in 2019 decreased incrementally from 15.0% of incidents reported in Q1 to 7.4% of incidents reported in Q4. See Table 3.2

The measured detection rate for Group 10 (Controlled drug offences) in 2019 fell from 90.5% of incidents reported in Q1 to 80.7% of incidents reported in Q4. The detection rate for incidents in Group 13 (Public order and other social code offences) was consistent around 84% for each of the four quarters of 2019. See Table 3.2.

Show Table: Table 3.2 Detection rates for crimes reported classified by offence group and quarter

X-axis labelQ1Q2Q3Q4
01 Homicide Offences45.570.67563.6
02 Sexual Offences1514.110.57.4
03 Attempts/threats to murder, assaults, harassments and related offences34.432.533.631.5
05 Kidnapping and related offences29.626.122.023.5
07 Burglary and related Offences13.816.616.811.9
08 Theft and related Offences33.434.133.130.8
10 Controlled drug Offences90.590.788.780.7
12 Damage to property and to the environment20.220.622.118.4
13 Public order and other social code offences8484.483.784

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