Use of crime and criminal justice
statistics at the national and
international level
Steven Malby
Research Officer
Statistics and Surveys Section
Purpose of crime and criminal justice statistics
“The collection of reliable and comprehensive statistics is of
immense importance to everyone involved with criminal
justice, especially to the criminal justice administrator.”
Statistics on crime and criminal justice help
governments to assess and monitor:
 the conditions, circumstances and trends of
well-being
 social impact of public expenditures and
policies
However, it is only when raw information is
transformed through purposeful collection and
organization into statistical form that individual
records provide valuable information for criminal
justice decision making.
Purpose of crime and criminal justice statistics

Analysis of crime levels and perceptions and experiences of public
safety for policy making
•

Prosecutors may benefit from knowledge of police-recorded crime, including
information on numbers of persons suspected, arrested or cautioned
Monitoring and evaluation of the impact of crime prevention strategies
•
Prosecutors may have access to detailed case information not available at the
law-enforcement level. Comparisons may be made between different
provincial/district prosecutor offices and between sub-categories of suspects,
including children, women, and citizens of other countries

Decisions on allocation of resources

Assessment of the workload and operation of criminal justice system
components and of their efficiency and effectiveness
•
Prosecutors may benefit from analysis of case data at different levels of the
criminal justice system in order to assess the effectiveness of their work
Sources of crime and criminal justice statistics
 Administrative statistics (police, prosecution, courts, prisons)
 Victimization surveys (households, women, businesses)
 Self-report studies (juveniles, prisoners)
 Ad-hoc studies on specific types of crime, such as organized crime,
trafficking in persons)
Definition
Counting
Unit
Institution
Number of crimes recorded
Incidents
Law enforcement
Number of persons arrested
Persons
Law enforcement
Number of persons prosecuted
Persons
Prosecution
Number of persons convicted
Persons
Courts
Number of persons detained
Persons
Prisons
Distribution of
responsibility
may vary
depending upon
the specific
national criminal
justice system
From operational systems to statistical systems
Central
Police
Command
Case file
Police
Attorney
General
Case file
Prosecution
High
Court
Court file
Courts
Ministry of
Justice/Interior
Logs/prison files
Detention
* System represents a generic example criminal justice system and does not correspond to that of any individual country.
Data collection by the United Nations
• The United Nations Survey of Crime Trends and
Operations of Criminal Justice Systems (UN-CTS)

Tenth UN-CTS covered
the period 2005-2006
 Consists of four parts –
Police, Prosecution,
Courts and Prisons
 Each part completed by
the relevant institution
Responses to the UN-CTS
Responses to the Tenth UN-CTS, by part
Number of respondents by Part
Percent of numerical items completed
Analysis of UN-CTS data
 Cross-national analysis of data presents a number of challenges,
including different national case recording/counting rules, different
crime definitions and different criminal justice system crime ‘priorities’
 UNODC attempts to address these challenges through provision of
metadata that assists users in establishing data quality and
comparability across time and countries
• Selected data reviewed for:
 Consistency of responses with previous CTS waves (trend analysis)
 Internal consistency of responses within Tenth CTS
 Consistency of response with other known crime statistics sources
Dissemination and analysis of UN-CTS data
• Data from Tenth CTS presented in two formats at unodc.org:
 Values and rates annotated with extended UNODC metadata for selected
variables (to date – police-recorded homicide)
 Values and rates for all CTS variables reproduced as received, including
prosecution data
What can the data tell us?
• Same set of countries across
time series
• Crime rates ‘normalized’ to
base of ‘100’ in order to
display trend only
• Crime types that show
significant variation in
definition (such as assault) not
included in analysis
200
150
Basis:
100
1995 = 100
50
0
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
Trends in selected categories of
police-recorded conventional
crime, 1995-2006
Intentional homicide (14 countries)
Robbery (15 countries)
Burglary (10 countries)
Drug-related crime (14 countries)
Automobile theft (14 countries)
Attrition analysis of homicide in the UN-CTS
1400
Suspected, arrested or cautioned
1200
Prosecuted
1000
Convicted
• Prosecutors may play
different roles in case
initiation and
subsequent case
recording
800
600
400
200
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Criminal justice system attrition for intentional homicide (4 year average 03-06)
• UN-CTS attrition data
does not represent the
same cohort of cases
and is challenging to
analyse due to
differences in national
systems
• ‘Backlogs’ may affect
ratios between different
parts of the system
although, to some
extent, this is corrected
for by use of an average
over time
Measuring criminal justice system performance?
 Careful combination of
victimization survey and
administrative statistics may
allow analysis of criminal justice
system ‘attrition’ rates for
selected crimes
 Other measures require the
capacity to follow a ‘cohort’ of
cases, rather than attrition
analysis at the macro level
 This may represent a challenge
where different components of
the criminal justice system adopt
different approaches to case
recording, particularly in light of
different prosecutorial roles
Data may be obtained from prosecution or
court depending upon nature of national
criminal justice system
UNODC research and use of cross-national
prosecution data
under UNSCR
1244
Future directions
 UNODC Expert Group Meeting in January 2009 recommended that, in
order to enhance knowledge of thematic and cross-sectoral trends in
specific crime issues:
• The UN-CTS questionnaire should be revised in order to improve
response rate, produce more timely data and to minimize the reporting
burden and complexity for Member States
• This should be achieved through a reduced questionnaire containing a
core set of questions with annual periodicity, together with an ad-hoc
thematic module which would change every year
• A network of national contact points for crime and criminal justice statistics
should be established. The network should include contact points in
national statistical offices, law enforcement, prosecution, courts and
national penal administrations
Conclusions
 Crime and criminal justice data from the system as a whole may be
important to prosecutors for reasons of policy analysis, assessment of
effectiveness, and workload management
 Data at the prosecution level is important both for analysis of criminal
justice system performance and providing disaggregated data (eg. final
classification of criminal offence or details of nature of the offence) that
may not be available at the law-enforcement level
 The UN-CTS focuses both on crime and operation of criminal justice
systems. Prosecution data is crucial to a full understanding of the
response of society to different forms of crime
 Appointment of focal points within national offices of the prosecutor will
be key to effective reporting of data at the international level
Thank you for your attention
sass.crime@unodc.org
Statistics and Surveys Section
Policy Analysis and Research Branch