An introduction to evidence based policing

1. Evidence Based Policing
“Police practices should be based on scientific
evidence about what works best”
Lawrence Sherman (1998)

2. Definition
Evidence based policing (EBP):
a research approach that focuses attention on both the methods used
to conduct research as on how research findings will later be used by
police agencies.
The goal of EBP? To develop quality research to answer the question
‘what works?’ in order to develop sound policing strategies, policies
and/or programs.

3. Origins of EBP
EBP was developed by Lawrence Sherman (1998).
Sherman spent years studying policing innovations in
the field. Looking at what was going on in the police world, he noted many
policing programs were built on un-tested assumptions (experience, anecdote,
etc.). He turned to the science of medicine for inspiration in developing a new
body of policing research.
In medicine, new clinical treatments are tested using a scientific method known
as the ‘randomized control trial.’
For Sherman, policing strategies aimed at crime problems related to specific
types of offenders, victims and/or places should ideally be tested using
randomized control trials.

4. Randomized control trial (RCT)

5. The Triple T strategy
In 2013 Sherman incorporated his ‘triple T’ strategy into EBP. The 3 Ts are:
• Targeting – identifying a high priority policing problem (ie. a place, crime
pattern, type of offense)
• Testing – police strategies to fix the problem should
be tested through scientific research to make sure they
work (ie. reduce crime, increase arrests, improve
community satisfaction).
• Tracking – once in place, solutions should be tracked over time to ensure
they continue to work and, when needed, to make changes.

6. EBP key element #1:
Research must be ‘usable’
Sherman also believes that research should produce findings that
police agencies can easily adopt and use in their everyday practices.
Two ways to make research ‘actionable’ or ‘usable’ are:
• 1. to incorporate police knowledge and experience into the research
design and process
• 2. for researchers to make their work easily accessible for use by
police practitioners (both in terms of the style of writing and in
relation to where they place their research).

7. EBP key element #2: police involvement
EBP incorporates the police in the research process.
Police officers can be involved in many ways:
- as co-creators of projects (helping to develop topics, research
questions, refine methods, etc.)
- as co-investigators on research teams (conducting research and/or
analyzing results)
- serve as advisors during the research process (providing advice
and feedback while projects are ongoing)
- and/or provide crucial feedback on study results and
recommendations.

8. Three benefits to including police in research
Benefit #1:
Policing researchers can learn from the experience and knowledge of
the police officers with whom they work, including administrative, legal
and other rules that shape their work environment and how to
navigate police occupational culture, among others.
Knowledge acquired from police can inform research decisions that
directly impact the potential success or failure of a study, as well as the
ability of police to later use the results of a study in shaping their work.

9. Benefit #2:
Police officers who become involved in research learn more about the
research process and how research can inform their work.
Participating police officers can therefore become more adept at
commissioning, participating in and using research.

10. Benefit #3
Police involvement in research increases the
potential for the creation of internal change
agents within an organization.
Internal change agents are actors who can skillfully argue for the value
in adopting a tested strategy or practice.

11. EBP key element #3: ‘What works?’
• EBP practitioners are very much concerned with
building an evidence base – that is, with looking
at all available research to find out
‘what works’ to address particular crimes, offenders,
social problems, etc.
• They believe the best way to discover ‘what works’
is to systematically evaluate all of the available research
on a particular strategy or program.
• Such evaluations can provide information
as to the generalizability of research findings

12. Example: sobriety checkpoints
Research on sobriety checkpoints consistently finds they reduce rates
of alcohol related deaths and injuries on the roads.
In other words, the research says sobriety check programs ‘work’ and,
in theory, they ‘work’ everywhere (subject to the need to make some
small changes to account for local conditions and resources).
Therefore, if police want to cut road accidents during the holiday
season, setting up checkpoints is a good idea.

13. Tools to help understand ‘what works’
Researchers in the U.S. and U.K. have created two different tools to
help police and others more easily discover ‘what works’ according to
the research literature. These are:
• The Matrix
• The Crime Reduction Toolkit

14. The Matrix
• The researchers who developed the Matrix
reviewed scientific studies testing whether a police
strategy works or not.
• Each strategy is grouped according to whether the target is an individual,
group, and/or neighborhood, micro-place, nation-state, etc.
• Researchers also determine whether the intervention is general (reactive)
or focused (highly proactive).
• All of this information is then placed onto a chart (next slide)

15. The Matrix

16. Matrix cont’d
With the Matrix, the researchers decide which studies they will include
and only those studies appear on the Matrix table. Included studies
must:
• Be a randomized control trial, quasi-experiment using matched
comparison groups or multivariate controls;
• Be a police intervention;
• Measure effects on crime or disorder as an outcome.

17. EMMIE
In the U.K. researchers developed a system that allows
others to evaluate research literature – EMMIE
• E - effect direction and size produced and the confidence
that should be placed on that estimate
• M - mechanisms/mediators activated by the intervention studied
• M - moderators/contexts related to any intended and major unintended
effects
• I –sources of success or failure in implementing the intervention
• E - economic costs and benefits associated with the policy, practice or
program
EMMIE was used by the U.K. College of Policing to develop their ‘what works
crime reduction toolkit’

18. EMMIE and the ‘crime reduction toolkit’

19. Issue #1: How to decide which method to use?
- Most EBP practitioners today recommend the selection of research methods
that are best suited to answering the question of ‘what works’ in a given
situation.
- To do this matching successfully, they also believe, requires working
collaboratively with police partners, who will best understand not only the
administrative and/or institutional landscape, but also how to work within local
police culture.

20. Other types of methods in use in EBP
Aside from RCTs, EBP practitioners use many different types of research
methods, including:
• Crime mapping
• Surveys
• Qualitative interviews
• Observational field research
• Systematic literature reviews
• Mixed methods (combined quantitative and qualitative approaches)

21. Issue #2: What kinds of topics can EBP be used to research?
Answer: any topic related to policing and/or community safety. Some
examples:
• Domestic abuse programs
• Body worn cameras
• Victim contact programs
• Offender diversion programs
• Traffic safety initiatives
• Police workload issues
• Foot patrol
• Peer support programs for police officers
• Prioritization strategies for offender targeting
• Hot spot policing

22. Summing up
4 key ideas embodied in EBP:
• 1. scientific research has a role to play in developing effective and
efficient policing programs;
• 2. research produced must meet standards of methodological rigor
and be useful to policing;
• 3. results should be easily translatable into everyday police practice
and policy, and;
• 4. research should be the outcome of a blending of police experience
with academic research skills.

23. Thank-you!