The document summarizes research on the effects of body worn video cameras on police behavior and interactions with the public. A trial conducted by West Midlands Police found that the use of body worn video cameras by patrol officers resulted in a decrease in the number of citizen complaints and use of force incidents, and an increase in the rate of criminal charges compared to when cameras were not worn. Interviews with officers, supervisors, and members of the public indicated that the cameras increased officer confidence and accountability, and led to improved behaviors. However, the effectiveness of body worn video is still limited and more research is still needed.

1. WMP Body Worn Video TrialWMP Body Worn Video
Trial

2. Rapid entry

3. Socio-Cognitive Theory
• In social contexts, knowing that one is being-observed
leads to modifications of behaviour and often into
socially-desirable-responses. [Chartrand & Bargh (1999); Jones &
Nisbett (1971); Wicklund (1975); Paulhus (1988); Munger & Shelby (1989)]
• Deterrence theory predicts that when the perceived
probability of apprehension is high, unacceptable
behavior is less likely to occur. Nagin (2013)

4. Rialto Trial
 Reduction in use-of-force incidents from 61 to 25
 Of the 25 use-of-force incidents , 17 were control and 8 Experiment
 Of the 8 use-of-force incidents on the Experiment days, all 8 were
recorded on video
 Contacts increased from the previous years - no backfiring effect
 Reduction in complaints from 24 to 3 or from 0.7 complaints per
1,000 contacts to 0.07 per 1,000 contacts
 Survey of all officers before and during RCT shows no significant
changes in officers’ self-legitimacy

5. WMP Trial - Hypotheses
Wearing body worn video by patrol officers will:
• Decrease number of recorded incidents of use of force
• Decrease number of citizens complaints
• Increase satisfaction of members of the public coming into contact
with the police
• Improve self-legitimacy of police officers
• Increase rate of prosecution/charge/early guilty plea
Compared to not wearing cameras.

6. Trial Construct
Randomised Control Trial on Birmingham South and
Wolverhampton LPU’s supported by Cambridge University:
• 7 Response teams randomised to shifts
• 160 Officers in trial with no previous use of BWV
• 2 week initial 100% assignment to test systems
• 6 month trial with reviews at 120 days
Running during same period similar trials in West
Yorkshire, Cambridge, PSNI and Sacramento overall
supervision Dr Barak Ariel, Cambridge University.

7. Deployment Protocols
• Trial looked at personal issue (BS) and pool
issue (WV) to response teams
• Compulsory to wear
• Officer discretion to record incident.
• High visibility only, no covert use.
• Only standard response deployment, no Public
Order/Football/Firearms etc.
• Pre-record shut off for trial

8. Process
• All trial officers entered into DEMs software.
• Password/RFID to book out BWV.
• Officer uses for tour of duty
• BWV returned to cradle, automated download, delete and recharge.
• Officers designate data as evidential or non-evidential - Retention
indefinite (evidential) or 30 days (non-evidential).
• Officers can view only their footage with DEMS
• Supervisors can view all officers footage
• One super-user can view and delete any footage.
• Audit log on all footage showing who has viewed, printed, cropped
etc.
• Evidential material burned to DVD prior to end of tour of duty.

9. Birmingham South RCT
• 46 officers across two units randomised to shift
• 430 officer shifts over 6 months
• 592 arrest records, data obtained only for charges so far.
Use of force and court results currently being reviewed.
• 99% compliance with random allocation
• 134 victim interviews completed reviewing perceptions of
BWV.
• Before and after implementation questionnaire with
officers.

10. WMP Interim Results
Complaints
• No complaints registered against two units using
cameras on BS during trial period, compared 10
across other three units.
• 46% reduction in complaints against WV
response officers. (24 to 13)
• Cost saving for investigating complaints £28,000
per annum on two LPU’s. (PwC)

11. WMP Interim Results
Charges
• Overall charges BS – Increase 12% (p 0.014)
• DV incident charges – Increase 13% (BS) No
Change (WV)
• Public Order offence charge – Increase 22%
(BS) 14% (WV)
• Racial incident charge – Increase 12% (BS)

12. User Views
• Increased officer confidence
• “...it’s obvious isn’t it? Present this to a Court and they have to believe you.”
Officer - D Unit
• Increased accountability and changed behaviours
• “... I’m much more confident since viewing some footage my officers are
doing the right thing out there.” Supervisor - B Unit
• Officers used footage as self-reflection tool
• “... When I look back I can see I should have never put myself in some of
those situations, never thought about it before.” Officer - B Unit
• Shortened trials
• “...This footage made the difference to the trial, he changed his plea after it
was shown.” Barrister - Birmingham Crown Court.
• Camera reliability is important...
• “...I want this to back me up, if it isn’t going to work why should I use it?”
Officer - D Unit

13. The Silver Bullet?
• Better evidence
• Increased officer confidence
• Improved behaviours
• Transparency to public
• Improved legitimacy
• Beats public recordings of
officers interactions?
• Effect on use of force still unclear.
• Officers miss start of dynamic incident.
• Strength of evidence unchallenged at
Court.
• Some cameras and software very
poor.
• Evidence of effectiveness still limited

14. Future considerations
• More research....
• Thesis 'Testing the effect of BWV on police Use of
Force.’
• Learning tool/professional development – used in
military, professional sport, business, medicine but not
policing?
• Scrutiny panels – removes need for external assessors
• Reduced time in interviews/statements
• Victim use?
• Live feed for negotiators/firearms commander?