Testing the effect of BWV in the WMP: An RCT

Randomised Control Trial Status


Trial Hypothesis

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.

Geographical area

​Birmingham South and Wolverhampton LPU's WMP.

Research Institution / Organisation

University of Cambridge

In Collaboration With

West Midlands Police

Project Start Date

May 2014

Participants - inclusion criteria

​Response officers both LPU's.
BS - Two units - personal issue
WV - Five Units - pool issue

Target Sample Size

​430 officer shifts.

Study Design

​Level 5 Maryland Scale - RCT


​Randomised shifts, experimental shifts assigned by Cambridge monthly Cameras/No Cameras.

Outcome Measures

​1. No of Complaints
2. No of inxcidents of use of force
3. No of arrests
4. No of charges
5. No of early guilty pleas at Court
6. Survey data from officers before and after
7. Survey data from victims.

Summary of Findings

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)
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)

Further data on use of force, ealry guilty pleas and results of 150 questionnaires awaited.
Racial incident charge – Increase 12% (BS)

Final report: Testing the Effects of Body Worn Video on Police Use of Force during Arrest: A Randomised Controlled Trial

Date last updated

Tuesday 23 June 2020
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