The impact of police Body Worn Video evidence on criminal justice outcomes

Research Institution / Organisation

College of Policing

Principal Researcher

Catherine Owens

Level of Research

Professional / Work-based

Project Start Date

October 2016

Research Context

​The College of Policing has been involved in evaluating two Body Worn Video (BWV) trials in conjunction with the Metropolitan Police Service (MPS), the Mayor’s Office for Policing and Crime, and Essex Police. Randomised control trials (RCTs) were conducted in the two forces (MPS May 2014-April 2015, Essex January-May 2014), with teams randomly selected for camera allocation, and other teams receiving no camera in the MPS and cameras randomly distributed to officers in Essex. The evaluation of the MPS RCT was published in November 2015 and the Essex RCT in October 2014. These evaluations covered initial criminal justice outcomes (such as arrests and charges) however no other criminal justice outcome data was used.

This new piece of research continues the evaluations by assessing the impact of BWV evidence on further outcomes including guilty plea, bail/remand and court outcomes (hearing times/sittings, effectiveness of trials, sentences, etc). We are currently unsure whether strict RCT data will be used for analysis and therefore this project has been logged as a generic research project until such time we have confirmed how the data will be analysed.

We plan to supplement this research with a small number of interviews with key stakeholders and also observations of court cases. These final elements apply to London BWV cases only.

Research Methodology

​The quantitative analysis of outcome data will involve case level information relating to a maximum of 50,000 cases. The analysis plan will be finalised once the data are received however techniques such as logistic and linear regression are likely to be used using SPSS software. Analysis will be conducted separately on the MPS and Essex data, split between treatment and control groups however sub group analysis will also be used including; court type (mags/CC), borough and team (MPS only), offence type, disposal type, plea type.

Court observations will be documented where possible. Any key observations and themes will be summarised by the researcher in attendance and analysed to identify key themes. Qualitative interviews with stakeholders will use a semi-structured topic guide in order to ensure coverage of key questions/themes. Interviews will be transcribed and coded in order to inform a summary of findings.

Interim reports and publications

The evaluation of the MPS RCT was published in November 2015
Police, Camera, Evidence: London's cluster randomised control trial of Body Worn Video    

The evaluation of the Essex RCT was published in October 2014
The Essex Body Worn Video trial  

Date due for completion

July 2019
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