Sorry, you need to enable JavaScript to visit this website.

GPS knife crime tagging

Evaluating a pilot practice that uses GPS to reduce the likelihood of offenders committing further crimes, especially those involving weapons.

Key details

Lead institution
Principal researcher(s)
Tim Read
Police region
Level of research
Professional/work based
Project start date
Date due for completion

Research context

In 2017, the London Mayor’s Office for Policing And Crime (MOPAC) published the London Knife Crime Strategy.

Set against the backdrop of increases observed within Knife crime (both Nationally and London), the strategy took a public health approach to tackling knife crime and included a commitment to pilot the use of GPS tagging with knife crime offenders.

The overall aim of the pilot is to test GPS as a tool for reducing the likelihood of offenders committing further offences, especially weapon-related offences.

Specifically, this includes the use of GPS location data to:

  • improve the management of the risk posed to known adults, children and the public

  • improve the enforcement of licence conditions and increase deterrence

  • challenge the offenders’ thinking and lifestyle and improve rehabilitation

  • enable the Metropolitan Police Service (MPS) to map individual cohort crimes effectively to support crime detection

Research methodology


Performance data was gathered from a range of sources, mainly by the tagging provider Buddi and MOPAC delivery staff. This data included information about the tag wearers and the types of orders they were on, and their compliance with the tag.

In addition, data was provided by the MPS about the crime mapping element of the pilot (that is, numbers of crimes up-loaded, numbers of matches, and subsequent actions taken by the police).

Tag wearer survey

Tag wearers are asked to complete a short survey at the point the tag is fitted and again when removed.

The survey was designed by E&I and consists of three topics, which are:

  • the surveys aim to collect the wearers’ anticipated and actual perception of the impact of wearing the tag on their behaviour
  • their relations with friends and family
  • their lifestyle

At the time the interim report was produced (February 2020) data were available from 50 individuals where a tag had been fitted, but only five cases where the tag had been removed, the difference in the numbers being due to many tags still being active.

Because of the small number of removal cases, these data have not been analysed for this report but will be included in the final evaluation report as numbers increase. Surveys are administered by the tag fitter (staff members from Buddi).

Interviews with offender managers and tag wearers

By February 2020 semi-structured interviews had been undertaken with 12 OMs who had supervised those on the GPS knife crime tags. Those interviewed were asked about details of the specific case they had supervised, how they had used data from the tag in supervision, and for their views of the GPS tag in general.

In addition, semi-structured interviews were completed with a small number of service users (three individuals) who had been tagged. The interview asked about their experiences wearing the tag, their understanding of why they had been tagged, and their views of the tag overall.

Interviews with OMs and service users have continued since the publication of the interim report and will be reported in the final process evaluation report (due at the end of 2021). Interviews with MPS staff about the Crime Mapping element of the pilot have also been undertaken and the results will also appear in this report.

Impact analysis (looking at offending on and off tag) comparing the treatment group with a control group will also be undertaken and reported on at the end of 2022.

Was this page useful?

Do not provide personal information such as your name or email address in the feedback form. Read our privacy policy for more information on how we use this data

What is the reason for your answer?
I couldn't find what I was looking for
The information wasn't relevant to me
The information is too complicated