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Panic alarms for domestic abuse victims

Testing the efficacy of new, innovative, audio-recording panic alarms within the household.

First published

Key details

Does it work?
Crime prevention
Criminal justice
Intelligence and investigation
Leadership, development and learning
Operational policing
Violence against women and girls
Violence (other)
Vulnerability and safeguarding

William Hodgkinson

Email address
Business and commerce
Criminal justice (includes prisons, probation services)
Stage of practice
The practice is implemented.
Start date
Completion date
Scale of initiative
Target group


The aim was to test the efficacy of an innovative audio panic alarm against the national standard alarm. This was tested with an evaluation framework of:

  • harm using the Cambridge Crime Harm Index (CCHI) (for domestic abuse and all crimes)
  • crime counts (for domestic abuse and all crimes)
  • calls for service
  • arrests
  • charges
  • police units deployed

It was assumed – based on the additional evidence corroborating that an offence had occurred and the capturing of the audio from within the address – that officers could arrest more and the Crown Prosecution Service (CPS) could charge more because the offence had been audibly captured.

Audio was played in interview with a number of very successful changes in the offender’s response after hearing themselves – particularly where there was an order prohibiting them from being present.

Intended outcome

The experiment assessed two types of outcomes, including prevention through the warning sticker and the ability to record crime. It also assessed evidence gathering to prosecute in otherwise difficult cases.

The measurable outcomes of the experiment were:

  • harm (for domestic abuse and all crimes)
  • crime counts (for domestic abuse and all crimes)
  • calls for service
  • arrests
  • charges
  • police units deployed

Data was captured from the call management system (CMS) and the crime reporting investigation system (CRIS). Outcomes are based on quantitative data sets.


New audio recording alarms were used and were tested against standard alarms. This project is also known as (Operation Protect). Panic alarms are procured under a national framework and available for all 43 force areas.

This new alarm is an innovative audio panic alarm that contains three vital pieces of additional functionality. These are:

  1. pre-activation audio recording of five minutes
  2. post-activation audio recording and monitoring up until police arrival (both of the audio clips are available for immediate review by responding officers)
  3. visual deterrent sticker placed on points of entry to the premises

This is tested by way of a randomised controlled trial across high-risk domestic abuse victims in London during COVID-19. The results indicate that both alarms are effective in reducing harm and repeat victimisation, but that the audio alarm achieves higher levels of arrest and charge.

To have the audio alarms the force needs a budget and to have signed up to the national procurement agreement.

The identification of suitable cases begins when an officer detects a high-risk domestic abuse victim who they believe would benefit from a panic alarm. When it was determined that an alarm would mitigate or reduce the threat, the officer contacted the victim to ascertain whether they would agree to an alarm being installed. Upon agreement, the officer applied to National Monitoring for an alarm for the victim.

Activation of the new alarm system (by pressing a handheld fob with two buttons) generated the same immediate dispatch of a police unit to the victim’s abode as the standard alarm. However, for the audio alarm, the call type detailed on the message was ‘audible panic alarm activation’ as opposed to ‘panic alarm’.

Once either alarm was activated, operatives in a control room received an alert with pre-recorded details of the location, victim, and case type. A computer-aided dispatch (CAD) reference was then generated.

The CAD was passed to a dispatcher who would communicate the need for an immediate response to the pre-assigned location due to a high-risk domestic abuse alarm activation.

A police unit was then dispatched to the location on an immediate grade call and the response officers were directed to turn on their body-worn video (BWV) cameras.

The process of dispatching officers to the victim was similar for both alarm groups. However, officers responding to addresses which had the new audio alarm system were also informed that an audio recording would be available and that they were required to review this at the scene.


A randomised controlled trial evaluation was conducted with the University of Cambridge.

The evaluation used a pre-test-post-test, control group design. Here, 300 eligible high-risk domestic abuse victims in London were randomly allocated to either a:

  • standard panic alarm system
  • panic alarm system with audio-recording capabilities and a red warning sticker on a durable, A6-size sign, displayed at eye level at the entrance to the premises

After receiving an alarm request, cases were randomised by National Monitoring to receive either a national standard alarm (model RDA2) or an audio-recording alarm with a visual warning sticker (model RDA3). Half received an RDA2 alarm and half received an RDA3 alarm.

Following this, the RDA2 or an RDA3 was installed by an engineer within 24 hours of random allocation.

Those who received an RDA3 also received an RDA2 as a backup in the event that the RDA3 failed to operate. The engineer checked alarm efficacy at the time of fitting and the alarms were monitored throughout. If an alarm was unplugged, National Monitoring were alerted.

Measures of harm were identified as calls for service, crimes, harm (measured by the CCHI), charges and alarm activations.

The CRIS and MPS’s CMS were used as the data-recording systems.

The population area selected had a very diverse population. Where there was a language barrier, language line and translators were used.

Overall impact

The overall impact was greater police action and criminal justice outcomes against domestic abuse perpetrators for high-risk victims.

Results from the evaluation showed the following.

  1. Use of a panic alarm as part of a policing response to high-risk domestic abuse achieves large reductions in harm and repeat victimisation. There is no difference between alarms, which supports that the warning sign had the same efficacy as no sign.
  2. Use of an audio panic alarm also increases police arrest and subsequent charging levels and rates.


The testing of this initiative, using a randomised control trial, took place during a global pandemic.

Barriers during the pandemic included restrictions in the movements of the public.

There was also an issue with the stickers being removed and therefore not being visible.

Challenges included:

  • victims refusing to accept the audio alarm
  • audio alarm evidence showing that an offence had been committed even where officers did not record an offence through their initial attendance
  • the requirement for re-attendance in some cases where officers had not listened to the audio recording at the scene


The copyright in this shared practice example is not owned or managed by the College of Policing and is therefore not available for re-use under the terms of the Non-Commercial College Licence. You will need to seek permission from the copyright owner to reproduce their works.

Legal Disclaimer

Disclaimer: The views, information or opinions expressed in this shared practice example are the author's own and do not necessarily reflect the official policy or views of the College of Policing or the organisations involved.

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