Unmanned aircraft have become the supply chain of choice for organised crime groups moving contraband into prisons. The UK Ministry of Justice publishes the numbers, and every line of the trend points the same way. If you are responsible for a custodial estate, the question is no longer whether drones will cross your perimeter, but whether you will know when they do.
The threat, measured
- 1,712 drone incidents at prisons in England and Wales between April 2024 and March 2025, a 43% increase on the previous twelve months. (Ministry of Justice, published 31 July 2025)
- Reported incursions have risen roughly tenfold since 2020, with 1,296 incidents in the ten months to October 2024 alone. (The Guardian, 1 January 2025)
- The MoJ committed an additional £900,000 to counter-drone work in 2025, on top of £40 million of annual security spending that already covers netting and reinforced windows. (GOV.UK)
Three cases that show the pattern
HMP Long Lartin, July 2025
West Mercia Police arrested four people after repeated drone flights over the high-security prison. The site is one of the most secure in the estate, and the flights happened anyway. Arrests came after the fact, from police work, not from an interdiction in the air. Detection plus evidence is what turned sightings into a prosecution case.
HMP Manchester and HMP Wandsworth
Joint counter-drone operations at these two sites led to nine arrests. At Wandsworth, officers recovered a drone kit valued at £6,000 with a 40-minute flight time and the capacity to carry four separate loads in one sortie. That is industrial logistics in miniature: one launch, multiple cell deliveries, back before staff are even alerted.
The arithmetic gap
Put the numbers side by side: over 1,700 sightings a year, a handful of arrests, and most flights logged only when an officer happens to look up. MoJ figures and reporting from Sky News and Channel 4 describe specialised gangs running scheduled routes, outpacing manual observation. The gap between sightings and interdictions is, in practical terms, the detection gap.
What detection has to do in a custodial setting
- Assume the aircraft will not identify itself. Smuggler drones do not broadcast Remote ID. A system built only on Remote ID reception will miss the flights that matter most, so RF-spectrum detection that finds the control and video links is the baseline.
- Work at night, at low altitude, at speed. Most contraband runs are short, dark and fast. Optical-only approaches degrade exactly when the threat peaks.
- Log the flight path and launch point. Evidence that stands up in proceedings is what converts a sighting into an arrest. Timestamped bearings and launch-point estimation are the deliverables that police partners actually use.
- Cover the whole approach, not one wall. The Wandsworth kit carried four loads per sortie. Flight profiles vary: high and fast, or low and slow along sight lines. Sensor siting matters more than sensor count.
How Ridfinder evaluates systems for prisons
Ridfinder is an independent advisory. We do not sell detection hardware, which means our specification reviews are driven by your threat picture rather than a product catalogue. For custodial sites we score candidate systems on four evidence-backed dimensions: detection layer coverage (Remote ID plus RF spectrum, radar where the site justifies it), launch-point accuracy, alert latency from first RF emission, and export-ready evidence logging.
For the underlying technology trade-offs, see our explainers on RF-spectrum detection and RID receivers, or how the layers compare in RID receiver vs RF detector vs radar. Standards context is in our Remote ID standards overview.
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