SelectaDNA Defence Spray Helps Police Identify Illegal Off-Road Riders in Hertfordshire

In May 2026, officers from Hertfordshire Constabulary's Baldock and Letchworth Neighbourhood Policing Team used SelectaDNA Defence Spray to mark two riders operating off-road motorcycles illegally on public land, which ultimately led to both individuals turning themselves in. 

The operation demonstrates how SelectaDNA’s forensic marking technology supports frontline policing of anti-social vehicle use - giving officers a means of identifying individuals even after they flee the scene. 

Find out more about SelectaDNA Defence Sprays

The Operation 

Officers observed two petrol-powered off-road motorcycles being ridden in an anti-social manner on Grange Recreation Ground in Letchworth on 14 May 2026. When the riders became aware of the police presence, they fled onto the Greenway. Anticipating their route, officers repositioned to key access points.  

As the riders attempted to pass, officers deployed SelectaDNA Defence Spray, marking both individuals with our identifiable and traceable synthetic DNA solution. It was soon after that the riders abandoned their motorcycles and decided to flee on foot. 

After forensic tagging had been deployed, both riders contacted their parents after becoming concerned about the substance that had been sprayed on them. This ultimately led them to voluntarily return to the scene and handed themselves in. 

When examined under ultraviolet light, the SelectaDNA solution was clearly visible on both riders. Each admitted to riding illegally on the Greenway, they were reported for the relevant offences, and both motorcycles were seized for being ridden without insurance. 

PC Callum Ellis of Hertfordshire Constabulary said: "This result demonstrates our proactive approach to tackling illegal off-road biking and the effectiveness of forensic marking technology. We continue to act on information provided by the public and remain committed to addressing anti-social vehicle use in our communities." 

How SelectaDNA Defence Spray Works 

SelectaDNA Defence Sprays deploy a synthetic DNA solution that is invisible to the naked eye but fluoresces under ultraviolet light. Each batch carries a unique DNA code, meaning any person or item tagged can be forensically linked to a specific time and location. 

The solution is harmless and long-lasting, transferring easily to skin and clothing on contact and remains detectable for an extended period. Officers can use a handheld UV torch to confirm contact at the scene, with full laboratory analysis available to support evidential proceedings. 

Why Forensic Marking Supports Anti-Social Vehicle Operations 

Illegal off-road motorcycle use presents a persistent challenge for neighbourhood policing teams. Riders who flee on foot typically cannot be pursued safely. However, forensic marking addresses this gap: once tagged, an individual carries traceable evidence regardless of whether they are detained at the scene. 

In this case, the knowledge that the riders had been marked with an identifiable substance prompted both of them to return voluntarily. This outcome illustrates how the psychological deterrent effect of forensic marking can generate results without requiring physical apprehension. 

This deployment was the first under Operation AAORM (Action Against Off-Road Motorcycles) in North Hertfordshire to result in a direct enforcement outcome. Following its success, SelectaDNA products continue to be deployed across the area as part of wider community crime reduction initiatives.