An analysis of officer-reported TASER X2™ probe discharge effectiveness in the United Kingdom

Conducted energy devices (CEDs) are designed to immobilise aggressive individuals through the application of an electrical discharge administered via probes fired at the subject. Although the discharge is intended to disrupt voluntary movement, CEDs have their limitations and several factors are qualitatively understood to adversely influence CED effectiveness. The introduction of the twin-cartridge TASER X2™ into UK policing in 2017 provided a unique opportunity to undertake a quantitative assessment of the factors modulating probe discharge effectiveness based on data reported by police officers firing the device operationally. The overall operational subdual effectiveness of the TASER X2™ was 68.5%. However, several factors were identified that could alter the likelihood of achieving subdual of the subject. The officer-reported data show that probe discharge was highly effective at subduing subjects when both probes had penetrated the skin, least effective when both probes were in clothing and confirmed the reduced effectiveness of narrow probe spreads. The most commonly cited reasons why probe discharge failed to subdue the subject were thick or loose clothing, probe misses and narrow probe spread. These findings, which are likely to generalise to other types of CED, may be used to inform tactics and training to optimise the likelihood of achieving incapacitation when probes are deployed, with benefits for the safety of both the police and the public. The findings may also assist investigations requiring the reconstruction of incidents in which probe discharge has been deployed.