Although electromuscular incapacitation devices (Tasers or ‘stun guns’) have been in use for over a decade, concern about potential health effects has not been resolved. Moreover, public policy decisions have expanded the availability of Tasers and require wide consultation with the health sector as well as other stakeholders. In the past 5 years sales of Tasers have grown considerably, with numbers of US law enforcement agencies using the devices growing from 1700 in 2001 to 8700 in 2005 (US Department of Justice, personal communication). Jenkinson et al (Reference Jenkinson, Neeson and Bleetman2006) recently argued, as have the UK Police Federation, that Tasers should be issued to all front line British police, a move that would see a considerable proliferation of Tasers in the UK. A current trial in four districts may pave the way for Tasers to be used nationwide in New Zealand (New Zealand Police, 2006). These developments make it imperative that health professionals monitor the physical and mental health implications of Tasers, and ensure health considerations are part of the public policy debate on their deployment. In this paper we review the existing literature on the use of Tasers, and note that the psychological effects of Taser use have not been investigated.

The currently used model of Tasers, the X26, is a battery-operated unit resembling a hand gun that fires two barbed electrodes on copper wires of up to 35 feet, at 180ft/s (Taser International, 2005). The barbs embed themselves in the victim's skin or clothes and deliver up to 50 000 volts of electricity with 1.76 J of energy in rapid pulses over a period of 5 s, causing uncontrollable muscle contraction and overwhelming pain (Taser International, 2005). Repeated charges of electricity can be administered. Tasers are used for law enforcement in the USA, Canada, Australia and the UK, and were recently introduced for a 12-month trial in New Zealand. Despite reports of concerns about their potential health implications (Reference Bleetman, Steyn and LeeBleetman et al, 2004; Reference RappertRappert, 2004a ; Reference Bozeman and WinslowBozeman & Winslow, 2005) there is little published scientific research into their effects on physical or mental health. The small body of research into Taser safety suggests that the devices are safe in healthy individuals with no predisposing risks, but is cautious about their use in some atrisk groups. Because mental health consumers may fall into one or more risk categories, any use of Tasers with that group requires a high level of vigilance.

Method

We searched the online databases Web of Science, Medline, CINAHL, PsychINFO and EMBASE. Search terms included Taser, stun gun, electromuscular incapacitation device, neuromuscular incapacitation device, non-lethal weapons AND conducted electrical weapon. In addition, we searched reference lists and relevant websites. The final source of reports was the publications list on the site of Taser International (http://www2.taser.com).

Results

The medical literature contains just one published review (Reference Jenkinson, Neeson and BleetmanJenkinson et al, 2006). Other peer-reviewed literature includes case reports, discussion papers and experimental studies (Reference Bleetman, Steyn and LeeBleetman et al, 2004; Reference RappertRappert, 2004a ; Reference Bozeman and WinslowBozeman & Winslow, 2005; Reference Dobrowalski and MooreDobrowalski & Moore, 2005; Reference Ng and ChehadeNg & Chehade, 2005; Reference Chen, Richard and MurthyChen et al, 2006). We located numerous unpublished police reports and reviews as well as a number of discussion documents. In this report we refer to peer-reviewed publications and those unpublished documents that contain data not found in the peer-reviewed literature.

Discussion

Tasers appear to be safe when used on healthy individuals (Reference Bleetman, Steyn and LeeBleetman et al, 2004; Reference Jenkinson, Neeson and BleetmanJenkinson et al, 2006). The rate of mortality and morbidity is low when the number of reported deaths and injuries is considered in relation to the widespread use of Tasers in the USA. However, as Tasers become more widely used health researchers need to monitor their possible health consequences, including effects on mental health (Reference McBride and TedderMcBride & Tedder, 2006). The question of the contribution of Tasers to unexplained deaths in custody remains unresolved. Inconsistencies and inadequacies in the documentation of Taser-related deaths and injuries mean that there is likely to be under-reporting of these events (Reference McBride and TedderMcBride & Tedder, 2006). Reports of cause of death are likely limited in the case of Tasers because attributions of cause of death are usually made on the basis of the final failure of vital organs, rather than on the basis of multiple contributing factors (Reference McBride and TedderMcBride & Tedder, 2006). The multiple factors operating in Taser-related deaths require closer analysis of the sort being undertaken by the National Institute of Justice in order to be more fully understood. In particular, the hypothesis that Tasers may contribute to an already high level of arousal of agitated individuals, and thus to their eventual death, needs to be researched.

We were surprised by the lack of literature on the implications of Taser use on individuals with mental illness, and the lack of attention to the mental health implications of Taser use on all populations. As Jenkinson et al (Reference Jenkinson, Neeson and Bleetman2006) assert, any use of force has the potential to cause injury. We would add that force is also a source of trauma for both police and for the victim. Tasers may be legal and even necessary from a law enforcement perspective, but as McBride & Tedder (Reference McBride and Tedder2006) noted, health researchers need to investigate their mental health consequences.

Making an informed decision about whether Tasers are appropriate for police use is a public policy decision (Reference RappertRappert, 2004a ), one factor in which is the health implications of their use. Also relevant are wider issues such as prevention of injury or harm to others and the image of the police. For instance, these issues may well be different if the proposed use is limited to an alternative to lethal force. This cost-benefit argument is different from that involved in issuing Tasers to previously unarmed police officers, where the Taser becomes an alternative to, for example, pepper spray, as recommended by Jenkinson et al (Reference Jenkinson, Neeson and Bleetman2006), or is simply used as a means of gaining compliance or deploying fewer police officers. Furthermore, as health professionals are required at times to provide care following the use of Tasers, it is imperative that clinical and ethical guidelines for health professionals are promulgated. This is particularly so when the police are involved in the processes of detaining a person with mental illness under civil commitment statutes. Use of Tasers is a public policy issue that demands the vigilance of health professionals and researchers (Reference RappertRappert, 2004b ).

Declaration of interest

None.