Weapons Law Encyclopedia

Projectile Electric-Shock Weapons (Tasers)

Electricity was being used as a weapon long before the advent of projectile electric-shock devices. The invention of the electric chair, first used for executions in 1890,Darius Rejali, Torture and Democracy, Princetown Press, 2007, p. 24. was one of the earliest such uses of electricity – and by definition was for lethal not ‘less-lethal’ ends. Since then, existing electrical devices have been adapted, and new electrical weapons developed, with a view to producing outcomes short of death.

One of the earliest examples of adaptation was the ‘dual purpose magneto’ — a generator that produces a ‘high voltage spark’ and which was often to be found in portable field telephones — which was used by French colonial troops in the 1930s in Vietnam for ‘interrogation’ and ‘torture’;Ibid., pp. 145–6. ‘widely used’ by the US Military and the Army of the Republic of Vietnam during the Vietnam War Michael Peterson, ‘Designed for Disappearance: The U.S. military field telephone TA-312/PT and the performance principle of torture’, Performance Research: A Journal of the Performing Arts, Vol. 12, No. 4 (2010), p. 143. and whose use ‘spread to Asia, Africa, South America, North America and the Middle East’.Rejali, Torture and Democracy, p. 167. Another example was the use of the electric cattle prod, or ‘picana electrica’, most commonly used in Argentina.

Electric-shock weapons specifically intended for less-lethal use on human beings were also developed. A patent for an electrified police baton was introduced in 1964 by the main manufacturer of electric cattle prods,Rejali, Torture and Democracy, p. 228. and today a plethora of similar devices exist, including stun batons and stun ‘guns’. However, these ‘contact’ electric-shock weapons differ markedly from their projectile electric-shock counterparts. Unlike the latter, the shock cannot be delivered from a distance as the weapon must be pressed directly against an individual to produce an electric shock, and the intended effect of this shock is localized pain, as opposed to neuromuscular incapacitation (see the Impact section for more details).

Work soon started on projectile electric-shock weapons which would overcome these issues, with a series of patents for Taser, and the circuitry underpinning them, filed in the early 1970s by the inventor John Cover.Rejali, Torture and Democracy, p. 229. According to the original patent, the product envisaged was one which would deliver an ‘electric charge sufficient to immobilize’ via ‘a harmless projectile’ — variously conceived — that is ‘connected by means of a relatively fine, conductive wire.’Seantal Anais, ‘Conducted Energy Weapons’ in S. Dam and J. Hall (eds.), Inside and Outside of the Law: Perspectives on Evil, Law and the State, Interdisciplinary Press, 2008, p. 53.

Yet initial resistance from various groups (including the military, police, and airlines); ongoing technical issues; and changes to the legal classification of the product meant that the weapon’s use was not initially widespread. Eventually an earlier version of the Taser models in use today — with more power than the first patented creations, dart-firing probes, and a trigger which stayed depressed once the officer’s thumb was taken off — was taken up by the Los Angeles Police in the 1980s, and then more broadly.Rejali, Torture and Democracy, p.229. Additional Taser models — the M26, X26 and the ‘next generation’ of products: the X2, X3, and X26P — all of which work on the dart-firing principle, were refined and produced, and competitors, both in the USA and abroad, also started producing their own versions of projectile electric-shock technology, to rival Taser designs.

Today, use of projectile electric-shock weapons, particularly of the Taser models, is widespread. Statistics from Taser International/Axon state that, as of June 2012, Taser brand weapons had been sold to 16,880 law enforcement and military agencies worldwide, and were available in 107 countries. Axon Media Press Kit.

Last updated on: 04 August 2017

Projectile electric-shock weapons come in a range of forms and are produced by a range of different companies. Unlike contact electric-shock weapons, which are only capable of producing pain, projectile electric-shock weapons aim to cause neuromuscular incapacitation by producing an electrical pulse which interferes with communication between the brain and the muscles. See also: S. Upson, 'How a Taser Works', IEEE Spectrum, 30 November 2007.  When successful this results in involuntary muscle contractions and impaired motor skills — as well as intense pain — for at least as long as the duration of the shock. These systems are thus meant to be more effective than those that rely on pain compliance alone. Neuromuscular incapacitation is believed to result from a combination of several factors, including the pulse used, the frequency of the pulses, and the spacing of the probes.Police Scientific Development Branch, PSDB Evaluation of Taser Devices, 2002, p. 4. (For more on the intended and unintended effects of these devices, see the Impact page).

The most commonly used design is that of an electric-shock delivered via two insulated, tethered darts with a range that usually varies from 4.5 to 10 metres, depending on the cartridge selected. The most widely known manufacturer of such devices is Taser International (today called Axon), which has produced a range of probe-firing weapons. These include the M26, X26, and the ‘next generation’ of products, the X2, X3, and X26P which vary in terms of the electric-charge produced, the additional accountability features available with the product, and the size, shape, and colour of the unit.

Similar designs have been produced and/or marketed by rival companies in the USA and by companies in the Russian Federation, e.g. Mart. Brazil, Taiwan, and China. Several of these alternative designs are multi-purpose, capable of firing not only wired electric-shock darts, but kinetic impact and chemical irritant projectiles as well. While projectile electric-shock darts or probes remain by far the most common system, a range of other projectile electric-shock weapons—both wireless and wired—have been developed and marketed. These include:

  • A 40mm long-range wireless projectile, the ‘Human Electro-Muscular Incapacitation Device’, designed to be fired from the M203 or the M320 grenade launchers, Human Electro-Muscular Incapacitation Device FAQ, U.S. Department of Defence. currently being developed by Taser International under a $2.5 million contract from the US Department of Defence. D. Hambling, 'Long-range Taser raises fears of shock and injury’, New Scientist, 28 October 2009.
  • A smaller wireless projectile, the Extended Range Electronic Projectile (XREP) designed by Taser International to be fired from 12-gauge shotguns and to incapacitate at up to 30 metres without wires attached. Independent tests, however, found the weapon to be inaccurate at 20 metres and to vary considerably in the length of electric shock delivered: while it was intended to deliver an electric shock for 20 seconds, some rounds were ‘electrically dead’ and others delivered an electric shock for ‘more than 5 minutes after being activated’. Further independent testing confirmed that the projectile was highly inaccurate, unable to hit the target at a range of 12 metres. In 2012, Taser International announced it was discontinuing sales of the XREP, citing languishing sales D. Sherman and C. Bir, ‘A test methodology for the complete characterisation of the Taser XREP Munition’, Paper presented to the 2009 Ettlingen Symposium on Less Lethal Weapons, 2009; and S. Kunz, M. Graw, O. Peschel, and N. Grove, ‘Long-distance Conducted Electrical Weapon XREP function and ballistic features’, Paper presented at the 6th European Symposium on Non-Lethal Weapons, 16–18 May 2011, Ettlingen, Germany; Taser International (2012), Letter to Taser Distributors, Omega Research Foundation archive.
  • The ‘Shock Wave’ is a wired, area denial system produced by Taser International and made up of one or more individual units. Each unit is capable of launching six Taser cartridges of similar power to the X26. S.M. Bruner, 'Crowd Control: The Taser Shockwave', PoliceOne, 19 March 2010.
  • Occasionally electric-shock weapons are developed which use projectiles other than darts. A patent filed by the inventor of Taser, Jack Cover, in 1972 envisaged a weapon that could fire ‘a net ... or a plurality of pellets connected by a mesh or net’. United States Patent US 3803463 A, Weapon for Immobilization and Capture, pp 1, 6.  Taser does not currently produce such a product. In 2008, however, a Chinese company had marketed a weapon capable of firing an electrified net. As of writing, this product seems no longer to be available.

Last updated on: 04 August 2017

Projectile electric-shock weapons aim to cause neuromuscular incapacitation by producing an electrical pulse that interferes with communication between the brain and the muscles. When successful, this results in involuntary muscle contractions and impaired motor skills - as well as intense pain - for at least as long as the duration of the shock. See also: S. Upson, 'How a Taser Works', IEEE Spectrum, 30 November 2007. However, debate about the exact impact of projectile electric-shock weapons is fierce and wide-ranging. In this section, the focus is on the impact of Taser products, as these are the models most widely deployed and most commonly studied.

Efficacy rates for Taser vary both between models and between different assessments of the same model. Efficacy rates for the Taser X26, one of the most widely used models, vary from 95% As claimed by the manufacturer; A. Berenson, 'Citing Some Flaws, Taser to Increase Stun Gun's Power', The New York Times, 21 January 2005. to ‘74% to 52% depending on distance to the target’ for the X26 and M26. The Joint Non-Lethal Weapons Human Effects Center of Excellence, Human Effectiveness and Risk Characterization of the Electromuscular Incapacitation Device: A Limited Analysis of the TASER, 2005, p. ii. Little information is available for products other than the Taser brand. However, Amnesty International has documented 334 deaths subsequent to Taser use in the USA between 2001 and 2008 .Amnesty International, Less than lethal? The use of stun weapons in US Law Enforcement, 2008. Other tallies claim the number of deaths worldwide were as high as 794 (as of 2011). Truth... Not Tasers, Blog. Projectile electric-shock weapons have also been associated with a range of health concerns, both resulting from the weapon itself and the external circumstances surrounding its use.

Circumstances surrounding its use

The 2013 Taser product warning notes that ‘the loss of control resulting from a CEW exposure may result in injuries due to a fall or other uncontrolled movement.’ It goes on to caution against use on ‘a person who is on an elevated or unstable surface ... could fall and suffer impact injury to the head or other area; could fall on a sharp object or surface … is less able to catch or protect self in a fall; ... is running, in motion, or moving under momentum ... (including) riding any mode of transportation; ... or is located in water, mud, or marsh environment if the ability to move is restricted.’ Taser International Product Warning.

A paper in the journal The America Surgeon also highlighted the ‘potential danger of significant head injuries as a result of loss of neuromuscular control’, risks that are underscored by American jurisprudence, including Snauer v. City of Springfield, where the Court determined that the use by a Springfield police officer of a Taser on a fleeing suspect while the latter was at the top of a six- to seven-foot-high fence was objectively unreasonable. When the suspect was hit by the probes, he became temporarily paralysed, plunged head-first to the other side unable to break his fall, and sustained multiple spinal fractures.B. Mangus, L. Shen, S. Helmer, ? Maher, , Smith, J ‘Taser and Taser Associated Injuries: A Case Series’, The American Surgeon, Vol. 74 (2008), p. 9; and Law International Inc., ‘Summary of Snauer v. City of Springfield’, Electronic Control Devices: Legal Resources website.

Another significant cause of injury can occur when Taser is used around flammable substances, which include certain chemical irritant sprays used by the police. Braidwood Commission on Conducted Energy Weapon Use, Part 9: Medical Risks,  2008, p. 266.

The impact of the weapon itself

Perhaps more contentious is the direct impact of the weapon itself, not least as there remain large gaps in our collective knowledge. For example, studies on repeated and/or continuous exposure to Taser are lacking. Indeed, Taser International has noted that ‘most human CEW lab testing has not exceeded 15 seconds of CEW application, and none has exceeded 45 seconds’,Taser International Product Warnings, op. cit. and a study in 2013 was ‘the first that has attempted to isolate specific bioeffects associated with continuous long duration exposure.’D. Jenkins, B. Murray, M. Kennett, L. Hughes, and J. Werner, ‘The Effects of Continuous Application of the TASER X26 Waveform on Sus scrofa’, Journal of Forensic Sciences, Vol. 58, No. 3 (2013), p. 684.

Of the studies that have been conducted, relatively few have been conducted on humans, and those that have, often use police officers as their subjects. The literature that does exist has highlighted potential areas for concern, including the following:

  • Cardiac complications. The medical literature is predominantly concerned with assessing the risk that Taser deployment may result in death, predominantly through ventricular fibrillation and other effects on the heart. These studies have generally found the use of Taser to be relatively safe (for a useful overview, see the Braidwood Inquiry, op. cit.). However, a study in the American Heart Journal found that authors affiliated to Taser were 18 times more likely to find that the Taser’s impact on the heart is ‘likely safe’ than those without such affiliation.P. Azadani, Z. Tseng, S. Ermakov, G. Marcus, and B. Lee, ‘Funding source and author affiliation in TASER research are strongly associated with a conclusion of device safety’, American Heart Journal, September 2011, p. 533. Some studies have found that the use of such weapons ‘can cause cardiac electrical capture and provoke cardiac arrest’.D. Zipes, ‘Sudden Cardiac Arrest and Death Associated with Application of Shocks from a TASER Electronic Control Device’, American Heart Journal, 2012. Particular sub-groups can be particularly vulnerable. For example, Multerer et al. highlighted the ‘arrhythmogenic potential of a Taser in otherwise healthy young individuals’. S. Multerer, J. Berkenbosch, B. Das, and C. Johnsrude, ‘Atrial Fibrillation After Taser Exposure in a Previously Healthy Adolescent’, Pediatric Emergency Care, Vol. 25, No. 12 (2013), pp. 851–3.
  • The impact of the weapon on respiration. The medical evidence is somewhat contradictory, with one study on pigs showing interference with breathing and one study on humans showing no such interference. However, reports by the US Department of Defence and the Canadian Police Research Centre have highlighted increased risks depending on the placement of the darts and the duration of the shock. Braidwood Commission on Conducted Energy Weapon Use, 2008, p. 243.
  • The risk of a ‘brain-specific complication’ based on a case report of a ‘previously well’ police officer who was accidentally hit by Taser and developed a ‘generalized tonic-clonic seizure’. Although he had no further seizures, ‘a year later’ his ‘symptoms of anxiety, difficulties concentrating, irritability, nonspecific dizziness and persistent headaches ... (had) not completely resolved.’ E.T. Bui, M. Sourkes, and R. Wennberg, ‘Generalized Tonic-Clonic Seizure after a Taser Shot to the Head’, Canadian Medical Association Journal, 17 March 2008.
  • The risk of penetration by the probes. Literature has highlighted cases where Taser darts have penetrated the eye. S. L. Chen, C. Richard, R. Murthy, and A. Lauer, ‘Perforating ocular injury by Taser, Clinical & Experimental Ophthalmology’, Vol. 34, No. 4 (2006) and the head (Mangus et al., op. cit.

Last updated on: 04 August 2017