A decision by the SA Police force to widen the use of Taser weapons, has prompted my re-examination of doubts about their safety.
The changes proposed include:
- Ability to use them against unarmed persons
- One officer in a patrol crew to be able wear a Taser on his/or her belt.
- 2600 police have been trained in the selective use of Tasers, and it is envisaged that in time all officers will be so equipped as a deterrent, and for use in situations of unexpected danger.
Two posts in my blog Technically Speaking looked at the safety of Taser Guns, in the light of the death of 21 year-old Brazilian student Roberto Curti March 18, 2012.
This post seeks to appraise the advantages and risks of their use as objectively as possible.
Background information about Tasers
Invented in 1969 by John H Cover, a scientist at NASA, and titled TASER, an acronym for “Thomas A Swift’s Electric Rifle”, after a book he had read in his youth, written by Victor Appleton.
Taser International commenced manufacture of a range of electro-shock weapons in the USA in 1999. They have been marketed globally mostly to law-enforcement agencies.
The Taser guns now employed by the police fire two probes which deliver high voltage (50,000V) but low current, electric shocks, calibrated to last only 5 seconds. They cause agonizing stimulation of nerves, and violent muscular contraction, causing the patient to fall uncontrollably. Ordinarily the victim recovers quickly once the shocks have terminated.
Mode of Action
No matter how carefully they may be used, they are not without significant risk. The symptoms vary with the site of the tasering, and the risk of untoward side effects is increased in the presence of pre-existing heart disease, mental illness, and drug use.
The high voltage electric current (50,000 volts) causes immediate agonizing muscular spasm, and loss of muscular control, depending on the site.
- Subjects are likely to fall helplessly, and in doing so may injure themselves, with serious possible consequences.
- When the chest is tasered, the muscles of respiration will be affected, and breathing temporarily halted.
- The heart is a muscular structure, and electrical stimulation of the heart could cause a cardiac arrest, or send the heart into a fatal arrhythmia.
- Stimulation in the vicinity of the head is likely to provoke a brain seizure (epileptic like fit)
Immediate agonizing pain for the duration of the stimulation.
It increases agitation and restlessness, and makes the individual even more difficult to control.
It may lead onto a life-endangering state characterised by delirium, hyperactivity, with almost super-human strength to resist restraint, a dangerously rapid pulse, raised body temperature, and increased ventilation.
Increasingly the descriptive term “Excited Delirium” is being used for the cause of death in victims who die following Taser treatment.
A preferable diagnosis for this dangerous medical condition was suggested by an Expert Panel reviewing Taser deaths in the Canadian Province of Nova Scotia. It is “Autonomic Hyper-arousal State” (AHS).
A Part II post will examine the pros and cons of the use of Taser guns.