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TASER basics: What every judge and jury should know

Judges and juries still seem to have problems understanding how TASERs work and why officer use them. My experience is that some officers have difficulty clearly articulating the basics. So, I thought I would provide you with a document I have developed in recent years for use in my reports and in court.

As I learn new things, I update the document. Any feedback on improving it would be welcome!

TASER Basics
The TASER Electronic Control Weapon (ECW) has been used by law enforcement since the mid-1970’s to subdue a subject who is resisting or who is combative. Prior to 1999, a few hundred law enforcement agencies used various models of CEDs. Since 1999, when technological changes made TASER ECWs more effective, many thousands of law enforcement agencies have deployed CEDs for use by patrol, specialized units, jails, and prisons. The TASER M26™ CED was introduced in 1999; the TASER X26™ CED was introduced in 2003; the TASER X3 CED was introduced in 2009; the TASER X2 CED was introduced in 2011. The TASER X26 CED is the most often used model.

It must be noted that there are several generic terms interchangeably in use in the literature and in practice to describe such devices: Conducted Energy Devices (CED), Conducted Energy Weapons (CEW), Electronic Control Devices (ECD), Electronic Control Weapons (ECW).

The purpose of using a CED is to cause a subject to quickly stop resisting or fighting. TASER ECWs may be used in the “probe” mode (to cause temporary neuromuscular incapacitation, or NMI) or in the “drive-stun” mode (which is generally considered to be a pain-compliance technique that is a lesser quantum of force than deploying the probes). Numerous studies have reported that TASER ECW use results in fewer and less severe injuries to subjects and officers than many other use-of-force tools and tactics.

Studies have shown that more than 80 percent of law enforcement agencies that deploy CEDs consider them to be at the same force quantum level as pepper spray (a.k.a. “OC spray”). However, experience has shown that CEDs are generally more effective on subjects than pepper spray, and the effects of CEDs are of brief duration (a few seconds in most cases) while pepper spray effects generally do not dissipate for 45 minutes to an hour or more. For that reason, officers who have experienced the effects of both CEDs and pepper spray overwhelmingly would prefer to be exposed to a CED again rather than pepper sprayed if given the choice. Typically approximately 95 percent answer that way when groups of them are asked, based upon my personal experience of asking that question in the classes that I have taught across the country over many years.

The “probe” mode is the most effective way to use the TASER ECW. When used in the probe mode, the TASER ECW gives the officer the opportunity to maintain distance from an aggressive/threatening subject. When “activation” occurs, two tiny probes are launched and (ideally) attach to a person’s clothing or skin to complete the circuit back to the TASER ECW. The voltage helps the electricity pass through up to two cumulative inches of clothing. In probe mode, the TASER ECW is aimed by a LASER sight that gives the officer knowledge of where the top probe is likely to impact the suspect. (Some recent models feature LASER sights for both the top and bottom probe placement.) The greater the separation of the probes on the body, the better the results will be for the effectiveness of the TASER ECW.

A successful probe deployment results in the probes being spaced more than four inches apart while targeting major muscle groups, and preferably a foot or more apart.

The probes are less effective on fatty tissues than on major muscle groups. TASER ECW effectiveness generally does not depend upon the size, weight, intoxication level, or level of agitation of the subject. Effectiveness is generally dependent upon delivering the probes effectively (with sufficient spread between the two probes, which must remain attached to the subject).

When the officer deploys the TASER ECW in probe mode, and the two probes attach to the suspect’s clothing or skin, the device will send a pulsating electrical charge. When there is a successful probe deployment, the subject typically is disabled for the duration of the cycle. The high-voltage, low amperage electrical charge is designed to induce motor-nerve mediated involuntary muscle contractions (NMI) by sending impulses that override the signals of the sensory and motor nervous systems that are sent to and from the central nervous system (CNS). Should only one probe strike the suspect and the other probe fail to make contact, or if one probe attaches to clothing but is more than two inches away from the body, or if one or both probes lose contact with the subject for any reason, or if the probes are too close together on the body, the CED will typically not incapacitate the subject unless the officer is able to approach the subject and do a follow-up “drive-stun” on the subject, which will complete the circuit with the wire(s) that attached during the “probe” mode attempt.

The “drive-stun” mode is generally considered to be a “pain-compliance” technique, thus a lesser quantum of force than using the probes. Law enforcement uses a variety of pain-compliance techniques on resisting or assaulting subjects who might stop their resistance or attack if they feel pain. However, some subjects in combative situations apparently do not feel pain, so pain-compliance techniques may not work. Officers generally should not expect NMI to result from a drive-stun. The contact points on the TASER X26 ECW are only 1.6” apart, not enough to achieve the effects of a good probe spread. In addition, in a dynamic altercation it is very difficult for an officer to apply and maintain the application of a drive-stun to a person who is resisting or who is reacting to the pain-compliance technique. The drive-stun contact points typically touch the body for part of the time, but are out of contact with the body for part of the time during the dynamic struggle to subdue the subject.

The TASER ECW user may deliver different levels of force (“quantum of force”) by controlling the amount of time of the activation(s) of both the probe and drive-stun modes, and based upon what the officer reasonably perceives about the circumstances of the use. When the TASER X26 ECW is activated, the default cycle runs five seconds, then the power automatically shuts off, unless the officer holds the trigger back. The standard five-second cycle for probe application is what is usually taught in training. Ideally, back-up officers approach and attempt to handcuff/control the subject during the five-second exposure (known in this context as the “window of opportunity” and “cuffing under power”) while the suspect is temporarily incapacitated. However this cannot always be accomplished for a variety of reasons, and additional activations may be needed to control the suspect until handcuffing occurs.

Circumstances may dictate additional or prolonged activations if the subject is not responding to the effects of the TASER ECW. Officers are trained to assess the effectiveness of the device prior to pressing the trigger for a second or subsequent cycle, or holding the trigger back to extend the cycle; and to consider transitioning to another technique if the TASER ECW repeatedly proves ineffective. However, officers must be cognizant that if transitioning to another technique constitutes an escalation of force, then there is a greater likelihood that the subject, as well as officers, will be more seriously injured; thus the officer might continue to attempt to use the TASER to overcome the subject’s resistance or combative actions in order to reduce greater injury risks.

Officers can (and generally should) warn the subject of impending TASER ECW use in a variety of ways, used separately or in combination: verbal warning that it will be used, verbal warning that it will hurt, display of the device, turning on the LASER pointer, and activating the device with the cartridge removed (from the M26 and X26 models) in order to demonstrate the electrical arc and sound. In some cases, verbal and/or demonstrative warnings deter the subject from further resistance. In other cases, the dynamics of the situation do not allow time for a warning to be given (such as when the officer faces an immediate threat as opposed to an imminent threat); or the struggle is already in progress; or the subject’s demeanor, mental state, level of intoxication and/or agitation are such that giving a warning would not be comprehended by the subject.

A relatively “quiet” CED sound (whether using probes or drive-stun) indicates a good connection/contact and it is most likely functioning properly. If the CED sound is loud and can be easily heard, it indicates a poor contact with the suspect, and the CED is most likely having little or no effect on the suspect. When probes are deployed but one hears the CED loudly making its “clicking” noise, it indicates the CED wires attached to the probes may have been broken or damaged; or the probes or contact points of the CED were not at various times making effective contact with the subject.

There is a distinct difference between “activation” and “application” when a CED is used. For accountability, the X26 and M26 internal computer records the time of occurrence and the duration of each “activation” and “cycle,” and this and other data are available via the “download printout.”

To orient the reader to these terms, here are brief definitions:

Activation: the trigger is pulled, and a clicking sound is heard, whether or not the device is connected to a person. If there is an “application,” the clicking sound tends to be muffled. If there is no “application,” the clicking sound tends to be loud.

Application: an “activation” occurs, and electricity flows to a person, whether by effective contact with the two tiny probes that launch from the device (probe deployment) or by touching the front of the device to a person (drive-stun), or by a combination of the two.

Cycle: when “activation” occurs, the device automatically runs for five seconds, unless the operator turns the device off prematurely, or (for some models, including the X26) holds the trigger back to lengthen the cycle.

Download Printout: Using a computer loaded with TASER X26 ECW download software, one can produce a “download printout” to observe data for each “activation” including the time of occurrence, the duration of each “cycle” in seconds, the internal temperature of the device, and the remaining percentage of battery charge. The recorded activation time is the end of the cycle. One-tenth of a second of activation will record as a full second. For example, an activation lasting from 3.1 seconds up to 4.0 seconds, will record on the printout as “4 seconds.” For the M26 and X26 models, the computer technology does not detect whether there was an “application,” or merely an “activation.” However, forensic analysis of the probes and wires can often determine whether there was an application and the approximate duration of the application. TASER CED clocks are not usually found to be synchronized with each other, nor do they reflect “real time” unless synchronized with a real-time source; this is known as “clock drift.”

Greg Meyer, a retired Captain from the Los Angeles Police Academy, served for 30 years, including eight years as a commanding officer. Greg is a member of the National Advisory Board of the Force Science Research Center, a member of the Police Executive Research Forum (PERF) and the International Association of Chiefs of Police (IACP).