I am an emergency medicine physician and a law enforcement officer. These two professions leave no doubt that my roles on this planet are to serve and observe.

While serving others, I have had the privilege of observing many things about people in crisis and society in general and if I had to distill my observations down to two main points, they would be:

• People often need to be saved from themselves.

• Miscommunication and misunderstanding is at the root of every crisis.

I cannot change human behavior so point one is really more like a permanent law of society, and I view it as favorable to my job security. However, point two can and should be corrected when it occurs.

Over the past five years, I have had the privilege of working very closely with all of the technology that TASER International has brought to the field of law enforcement. I have used some of it in training and some of it while on the job. I have played with all of it in the research lab, and I have been called upon on many occasions to talk and teach about what I know and what I have learned regarding this technology. It has been interesting to see how the evolution of this technology has changed the way that law enforcement does its job. The ability for these devices to gain compliance when used properly while reducing officer and suspect injuries is remarkable.

As part of the evolution of TASER technology and tactics, a recent training bulletin was issued by TASER International to update users about what is believed to be the current best practice. This bulletin has been interpreted differently by agencies and individuals. Some of the misinterpretations span the spectrum from "No changes, business as usual" to "We are totally banning these devices from use at our agency." As in almost every situation that has this much polarity, the truth lies somewhere in the middle.

I have had many cops, chiefs, docs, nurses, attorneys, and reporters contact me to ask for my opinions of TASER's new training advisory. The one thing that is clear from their questions and comments is that the bulletin has many statements and details that educated people did not fully understand and that the media reported incorrectly.

As I stated above, a crisis that stems from miscommunication or misunderstanding deserves to be corrected when it occurs. This led me to make a list of items from this training bulletin that need more detailed explanation. They are as follows:

The TASER Training Bulletin is intended as a "best practices" update for the end user.

It was not intended as an admission of a conspiracy or some type of manufacturer disclosure. I should know since I helped to write it.

The bulletin was based on evolving knowledge of the research available and from field experiences with the TASER devices. I tell people to look at it as if the manufacturer is continually updating information for the end user as a recommendation for best practice.

My colleagues in medicine will understand this because health care professionals are subject to these types of practice updates on a regular basis.

For instance, over the years the practice of CPR has changed and will continue to do so. Every so often the American Heart Association reviews all of the data known about CPR and makes new recommendations about CPR such as the recommended rate of compressions, compression-to-breathing ratio, proper ventilation, etc. CPR in the year 2010 is not the same CPR that was taught in 1980. These changes reflect the best practice of this life-saving maneuver. They do not mean that the CPR performed 10 years ago was harmful. They mean that we now know more information about CPR and have more experience with it to make better recommendations.

Another good analogy to this is automobile airbags.  When airbags were initially introduced in the 1980s, they were installed for the front seat only and came with no recommendations, restrictions, or other instructions for the end user. The motorist simply drove and when an appropriate collision happened, the bag deployed.

As experience and crash data became available, we began to see refinements and best practice recommendations from the auto industry in this area such as advisements about not sitting too close to the dashboard or steering wheel, not storing items that can become projectiles on the dashboards, keeping your hands on the ring of the steering wheel instead of the center where the bag deploys, etc. All of these recommendations came in the form of evolving updates from the auto industry for best practice standards.

These two analogies from other fields show that best practices evolve, which is the reason why TASER sent out its recent training bulletin. I expect that in the future, there will continue to be other evolving recommendations for TASER devices too.

People seem to be fixated to a fanatical degree about TASER devices and risk.

For some reason, many people (including supposed educated experts) expect that the use of a TASER device should equate to a "zero risk" process.

To keep this in perspective, it is important to remember that TASER devices are designed for deployment in very high-risk situations involving acts of violence and aggression. The very nature of the typical scenario means that the situation is already fairly high risk to both the suspect and the law enforcement personnel involved.

A TASER device is a tool of force that is used tactically to gain control of persons that require force to comply with the lawful orders of a police office. People need to understand that there will never be "zero risk" when a TASER device is used.

However, if you look at all of the animal and human study data on this subject and the surveillance data from real field use over the past several years, the risk of an adverse event is really very low when compared with the alternative options. These options include allowing for continued agitation and resistance by the suspect, which would result in profound metabolic acidosis; use of blunt force such as a fist or impact baton that would result in a high likelihood of trauma; use of a firearm that involves a very high probability of death or permanent disability.

When you look at the risk-benefit ratio of TASER device use, it becomes much easier to understand that the risk is acceptable because it is low and the benefit to all involved is high in terms of injury prevention.

The reason that the "Preferred Targeting" zones are now in the training bulletin is primarily for risk management.

In reviewing litigation involving TASER International as well as litigation involving only law enforcement agencies, it seems that the area of the chest is a point of fixation for litigation. If there is a death involved, the argument is that the area of the chest is dangerous and the person's heart was electrocuted. In cases of TASER device use where there is no death, the argument is that because the chest was targeted, there was intent on the officer's part to potentially use this as a lethal form of force from attempted electrocution and therefore the officer used excessive force.

The research data does not support the chest as being a consistently dangerous area to apply a TASER device. There have been cases of abnormal heartbeats from a TASER device applied to small swine, and I would not say that the risk of this is zero in a human.

However, I would say that the human research and field surveillance data of chest applications does not support that this is consistently happening so the risk would be extremely small. In fact, respected researchers in this area state that the possibility of a TASER device application to the chest causing a fatal heart rhythm is in the range of 0.0000014 to 0.000011. This is such a small number that it essentially rounds to zero.

Still despite this extremely minute number, moving the preferred area of aim lower than the chest when possible is a good idea. Doing so neutralizes the entire argument of chest application being dangerous and TASER believes this will go a long way in preventing unnecessary litigation that plagues its law enforcement customers.

Moving the point of aim lower when practical is also an evolutionary best practice from an injury standpoint.

There have been a number of cases where an officer was aiming a TASER at a suspect's center chest and when the device was fired, the dart ended up striking the subject in an area that would be considered undesirable such as the eye, the skull, the throat, and neck.

When the officer targets a subject's chest with the TASER's laser aiming device, the subject often decides to move aggressively toward the officer. Such aggressive moves are typically done by lowering the head to charge at the officer. The officer then reacts to this aggressive action and deploys the TASER device at the subject's center mass. But because the head has been lowered, the top dart strikes the subject in the head, face, or neck.

Lowering the preferred point of aim by a few inches will minimize these types of undesirable shots. Again, this is a best practice recommendation based on field experience. By adhering to this when possible, you are less likely to incur a dart embedment into a sensitive area and this lessens the liability risk for you and your agency.

Lowering the point of aim improves the incapacitation effect of the TASER device application.

Based on experience both in the research lab and in real field encounters, this is another example of how the best practice recommendation is evolving.

One of the most effective applications is to have the TASER darts embed in areas of large skeletal muscle mass. For instance, since TASER International's devices have been in production, the human back has always been taught to be a preferred target area because of all the skeletal muscles located on either side that run the entire length of the spine. These muscles are used for balance and erect posture. When you can affect these with the TASER device, the person loses the ability to stand up and you get the desired effect of causing them to fall down and lose control of themselves. When you don't affect these areas, the person has a higher chance of still being able to continue with his or her undesirable behavior or to remove the darts. Because of this, the back of the subject remains a preferred area for application. There is nothing new about this recommendation.

We have also discovered that for a frontal shot, one of the highest percentages of successful neuromuscular incapacitation occurs when you "split the beltline." That means you put one dart above the belt into the muscles of the abdomen and one dart below the belt into the muscles of the pelvic girdle or the thighs. The muscles in these areas are also used for erect posture and balance.

Splitting the belt line is much more effective than firing the TASER into the subject's chest. In general, the muscles located in the chest are not very large. This means the TASER effect is less likely to incapacitate the subject. There are many reported cases of persons removing the darts from the chest area on their own and continuing their undesirable behaviors. Lowering the preferred target area increases the chance of successful belt splitting by the user.

The training bulletin gives best practice recommendations, not absolutes and does not prohibit shots to the chest.

In other words, the bulletin recommends that the chest is not a preferred target area for all of the reasons discussed above. It does not, however, prohibit chest shots. In fact, it actually recognizes that in many situations, an officer will not be able to avoid a chest shot because of movement, dynamics of the scenario, tactical issues, and/or time. In those situations, there is nothing that states that an application to the chest is off-limits.

As this bulletin was being written, it was recognized that using prohibitive language would only serve to box in officers and make them apprehensive about using their TASER devices. It is unfortunate, however, that many agencies have misunderstood this point and decided to make large, sweeping changes because of this misunderstanding such as removing TASER devices from their officers or writing their policies to be more restrictive. Officer and suspect injury rates will escalate when those types of reactionary and reflexive decisions are made without fully understanding the issue.

What the bulletin does recommend, however, is that when  officers have the luxury of time and can aim to place a shot, they should try to follow the preferred targeting recommendations for optimal results and risk management. This is really no different than saying when you have the time and can line up your shot, you may want to try to target the back with the TASER device because that also has a very high likelihood of best effect. The bulletin is all about improving the user's odds of success while minimizing risk and liability based on evolving information.

The training bulletin is also promoting a universal target scheme for ease of operator use.

TASER International now has several products available for law enforcement use. One of them is the shotgun propelled XREP device, which has the characteristics of blunt impact as well as electrical charge delivery for incapacitation.

When you look at all of the propelled impact tools available (bean bag rounds, ferret rounds, baton rounds, sock rounds, etc.), all of them recommend that you avoid shooting a blunt impact device at the head or chest and that the desired point of aim is slightly lower than that. This is true for the XREP device also and it is not optimal for TASER International to teach officers to aim at different areas of a person depending on which product is in use.

To avoid confusion, it is felt that having a preferred universal targeting scheme for all of its devices would be easiest for the officers to train with, remember, and use. Therefore, it was decided that the training bulletin should give this universal preferred targeting scheme from here on out for all of its devices.

Hopefully, this has helped give you a better understanding of the recent TASER International training bulletin and will allow you and your agencies to make more informed decisions about usage and policy. 

Dr. Jeffrey Ho is an emergency physician at Hennepin County Medical Center in Minneapolis and an associate professor at the University of Minnesota. He also serves as a Meeker County, Minn., sheriff's deputy. An expert in the effect of electronic control devices on the human body, Dr. Ho provides medical direction for TASER International and leads a cadre of researchers who study the medical effects of police encounters and in-custody death.