Creating Non-Lethal Weapons for the Future

For those who want to gain a deeper understanding of non-lethal weapons technology and safety, I included this appendix. It will introduce you to the general concepts of non-lethal weapons, then walk through a first-principles design approach to building the non-lethal weapons that have the potential to make bullets obsolete in the not-too-distant future. Then I’ll discuss some of the risks that have to be evaluated when deciding to put them to use.

Non-Lethal vs. Less-Lethal vs. Less-Than-Lethal: Three terms for the same concept

A significant amount of confusion and controversy have surrounded the question of what to call weapons that are designed not to kill. The terms “non-lethal,” “less-lethal,” and “less-than lethal” are all terms for the exact same thing: weapons that are designed to deter or stop a threat without killing the target. Sometimes people misperceive these terms to describe varying levels of danger, as if a less-lethal weapon were in a more dangerous category than a non-lethal weapon. This is a false dichotomy. For simplicity, I use “non-lethal” throughout this book, as I believe it is the simplest, most widespread label. It remains the term of choice in both academia and the military.

The Department of Defense defines non-lethal weapons as those “that are explicitly designed and primarily employed to incapacitate targeted personnel or materiel immediately, while minimizing fatalities, permanent injury to personnel, and undesired damage to property.” Nevertheless, non-lethal weapons “do not, and are not intended to, eliminate risk of those actions entirely.”

That last point is very important: the term “non-lethal” describes the intent of weapons that are designed to achieve their effects with a low probability of death or serious damage. However, given the very nature of weaponry, this risk can never become zero.

As non-lethal weapons became widely adopted by law enforcement, the language used to describe them came under much more intensive legal scrutiny, especially in cases in which police departments were sued for the alleged misuse of those weapons. The reason is straightforward: the military conducts operations against foreign adversaries, and hence is rarely the subject of civil litigation in the U.S. courts. Law enforcement agencies conduct public safety activities within the United States and are subject to extensive legal oversight and litigation under the constitutional guidelines that regulate those activities.

While the phrase “non-lethal” might get the point across in plain English, it can be a troubling term in court proceedings. If one interprets “non-lethal weapon” to mean a weapon that will never cause death under any circumstances, it sets a very high bar. As law enforcement agencies began to grapple with cases involving deaths or serious injuries where non-lethal weapons were utilized, the debate over the term “non-lethal” led to the adoption of different terminology, such as “less-lethal” or “less-than-lethal.”

But as I just noted, these terms don’t correspond to any meaningful differences between weapons. In this case, I believe that the clearest distinction is also the most meaningful: the one between lethal weapons (those specifically designed to kill as an intended effect) and non-lethal weapons (those designed to avoid killing, which nevertheless carry some level of risk).

Creating Non-Lethals: A First Principles Approach

Elon Musk, one of the greatest entrepreneurs of our time, has shown an ability to solve seemingly intractable problems across a wide range of industries. He attributes his success to a “first principles” approach.

First-principles thinking means addressing a challenge from the ground up, from the level of the most basic assumptions. Compare first principles thinking with reasoning by analogy, which Musk describes as “copying what other people do with slight variations.”

For example, Musk identified that a requirement for making affordable electric vehicles would be an exponential decrease in the cost of batteries. Rather than starting from the question “what is the cost for commercially available batteries?” and accepting the current prices as limitations, Musk asked a much more basic question: “what are the material constituents of the batteries?” Beginning from that question, he set out to rethink how the materials in batteries could be put together at the lowest cost. Musk realized he could create batteries that were much cheaper than anyone realized, and started toward the vision of his Giga factory.

When thinking about creating non-lethal weapons, I also take a first principles approach.  That means starting with the question, “What exactly is it that we are trying to do when we use weapons? What is the effect we are trying to achieve?”

If we are going to match the capability of lethal weapons, like bullets, then the answer to this question is clear: a non-lethal weapon suitable to substitute for lethal weapons must have the capacity to incapacitate a human target, immediately and completely. And it should do so using an effect that is close to 100% reversible, so that the subject can return to a normal state and a normal life when the incident is over.

Historically, there has been a wide range of non-lethal weapons. However, most of them did not meet this fundamental challenge. The historical menu of non-lethal weapons typically delivered an effect that might deter or dissuade a human target through pain or discomfort. But none of them delivered the ability to immediately incapacitate a focused, aggressive human subject (the type of person who may be on the other side of a violent encounter).

Let’s analyze how we might design a non-lethal weapon to meet these requirements:

  • Immediate (less than 0.2 second) incapacitation
  • Ability to continue or discontinue incapacitating effects for up to several minutes, depending on situational circumstances
  • Full recovery, without long-term impairment, within 10 minutes in over 99% of subjects There are several pathways we can consider toward this goal. Let’s evaluate them in sequence:
  1. Pain. You could deliver a painful effect on the target. This is commonly performed with chemical agents, like pepper spray or tear gas. It can also be delivered using a blunt force striking instrument (like a baton) or an impact projectile (such as a “bean bag” round fired from a shotgun, or a wide variety of wooden, rubber, foam, or other projectiles designed to hurt but not penetrate the body). However, pain effects are limited. While they may prove effective against passive individuals, they are largely ineffective against motivated, aggressive people. It is well documented that, in times of war, even mortally wounded individuals can continue to fight through the pain and injury and return fire. The adrenaline surge of the fight-or-flight response enables people and animals to ignore pain when survival is on the line. A National Institute of Justice study found that, “as an irritant that relies on pain compliance, CN [an irritant spray] is most effective on those individuals who are lucid and have a normal pain threshold. Individuals who are intoxicated, extremely agitated, or mentally ill generally are less affected by the agent because of their greater tolerance for pain.” Pain is a viable approach for some applications, such as clearing crowds of people from certain locations or dissuading behaviors. However, weapons that do not reliably incapacitate their targets cannot substitute for lethal force.
  2. Alternative Stimuli. There has been a wide range of exotic stimuli proposed (or used) as non-lethal weapons. The Active Denial System (see Military Chapter ##) uses electromagnetic energy to create a painful sensation by heating the surface of the skin. Laser dazzlers use bright lights to interfere with night vision, or attempt to disorient or create discomfort. Acoustic weapons play loud noises that can create fear, pain in the ears, or even attempt to induce nausea. Whether these alternative mechanisms stimulate pain, temporary blindness, nausea, or any other sensation, I do not believe they have the ability to incapacitate a motivated subject. Pain is likely the most influential sensory effect of stimulation, and we know that pain might dissuade a person, but it is not enough to incapacitate them. These alternative stimuli can be distracting or unpleasant. They may have utility in achieving certain objectives, such as deterring or dispersing a crowd. While they may work as a non-lethal instrument, they do not achieve a meaningful alternative to lethal force due to their lack of ability to incapacitate.
  3. Mechanical Restraint. Handcuffs are a widely used and highly effective means of impairing a person’s ability to assault another. However, the application of handcuffs is a fairly precise procedure, and can normally only be completed once a subject is under physical control. There is a wide manner of physical restraint techniques such as “judo holds,” which allow one person to physically restrain another person using only his or her body parts. This grappling ultimately turns into a competition based on the strength, skill, and motivation of the participants.  These capabilities, even in the most skilled martial artist, are not suitable to restrain a dangerous, especially an armed assailant. From thrown nets to Spiderman’s fictional webs, there have been many concepts for launchable restraints.  One of the more creative approaches was “Sticky Foam,” a project at Sandia National Laboratories that sought to create a “gun” which could fire an adhesive foam that could adhere to a human target, effectively incapacitating him. Sticky foam had a number of drawbacks, including the risk of getting the adhesive into the subject’s airway, which would cause suffocation. Another recent development is the BolaWrap,™ a device that fires a Kevlar cable to entangle the legs of a subject. While there have been many creative attempts at nets and capture devices, none has proven to be practically useful to date (evidenced by no such systems in widespread deployment). Throwing or launching a physical restraining device around a moving, resisting subject has proven a difficult technical challenge.
  4. Physical Injury. You could also deliver an effect that causes physical injury, such as a baton strike that mechanically breaks bones. I won’t spend much time on this one, as the drawbacks are pretty obvious. If the goal is to have a temporary effect, causing physical injury is a brute force approach that will be inherently difficult to control in a manner that avoids both permanent injury and death. Some injuries caused by a baton strike might heal over time—but some might not. Some might even be fatal.
  5. Death. This approach obviously flies in the face of our stated objective. But it’s worth noting that lethal weapons can fail the test in two ways. Not only do they kill their targets—the obvious way they fail our test—they can also fail to incapacitate them quickly enough. According to FBI Special Agent Urey W. Patrick, who wrote “Handgun Wounding Factors and Effectiveness” for the FBI Academy in Quantico, Virginia, only a direct hit to the brain will cause instant incapacitation. Even a shot to the heart will allow a subject to return fire for 10-15 seconds. In other words, even lethal weapons do not reliably deliver instant incapacitation.
  6. Command and control. As Special Agent Patrick writes in the FBI study on lethal force, “The human target can be reliably incapacitated only by disrupting or destroying the brain or upper spinal cord.” In other words, the way to immediately incapacitate a subject is to take out the command and control systems of the body. Historically, this has been done by physically destroying the command and control center, the brain. Otherwise, even lethal shots won’t stop the recipient in the short term. They may die eventually, but if they shoot back and kill you first, there is little solace in the eventual outcome.That’s the objective of a perfect weapon, whether lethal or non-lethal—disrupting or destroying the body’s command and control center. We know how to do it through lethal, physical destruction. Can we envision a method to take out command and control without death and destruction? If we can, we’ll have solved the problem of non-lethal weapons and met our objective.To do this, we need to understand how the brain controls the body. Fundamentally, it’s pretty simple. The brain is a giant cluster of nerve cells. It connects to an enormous number of nerve fibers that run down the spinal cord and out to the rest of the body. We can think of the command and control system (the nervous system) in three main parts: the central nervous system, the sensory nervous system, and the motor nervous system. The central nervous system is the brain and spinal cord. It calls the shots, does the thinking, makes the decisions, and issues the commands.The sensory nervous system includes all of the sensors that collect information about the world around us and the nerve fibers that carry that information back into the brain. The eyes and the optic nerve collect light information and transmit it to the brain, giving us sight. The ears and the related auditory nerves do the same with sound waves, giving us hearing. Sensors in our skin pick up touch, heat, cold, and pain. Taste and smell make up the balance of our five senses. Most non-lethal weapons throughout history have focused on the sensory nervous system. It’s pretty easy to get to it—because all the elements of the sensory nervous system are readily accessible. They are on the outside of our bodies, looking to be stimulated, actively monitoring for things to sense. So it’s pretty straightforward to stimulate pain (heat, chemical irritants, impact), sound, sight, smell, etc. However, as discussed above, our brain is quite talented at tuning out the senses when it’s time to fight or run away, or when our survival is generally perceived at risk. The motor nervous system includes the nerves that transmit the commands from the brain to control the muscles. All of our physical movement is controlled by our muscles. Diseases such as amyotrophic lateral sclerosis, or ALS, destroy the motor nervous system’s ability to control our muscles, as the world painfully observed over the life of Stephen Hawking, who became completely immobilized and unable to control his body, including the ability to speak. But what if we could temporarily shut down, or at least interfere with, the motor nervous system in a way that could incapacitate someone for a period of time, but then allow them to fully recover? It turns out that stimulating the motor nervous system is much harder than stimulating the sensory nervous system. The motor nerves are not sitting near the surface, “looking” for stimuli. They are buried deep in our bodies, protected beneath layers of skin, fat, muscle and bone. To function properly, these nerves need to be protected so that the signals from the brain to control our body are safely and securely delivered without interference. (One area of deficiency in this protective design is what we call the funny bone, where the ulnar nerve is trapped between the skin and the bones of the elbow joint. An errant bump of the elbow can impact the nerve directly—with striking effects on both sensory and motor function for a few minutes.) Let’s return to first principles. How does the motor nervous system work? For all its amazing complexity, the motor nervous system functions via two general mechanisms: chemical and electrical. Chemical: We can think of nerve cells a bit like biological transistors. They switch on and off, passing information around the body. Where two nerve cells meet, the junction is called a synapse. At the synapse, chemicals are released from one nerve cell, and those chemicals stimulate the nerve cell on the other side. We can influence the nervous system through various chemicals, such as anesthetics or paralytic agents. If you have ever had surgery, you have experienced a chemical influence that shut down consciousness across your central nervous system. There are also specific chemicals that can impact certain types of nerve synapses. For example, curare is a chemical used as a poison in Central and South American cultures. Curare specifically blocks the junction between nerves and muscles. Someone experiencing a dose of curare will stay fully conscious, but will lose muscle control. Without medical assistance, they can die by asphyxiation due to paralysis of the diaphragm.There are a wide number of chemical agents we could use to impair someone’s nervous system, but there are only a few ways you could deploy them: primarily through injection or inhalation (or perhaps through skin contact or ingestion).
  1. Tranquilizer darts: used frequently for subduing wild animals, or large animals in zoos, darts can inject a tranquilizing drug into the subject, usually using an intra-muscular pathway. Injecting a drug into the muscles is a slower pathway to effectiveness than injecting it right into the veins because it takes some time to absorb. That’s why lions you might have seen tranquilized on a nature documentary kept running around for a while before they collapsed. But it’s essentially impossible to hit a moving target in a vein, meaning that instant incapacitation is out. It’s also difficult to control the dosage relative to body size and to predict allergic and other reactions. In conversations with animal control specialists, we have heard anecdotally that tranquilizer darts have a reasonably high fatality rate, on the order of 10%. (Jimmy Soni can we get our researcher to get us a number?)
  2. Inhalants: Some nerve agents can be formulated as inhalants – they are called nerve gases. Some may also be combined with chemical formulations that may allow them to transmit transdermal (through the skin).
    1. Lethal: Most nerve agents that have been created as weapons have been intended for lethal use. Nerve agents typically disrupt the motor nerves at the synapses by preventing the nerve cells from functioning properly. A normally functioning motor nerve releases a chemical called acetylcholine, which stimulates the next nerve cell across the synapse. Almost immediately, another chemical breaks down the acetylcholine to stop the stimulation and clear the synapse for the next signal that may come along. Nerve agents typically stop the clean-up process, so the stimulating acetylcholine stays in the synapse, causing continual stimulation. The result is a continuous stimulation that causes seizure-like activities and loss of bodily control, ending in asphyxiation and/or cardiac arrest. Fortunately, nerve agents were not discovered until 1936, precluding their use in WWI. Although Nazi Germany is thought to have produced up to 10 tons of Sarin nerve gas, it was not used in war and the allies did not learn of these agents until shells filled with them were captured at the end of the war. But Sarin gas has been deployed, with lethal effects, in a Japanese subway terrorist attack in 1995, and in the city of Ghouta in 2013 during the Syrian Civil War. Obviously, it’s off the table for our purposes.
    2. Non-lethal: In theory, inhalants similar to nerve agents could be developed for the intended use of delivering a non-lethal effect. More than theory, this approach was attempted by Russian special forces attempting to rescue 850 hostages from 40–50 armed Chechen rebels who had seized control of a Moscow theater on October 23, 2002. On the fourth day of the siege, Russian special forces pumped an aerosol anesthetic, reported to be based on the drug fentanyl, into the theater. The effects were neither immediate, nor very safe. It killed a number of hostages and failed to kill or incapacitate many terrorist fighters (apparently some had gas masks). In all, about 200 people died in the raid. Given that the special forces had days to prepare and deploy the gas in a confined space, the lack of effectiveness combined with the high level of lethality indicates, to me, that designing a non-lethal nerve agent would be very difficult indeed.


Electrical
: Back to our analogy that nerve cells are like transistors. While chemistry rules the day at the connections between nerve cells, it is electricity that transmits the signals along nerve fibers. It’s fascinating to learn how waves of electricity pass down the length of a nerve. But that’s more technical than required for our purposes here. The main point is that we can impair the command and control systems of the human body by electrical means that stimulate motor nerves using the same mechanism of their normal function.

Electricity has some real advantages. Its effects are immediate—there is no waiting for it to take effect. Dosing can be controlled electronically, allowing precise measurement and adjustment. Electricity also has a very large safety margin. As you will see below, the difference between the effective dose and a potentially lethal dose is more than 10-fold, meaning that we should be able to design a weapon that has enough electrical charge to be highly effective while maintaining a significant margin of safety to avoid dangerous unintended effects.

A 1976 report from the U.S. Army Engineering Laboratory at Aberdeen Proving Ground, Maryland, concluded that electrical weapons offered many advantages over existing chemical and kinetic energy weapons: “Some of the advantages are: Broad spectrum of incapacitation, predictable physiological effect, controllability of dose, rapid incapacitation etc.” Nevertheless, public aversion to electrical weapons in the U.S. was pervasive, limiting research and development.

In summary, electrical weapons stand out as the most promising route to a truly effective non-lethal weapon, based on first principles analysis.

Electrocution Effects on Humans | Rick Smith, The End of Killing

How to Design a Non-Lethal Electrical Weapon

When we first learn about electricity, it is usually a case of our parents warning us about its dangers. But we usually aren’t given much information about why and how electricity is dangerous. For example, it’s a myth that high voltage is dangerous. This is not accurate—the electric current, measured in amperes, determines the level of danger.

Myth: High Voltage is Dangerous | Rick Smith, The End of Killing

In this photo, a woman and daughter are experiencing about 20 million volts at a science museum. Their hair is standing on end, but there’s no current flowing, so there’s no harm to them.

Electrocution Water Analogy | Rick Smith, The End of Killing
Electricity is a flow of electrons through a material. Since you can’t see electrons, it’s helpful to use the analogy of water flowing through a pipe. Voltage is the water pressure. On the left, you have a lot of water pressure, but the valve is closed: voltage is high, but the current is zero (there is no flow occurring). On the right, the valve is open, which allows the water pressure to push water through the pipe, creating a current. The flow of electric current is measured in amperes. Current describes how many electrons are flowing through the circuit, just as the pictures above depict water flowing through a pipe. The key fact is that the current is the key for both effectiveness and safety.

C.F. Dalziel Study | Rick Smith, The End of Killing

Regarding the effects of electricity, some of the pioneering work on the effects of electricity was conducted by a researcher named C.F. Dalziel at Berkeley in the 1940s and ’50s. Dalziel conducted a study in which he had students hold onto two electrodes. He would then slowly turn up the electricity and observe the effects. Note that the scale shown above is logarithmic: it is increasing in multiples of 10, from 1 to 10 to 100 to 1,000. So for each major tick, the current goes up 10 fold. At the lowest levels, there was zero effect. As the electric current was increased, there was a threshold of sensation at which people would begin to feel a tingling. As the current was increased further from 1 milliampere to 10 milliamperes, the tingling intensified and became painful. This was the “pain” threshold. As the current was increased, the students reached what Dalziel called the “let go” threshold: the electrical effect reached a point where the volunteer could no longer let go of the electrodes. The electrical current was stimulating the muscles to contract, and the student could no longer choose to let go of the electrode. The “let go” threshold is where uncontrollable contractions occur. If you continue to increase the current, you eventually hit a threshold where breathing stops, and finally, you get to the risk of ventricular fibrillation, also known as sudden cardiac death. Note that the risk of ventricular fibrillation is about 10 times above the let go threshold. This is a key point: it’s one of the facts that makes electricity a really powerful technology for incapacitating someone while minimizing risk. There’s a pretty big safety margin between the level that can cause muscular impairment or neuro-muscular incapacitation and the level at which there’s a significant risk of a lethal cardiac event.

Dose Response: TASER X26 | Rick Smith, The End of Killing

This next chart is from one of the early studies of the TASER X26 that showed the same phenomenon in laboratory testing using an anesthetized swine model. Along the bottom axis is the electrical charge per pulse (when you add up the electrons in all the pulses delivered each second, you would get the current). Just to simplify things, the bottom axis is also directly proportional to the relative current being delivered. The green line at the left shows the electric charge or current levels where the muscles were contracted—this is the desired effect at which the TASER device was causing the Neuro-Muscular Incapacitation. The researchers then were able to increase the output of the laboratory test device until it did cause ventricular fibrillation— this is the plot in red.

The difference between the effective dose from the TASER test device and the potentially lethal dose was about 16 times—meaning you had to increase the output to 16 times the TASER dosage until the device would causing sudden cardiac death. So this is a very significant safety margin. By way of reference, there are some over-the-counter medications that have a much lower safety margin. For example, Tylenol (acetaminophen) has a safety margin of only about 8 times, meaning that an intake of eight times the maximum recommended dose can be potentially lethal.

This is one of the things about the TASER CEW (Conducted Energy Weapon) that is quite remarkable: we can take advantage of this high safety margin between the effective dose and the lethal dose. It’s the safety margin found by Dalziel many years ago, re-engineered into an incapacitating weapon.

But while the TASER CEW has a significant cardiac safety margin, it’s not risk-free. So let’s talk about relative risk, and risk in general.

Relative Risk

The number one cause of death in the United States is sudden cardiac death. And I want to be really clear that we’re not talking about anything to do with TASER or electrical weapons right now. We’re talking about general causes of death in the U.S. Number one is heart disease:

specifically within the category of heart disease, over 325,000 people experience sudden cardiac death each year.

Causes of Death in United States | Rick Smith, The End of Killing

If we add up all motor vehicle deaths, drug overdoses and firearm deaths in the United States, we’d still get less than half of the number of sudden cardiac deaths.

So what causes sudden cardiac death? Many things can contribute: for instance, long-term conditions like obesity, smoking, and stress that cause heart disease and put you at risk. But the moments that trigger a sudden cardiac death event are frequently related to stress and exertion.

That’s why we see Automatic External Defibrillators (or AEDs) in gyms and at airports and golf courses. These devices are remarkable lifesavers—you should know that sudden cardiac arrest is highly reversible if you have an AED.  In fact, for many types of cardiac surgeries, a surgeon will use electricity to fibrillate the heart, do the procedure, then use a defibrillator to put the heart back into a normal rhythm with a reliability of virtually 100%.

Today, about 10% of sudden cardiac arrest victims are successfully revived with a defibrillator. You can reverse a very high percentage of these cases, but only if a defibrillator is used within three to seven minutes. (That’s one reason every police agency should strongly consider having defibrillators in their patrol cars. If officers come across somebody who’s collapsed in sudden cardiac death, an AED would give them the ability to save them.)

So, if stress can be a trigger of sudden cardiac death, we should consider this question: “How stressful is a forcible arrest?”

It’s probably one of the most stressful things any human being can go through. You have the physical struggle, which can be extreme as people fight to exhaustion. Think about the adrenaline surge for someone worried about having their freedom taken away and going to jail. It’s extremely stressful. Add in the fact that many people who are forcibly arrested might have mental health issues, or might be under the influence of drugs. Any time police are making a forcible arrest, there’s a significant risk of a sudden cardiac death just from the stress and the exertion of that event. Obviously, few of the sudden cardiac deaths represented in that chart come from forcible arrests.

Causes of Death in United States | Rick Smith, The End of Killing

Can electricity cause sudden cardiac death? Yes—in sufficiently high doses. However, electricity is a very small fraction of sudden cardiac death cases. For example, if we add up all electrocution deaths in the United States in any given year, we get a little over 300. Fewer than 1 out of 1000 sudden cardiac deaths could even be electrocution—and most of those cases are caused by industrial accidents with high currents. The point is that while there’s a lot of focus on the dangers of electricity, on a practical basis electricity of all kinds accounts for a very, very small percentage of sudden cardiac death events.

Deaths Involving TASER CEW Use | Rick Smith, The End of Killing

Now let’s pivot and let’s talk about how many deaths involve TASER CEWs. Around the world, there are about 50 to 100 cases each year. Those numbers include all cases, whether the TASER weapon contributed to the death or not. As we’ve seen, somebody who is being forcibly arrested is already under high stress, and may be subject to many other aggravating factors.

In the significant majority of those cases medical examiners did not find that the use of a TASER weapon significantly contributed to the death. It’s true that, in a fraction of these deaths, the CEW does play a role. Those cases are typically related to injuries from falls and ignition of flammable gases or liquids. There is quite a bit of controversy about whether a CEW did or did not play a role in sudden cardiac death in some cases. So can a TASER weapon cause sudden cardiac death when used properly? It is possible, but the science indicates it is a very rare possibility.

As I’ve mentioned, the TASER weapons have been designed to have a very high safety margin. However, the risk is not zero. The theoretical risk of electrically induced ventricular fibrillation from a CEW is less than one in one million uses. But if the current does not go across the chest, then we can say more definitively that the risk of a direct electrical cardiac effect is zero.  This is one of the reasons we advise avoiding aiming at the chest when feasible.

Risk of Death | Rick Smith, The End of Killing

Now let’s put this into an overall framework to help calibrate levels of risk. Across the entire U.S. population, the risk of sudden cardiac death is about one out of every 1,000 people. College athletes are healthier than the average person, but engaging in college-level sports involves a high level of stress and exertion. According to NCAA statistics, about 1 in 3,000 Male Division I basketball players will experience sudden cardiac death.

If you drive a car for a year, you are exposing yourself to a risk of about one out of 6,700 that you could die in any given year. For the average American, the risk of dying in a plane crash is one in 774,000. The risk of being killed by lightning is 1 in 13 million.

Now let’s consider specific public safety technology. According to data from the hospital at UCLA, one out of every two gunshot victims die. The ACLU of California published a study finding that about one of every 600 people exposed to pepper spray die (though, again, it’s unclear whether pepper spray directly caused those deaths).

Similarly, if we look across all CEW incidents we see that about one out of 3,500 incidents involves a death. That takes into account all deaths from all causes—including the majority of those, which are not related to the use of the TASER weapon itself in terms of the cause of death.

The chart above breaks down TASER weapon-related deaths in more detail. The chance of being killed by a fall after being hit with a TASER weapon is about one in four hundred thousand.  The risk of a CEW causing ventricular fibrillation is somewhere less than one in one million uses. CEWs causing the ignition of a flammable that resulted in death is about one in one and a half million. As the chart shows, the risk of death in an incident involving a TASER weapon is about the same as the risk of a college athlete collapsing from sudden cardiac death. And the risk of a TASER weapon directly causing death is about the same as the risk of the average American dying in a plane crash— pretty remote. But it’s still not to be taken lightly, and it’s best avoided by training any law enforcement officers who use TASER weapons in comprehensive safety protocols.

For instance, the most important thing police officers can do when they arrive on a scene is to look for the danger signs indicating that the subject might be in a medical crisis (for instance, the subject is naked, sweating, doesn’t appear to feel pain, is having trouble breathing). If any of these danger signs are present, they should call for medical backup even before engaging, if time and circumstances permit. In fact, many agencies are making it standard practice for dispatchers to send medical support if they hear any of indications of those danger signs in the initial call. When training law enforcement officers in safe TASER weapon use, we also teach them de-escalation techniques that can help secure voluntary surrenders and make it more likely that no weapon needs to be used at all.

Perhaps the best synopsis of the relative risks of TASER weapons comes from a 2005 study by the Potomac Policy Institute, “Efficacy and Safety of Electrical Stun Devices.” The study generated a novel insight, comparing electrical stun devices to another life-saving device which sometimes can cause unintended deaths, the automotive airbag. The conclusion: taking into account the cases in which they prevent the use of lethal force, electrical stun weapons likely have a higher ratio of lives saved to lives lost than automotive airbags. Here’s how the study put it:

We found a fundamental FDA philosophy to be useful for evaluating the safety and effectiveness of devices such as stun guns. This methodology considers the risks associated with a device relative to its efficacy, and considers no product to be completely devoid of risk.

Key Conclusion: Based on the available evidence, and on accepted criteria for defining product risk vs. efficacy, we believe that when stun technology is appropriately applied, it is relatively safe and clearly effective. The only known field data that are available suggest that the odds are, at worst, one in one thousand that a stun device would contribute to (and this does not imply “cause”) death. This figure is likely not different than the odds of death when stun devices are not used, but when other multiple force measures are. A more defensible figure is one in one hundred thousand.

Stated another way, the probability of death after stun device administration to the body is from one in a thousand to one in one hundred thousand. Looked at from a different probability perspective, the likelihood of death due specifically to airbag deployment in modern automobiles is such that for every 50 individuals saved, one is killed. One stun device manufacturer claims that stun devices have saved some 7,000 lives. If true, the most conservative saved/killed ratio for stun devices is 70:1. Based on the data cited above, this number is more likely 700:1 or greater.

The point is that no weapon can be 100% risk-free, just as no pharmaceutical can be 100% free of side-effects. The real challenge is to manage risk, making tradeoffs that are worth it and save lives in the long run. Let me close this chapter with a story of risk-management gone wrong.

Introducing Low-Risk Weapons into High-Risk Environments

On October 14, 2007, Robert Dziekański, a Polish immigrant to Canada, was acting erratically after his arrival in the Vancouver airport. He arrived around 3:15 pm, and wandered around the airport for the next 7 hours, appearing dazed and visibly agitated. At one point, he threw a computer and a small table to the floor. As police engaged with Dziekański, he picked up what appeared to be a large stapler and held it in a throwing position and was subsequently hit with a TASER M26 weapon by officers of the Royal Canadian Mounted Police. Shortly thereafter, Dziekański died.

The incident garnered immediate and global media attention and led to diplomatic strain between Poland and Canada. There was widespread condemnation of the RCMP and of the use of the TASER weapon, which the media assigned the clear blame for the death of Mr. Dziekański.

In response to the incident, the Braidwood Inquiry, headed by a retired court of appeal justice Thomas Braidwood, was established by the British Columbia government in order to inquire into the use of Conducted Energy Weapons (CEWs). Proceedings began on January 19, 2009 and continued until the final report was released 18 months later, on June 18, 2010.

Throughout the year and a half duration of the Braidwood Inquiry, the tone of the proceedings was one of assured guilt: that the officers had killed Dziekański with the use of the TASER weapon. The inquiry was regularly front-page fodder on the Vancouver Sun, and the inquiry ultimately came to a conclusion that a TASER weapon might cause ventricular fibrillation (VF, or sudden cardiac death).

During this time period, there was a distinctive chilling effect, in which agencies across Canada stopped deploying new TASER weapons and put more significant restrictions on their use.

But the Commission left out one important detail—in fact, it suppressed the evidence of an important detail for more than a year. The TASER weapon did not cause VF in Robert Dziekański. For more than a year, the Braidwood Commission was in possession of multiple autopsy reports that showed Dziekański was suffering from “asystole”—a heart arrhythmia different from the ventricular fibrillation that electricity might cause. In fact, multiple autopsies performed on Dziekański found the death was consistent with the effects of chronic alcoholism and preexisting heart conditions, exacerbated by the stress of his arrest. The important point is that Dziekański died from an arrhythmia that cannot be caused by an electric shock.

But the findings from the autopsies clearly didn’t fit the political and media narrative of outrage, so they were kept under wraps until the process was all but complete. The Commission ultimately did not conclude the TASER weapon killed Dziekański, but it did nothing to undo the public narrative that it had. In fact, the Commission wrote a generic opinion that an Electronic Control Device could cause VF, although the evidence, in this case, pointed in a very different direction.

The death of Robert Dziekański was a tragedy. There is no disputing the pain and suffering of his family. However, the fact that his death was loudly and publicly (and wrongly) blamed on a weapon the RCMP officers used in an attempt to subdue him without resorting to more injurious force was both misleading and counterproductive. The findings of the Braidwood Inquiry substantially stalled deployment of TASER weapons across Canada for years to come, all based on the false perception that still holds for most Canadians today: that the RCMP killed Robert Dziekański with a TASER M26.

Without that false perception, the February 2014 shooting of Alain Magloire might have been avoided. Magloire was a 41-year-old man with mental health problems who was wielding a hammer in Montreal. None of the police officers on the scene had a TASER weapon, and instead, he was shot to death. Magloire’s brother, Pierre, protested that “it’s unacceptable that a policeman who’s doing the first intervention has to call another policeman to come help with a TASER gun.” Magloire was shot before an officer with a TASER weapon could arrive on the scene.

Similarly, on July 27, 2013, Toronto police shot and killed 18-year-old Sammy Yatim, who was armed with a switchblade. At the time, Ontario police were operating under strict restrictions limiting TASER weapon use to a limited set of supervisors. If the responding officer had been equipped with a non-lethal weapon, Yatim might have lived.

The political circus of the Braidwood Inquiry had put the brakes on TASER weapon deployments across Canada. We won’t know if the Magloire and Yatim incidents may have turned out differently, but you can probably guess my opinion.

My point in sharing the parable of the Braidwood Commission is to illustrate the difficulty in introducing new approaches into high-risk situations. By their nature, high-risk scenarios involve significant risk of death or serious injury.

Imagine a new medical breakthrough that could cure half of the patients diagnosed with pancreatic cancer, a disease that kills 74% of people within a year of diagnosis. The question we’d ask in evaluating that breakthrough isn’t, “is it free of side-effects?” It’s “does the chance of saving lives outweigh those side-effects?” If the answer is yes, we’d certainly hope that drug regulators would allow doctors to prescribe the treatment as soon as possible.

I’m simply asking that people think of non-lethal weapons the same way.