III - THE DIFFERENT TYPES OF LESS LETHAL WEAPONS

There are many types of reduced lethality weapons, and it would be a challenge to draw up an exhaustive list of them.
One possible classification is to distinguish between weapons intended to be used directly against humans, LLW-AP (anti-personnel - less lethal weapons) and weapons with an anti-material action, LLS-AM. There are, in fact, weapons with reduced lethality designed to neutralize material without destroying it or causing too much damage.

We will quickly review these two categories in order to inform the reader about the numerous researches conducted in this field. We will then focus on a range of kinetic energy LLW-AP whose purpose is to interact more or less violently, by blunt shock, with an individual in order to render him unable to continue his action. It is, whatever one may say and without wanting to reject high technology, the simplest, most reliable and most effective way to neutralize an individual. This is the field of choice for wound ballistics, one of whose missions is to test the lesion potential of the munitions used and to determine acceptable energy levels.

III-1 - ANTI-MATERIAL LESS LETHAL WEAPONS (LLS-AM)

We will start with this category, which we will quickly go through, and expand on the LLW-AP.

LLW-AM, as their name indicates, are intended to disrupt and block the functioning of machines and devices, whether mechanical, electronic or computerized, in order to annihilate the adversary's capacity for action (means of transport, communication, etc.). LLW - AM also target buildings and other structures.

Among the means likely to be used against the rolling stock, one can quote substances modifying the characteristics of fuels, solvents attacking the material of tires, detonating cords breaking the wheels, harrows puncturing tires, hyperfrequency transmitters disturbing or destroying the electronic ignition systems of engines.

Electronic and computer systems can be disrupted or destroyed by high intensity electromagnetic pulses or by the dropping of micro carbon fibers or products highly charged with graphite which will insinuate themselves inside electrical and electronic devices and create short circuits.

Buildings, roads, structures will be attacked with chemicals weakening steel and concrete, dissolving asphalt...

If the direct action of these products is destined to be on materials, the indirect influence on man can not be negligible. Indeed, to speak only about the means of communication and the ways of circulation, their blocking or destruction can involve serious consequences for the populations (famine, deprivation of care...) which, at the origin, were not targeted.

The means of influencing the climate on more or less extended geographical areas are also studied and have probably been used during past conflicts (Vietnam war, in particular).

LLW-AM seem to be intended to be used only in military actions. This is true for many of them, and some countries invest considerable sums in this field of research. However, some LLW-AM are perfectly suited to the needs of civilian law enforcement in peacetime. Examples include vehicle immobilization systems and telecommunications jammers.
Moreover, the internal and external security missions carried out by police forces for some and armed forces for others, often call for the same intervention equipment and generally present strong similarities (anti-terrorism, counter-narcotics, crowd control, etc.).

III-2 - ANTI-PERSONNEL LESS LETHAL WEAPONS

Anti-personnel less lethal weapons are also numerous as there are so many different ways to incapacitate an individual.

III-2-1 - Kinetic energy anti-personnel less lethal weapons (LLW-K)

In the family of less lethal anti-personnel weapons, kinetic energy weapons are ranked at the bottom of the sophistication scale. Indeed, their purpose is to give a shock, a blow to the adversary likely to incapacitate him, to put it simply: to knock him out or in a state close to knockout so that he cannot continue his action. This method of neutralization goes back to the dawn of time.
One condition, however: the projectile must behave as a blunt object and not as a piercing one.
To cause a "simple" pain is generally insufficient as the threshold of perception of this sensation is variable according to the individuals, their state of excitement or their subjection to a psychotropic product (alcohol, drugs...).

These weapons have the advantages of simplicity: they are relatively effective, easy to transport and to use (training in their use is simple), their effects are predictable, and their price is low. They can be provided collectively or individually.
It is for all these reasons that they are finally used so much by the forces of order under the name of Sub-Lethal Bullet Launchers (SLBL) or more simply, defensive bullet launchers (DBL).

The projectiles fired by these weapons are often made of solid or honeycombed rubber, sometimes of flexible plastic, in order to minimize injuries on impact. Indeed, these projectiles, which are supposed to flatten on impact, transmit their impulse over a larger surface than their initial calibre. This reduces the risk of serious damage to internal organs.
There are also projectiles made of an envelope of various materials, rubber, canvas, etc., containing a ballast in the form of powder, lead shot or other component, the purpose of which is also to spread out as much as possible on impact.

The 40 mm launchers, originally designed for military use, require the use of more sophisticated ammunition. The projectiles are made in such a way that the body of the projectile is hard enough to allow it to be rotated by the internal rifling of the barrel and the head is soft enough not to cause serious injuries on impact.

The calibres of the projectiles, all materials combined, of the LLW - AP are variable. We can quote, for the most common ones :

• 9 mm for handguns, sometimes 12 gauge with shortened cartridge (12-50);
  

• 12 gauge (rubber, plastic) for shotguns (single shot, dual shot, buckshot) ;
  

• 37-38 mm caliber designed to fire only less lethal projectiles and differing from the 40 mm launcher, capable of firing less lethal and lethal projectiles ;
  

• 40 mm fired by multipurpose launchers (sub-lethal ammunition, and lethal for war use) ;
  

• 44 mm such as the Flash-Ball, the first SLBL equipped in the French national police force ;
  

• 56 mm for projectiles that can be fired by French law enforcement tear gas launchers.

It should be noted that, until recently, a defensive bullet launcher could be developed in any caliber except 40 mm, in order to remain in the field of LLW and thus avoid the possibility of firing lethal projectiles. In fact, the 40 mm caliber launchers were intended to fire war ammunition, lethal ammunition, including fragmentation grenades. The introduction of 40 mm launchers in the police force shows, to say the least, an evolution in mentalities.

These kinetic energy LLW-AP seem to be disconcertingly simple, even trivial.
However, when these weapons are subjected to extensive testing and evaluation, one realizes that their simplicity is only apparent, and that the exercise of trying to combine in a launcher the qualities of effectiveness and absolute non-lethality, for a range of firing distances sufficiently wide for operational use, is akin to squaring the circle.

This problem is easily explained when one considers that the importance of the lesions generated by these weapons is in close dependence with the kinetic energy of their projectiles or, to be more in agreement with the experimental observations, their impulses or momentum.

In fact, the projectile, like all projectiles, as soon as it leaves the barrel, loses its velocity, and therefore its effectiveness or its danger, depending on the distance of use for which the launcher has been designed.

Clearly, if we study a projectile such that it can neutralize an individual at a distance of 20 meters, thus still possessing sufficient speed to be effective without generating serious injuries to the organs underlying the impact zone, we can bet that at a shooting distance of 2 meters this same projectile will be able to generate very serious or even fatal injuries, given that at this distance it has a much higher speed than at 20 meters.

In a schematic way, we can consider that the ballistic characteristics of kinetic energy LLW-AP must evolve within a more or less narrow zone, the lower limit of which represents the effectiveness threshold and the upper limit the lethality or irreversible damage threshold.

Irreversible lesions pose, in turn, an important problem: which organ(s) should be taken as a reference to evaluate this lesion potential?
If one chooses the liver or the spleen (fragile and highly vascularized organs) all is not lost for SLBL. If it is the eye, we can definitely hang up these defensive ball throwers when we know that a simple tap on the eyeball can lead to retinal detachment.

Hence the need for designers and especially testers of this type of weapon to develop rigorous test protocols in order to eliminate the risks of lethality or serious injury while remaining within an operational logic.

To this end, the testers are tasked with evaluating launchers and their projectiles to determine their lethal potential and to validate (or not) these weapons as meeting the criteria of lessthal or not.
Depending on the request, the testers will be responsible for determining an energy or impulse threshold for operational use.

At present, only lesion ballistics can provide the answer to these questions.

• An example of the LLW-C issue. From Flash-Ball^® to 40 mm defense ball launcher (DBL)

To illustrate this, we'll take two defense ball launchers (DBLs) that are well known in France: the Flash-Ball^® from Verney-Carron and a modern 40 mm launcher, but any 40 mm launcher meets military standards and is of good quality. In reality, we're not really interested in the launchers themselves, since it's not the launchers that cause injury, but the ammunition, and in particular the projectiles.

Flash-Ball^®

The two images below show the compact Flash-Ball and the advanced version, the Flash-Ball Super Pro, which have been successively used by law enforcement officers.

Compact Flach-Ball®		Flash-Ball® Super Pro

First, we'll look at the main projectile fired by the Flash-Ball. This is a spherical, honeycombed rubber projectile with an average mass of 29 grams and a diameter of around 44 millimeters. The figure below gives an image of this projectile. A smooth-bore barrel is all you need to launch it. This is the case with all versions of the Flash-Ball.

Flash-Ball projectile

The projectile looks like a small soccer or handball. This is hardly surprising, given that the ball was originally manufactured in China for use in toys. This explains the significant dispersion in mass and diameter measurements on which we deliberately rely.

The ammunition, of relatively complex design, was highly dispersive in terms of velocity, kinetic energy and momentum. Accuracy became uncertain beyond ten meters, virtually prohibiting reliable use beyond this distance. What's more, the projectile, relatively light for its caliber, rapidly lost velocity and, consequently, effectiveness. Nevertheless, the DBL filled an important gap in law enforcement's defensive capabilities. As a means of intermediate force, it was of undeniable operational interest, provided that a serious evaluation enabled a doctrine of use to be defined. Feedback from the field showed that users were satisfied, and that there were few negative consequences when the gun was fired, especially as the short practical distance at which it was used corresponded more closely to the legal framework of legitimate self-defence.

Originally, the projectile's average kinetic energy at five meters was well in excess of the 200 joules stated in the manufacturer's instructions. We were able to measure kinetic energies of up to 300 joules at a distance of 3 meters. Then in charge of the CREL lesion ballistics unit, we conducted lesion ballistics tests with General Jacques BRETEAU of the French Army Health Service. The results obtained led us to recommend a kinetic energy of no more than 150 joules, taking into account standard deviations in speed.

Anecdotally, this 150 joule limit caused a stir among ALR-C manufacturers, who then set the kinetic energy of their projectiles to this value. It had to be pointed out that this 150 joule limit only concerned a projectile with very specific characteristics, and that for different projectiles (shape, mass, density, calibre, hardness) the maximum acceptable kinetic energy on impact could be very different.

Many criticisms can be levelled at the Flash-Ball ammunition and projectile, especially in comparison with the sophisticated ammunition of modern 40 mm DBLs. The projectile's sphericity and lack of rigidity, which are detrimental to good ballistic performance, nonetheless present an advantage in terms of lesions: no matter how many revolutions it makes on its trajectory, the target always receives the same homogeneous sphere. We don't have to worry about projectile stability.

The 40 mm launcher

The image below shows a 40 mm LBD from Brügger & Thomet.

40 mm Brügger & Thomet launcher with EOTech holographic sight

Please note that the above image is for illustrative purposes only. The rest of the text in no way calls into question this launcher, which we had the opportunity to test and which proved to be of remarkable quality. We would like to remind you that we are only interested in ammunition and, above all, its projectile.

The image below shows two projectiles. These two well-designed projectiles have been deliberately chosen. The aim is to demonstrate the importance of adapting the projectile to the launcher and that, for the same launcher, changing ammunition can produce very different results on target.

Two projectiles fired from a 40 mm DBL

The two projectiles shown above are not spherical. They are gyroscopically stabilized and fired from launchers with rifled barrels. They have similarities and differences.

Similarities

Both are inhomogeneous. The body is made of a rigid plastic material, enabling it to respond effectively to the constraints of internal ballistics, in particular the rifling of the barrel, whose truncations are borne by the integral belt. The front is made of a deformable material that acts as a shock absorber. Its purpose is to limit the consequences of impact damage by absorbing part of the kinetic energy.

Differences

The two shock absorbers, which have the same purpose, are different in nature.

The shock absorber of projectile A is made of a relatively dense material, which has the ballistic consequence of placing the projectile's center of gravity GC practically in the middle.

The shock absorber of projectile B is made of a highly honeycombed material, giving it a low density. This explains why the center of gravity of projectile B is positioned far back. Much further rear than that of projectile A.

Projectile A is shorter than projectile B.

Projectile A weighs 60 grams. Projectile B weighs 33 grams.

Even before carrying out tests, we can assume that the stabilization of projectile B will be more delicate than that of projectile A, given the size and low density of the shock absorber, as well as the more rearward position of its center of gravity. What's more, the axial and transverse moments of inertia of projectile B certainly play against its stability.

The tests below confirm our predictions.

Tests and measurements

The shots are fired on ballistic gelatin. The impact zone is protected by poly-aramid folds to prevent destruction of the gelatin. This protection corresponds to a light garment, but has the advantage of not tearing. The two projectiles are subjected to the same experimental conditions, and we obtain the following results.

The two videos below show the shots.

Initial video observations

Projectile A hits the target without any measurable obliquity. The shock absorber is in a position to fulfill its role: to be less aggressive than the rigid plastic body.

The projectile B hits the target with a high degree of obliquity due to a stabilization fault. It tilts as it interacts with the target. A large part of the impact impulse is transmitted to the target by the rigid plastic body. However, the shock absorber, which appears to be more effective than that of projectile A, is not used correctly.

Important note: it would be a mistake to assume that one bullet is good and the other bad. If you look at them, you'll see that they're both well-designed and probably the result of serious research. The only difference is that one is more suited than the other to the launcher that fired it. The use of a different launcher, for example, with a rifled barrel core with a different twist rate, could have reversed the results.

Video measurement results

The two graphs below, Figures 1 and 2, show the loss of velocity of the two projectiles as they interact with the target.

Figure 1		Figure 2

It can be seen that the loss of velocity is greater for projectile B than for projectile A. There are two reasons for this difference: the difference in mass and the fact that projectile B interacts with the target over a larger surface area, as it tilts almost immediately.

These different speed losses give rise to the decelerations shown in the graphs below.

The two graphs below, Figures 3 and 4, show the deceleration of each of the two projectiles as they interact with the target.

Figure 3		Figure 4

The difference in mass between the two projectiles makes it impossible to judge their potential for injury directly from the decelerations. Instead, we use decelerations to assess the forces at play during interaction with the target. It is these forces that generate potential injuries.

The two graphs below, Figures 5 and 6, show a comparison of the decelerations and forces of interaction with the target between projectiles A (blue trace) and B (red trace). While on the graph in figure 5, the deceleration of projectile B is clearly greater than that of projectile A, the graph in figure 6 shows that the force intensities are closer, given the difference in mass: 60 g for projectile A and 33 g for projectile B. Beyond 1000 microseconds (μs), the traces merge, indicating a similar interaction with the target. However, for the same braking force, projectile A will stop over a longer distance due to its higher mass.

The most significant part of the graphs lies in the time interval bounded by t₁ = 0 and t₂= 350 μs. This is the time interval that will be used to compare the two projectiles.

Figure 5		Figure 6

The peak interaction force of projectile B with the target exceeds that of projectile A by more than 20%. Integrating over the interval t₂ - t₁, we see that the mean value of the interaction force is higher for projectile A than for projectile B. This is illustrated in the graphs in figures 7 and 8 below.

The two graphs below, figures 7 and 8, show, over the interval t₂ - t₁, the area of interaction forces (graph 7) and their average (graph 8).

The graph in Fig. 7 shows, for each of the two projectiles, the area under their corresponding track over the time interval t₂ - t₁ = 350 μs. For projectile A :

Figure 7, bleue area

For projectile B :

Figure 7, red area

I_A and I_B, products of a force by a time, are expressed in Newtons x seconds and have the dimension of a quantity of motion. I_A and I_B are often defined as the impulse of the forces F_A and F_B.

For a better comparison, we can reduce the area of the impulses from projectiles A and B to rectangles whose area is calculated over the period t₂ - t₁ from the average braking force evaluated over this same time interval. For each of the two projectiles :

Figure 8

Figure 7		Figure 8

The average impulse due to the force of interaction between projectile A and the target, over the time interval t₂ - t₁, is 30% greater than the impulse of projectile B. There is no proportionality with their respective masses, as the two projectiles impact the target differently due to the high obliquity of projectile B. Projectile A gives up almost 60% of its momentum in the target in the interval t₂ - t₁, while projectile B gives up more than 80%.

Summary of measures

Projectile A :

Weight : 60 g ;

Impact velocity : 82 ms^-1 ;

Impact kinetic energy : 202 J ;

Loss of kinetic energy between 0 et 350 μs : 169 J soit 84 %. Note: some of this energy is absorbed by the projectile, mainly by the shock absorber ;

Impact linear momentum : 4,92 N.s ;

Quantity of linear momentum transmitted to the target between 0 et 350 μs : 2,95 N.s, soit 60 % ;

Average deceleration force between 0 et 350 μs : 8440 N ;

Total stopping time on target : 3900 μs ;

Average deceleration : 21026 ms^-2 sur 3900 μs ;

Average deceleration force on 3900 μs : 1262 N, 2144 times the projectile's weight.

 

Projectile B :

Weight : 33 g ;

Impact velocity : 85 ms^-1 ;

Impact kinetic energy : 119 J ;

Loss of kinetic energy between 0 et 350 μs : 115 J. Note: the shock absorber played its role incorrectly, given the severe obliquity at impact ;

Impact linear momentum : 2,8 N.s ;

Quantity of linear momentum transmitted to the target between 0 et 350 μs : 2,26 N.s, soit 80% ;

Average deceleration force between 0 et 350 μs : 6480 N ;

Total stopping time on target : 2700 μs ;

Average deceleration : 313481 ms^-2 ;

Average deceleration force on 2700 μs : 1039 N, 3210 times the projectile's weight.

Interpretation of results

A comparison of the parameters characterizing the injury potential of a blunt projectile, i.e. kinetic energy and momentum, shows that those of projectile A are higher than those of projectile B. Only the average deceleration of projectile B is higher, which is normal given its lower mass. Only the average deceleration of projectile B is higher, which is to be expected given its lower mass and, having tilted, its larger surface area of interaction with the target. At this stage of our observations, only the instability of the B projectile could pose a problem if it were to hit an area of an individual's body that is poorly protected by clothing. It is difficult to predict the exact nature of the lesions that could be generated in the superficial planes. Nonetheless, there is reason to fear that cutaneous effraction could occur, depending on which part of the projectile's body comes into contact with the skin. In any case, the shock absorber on projectile B does not perform its function, or performs it poorly.

We can also see that projectile A sinks deeper into the target, as shown in the images below. We can therefore expect deeper lesions with this projectile.

Projectile A Depression ≈ 11 cm	Projectile B Depression ≈ 6,5 cm

Important observations: Important observations: the nature of the impulses transmitted to the target by the two projectiles call for two observations:

• The evaluation of the depression depth presents a bias because projectile B tilts. If it arrived at the target with zero obliquity, we can bet that the depth of its penetration would be greater, without however reaching that of projectile A.

• Analysis of the images above, showing the depth of depression, gives an idea of ??the organs which could be affected by this deformation and possibly be subject to damage. The images do not give us any information about how the linear momentum is transmitted beyond the deformation region. Only the inclusion of pressure sensors or accelerometers could provide us with this important data..

• Note that, during mechanical shocks, soft tissues tend to behave like low-pass filters unlike bone tissue which better transmit high frequencies whose impulse generated by projectile B is richer. Keeping in mind that a deceleration of the projectile corresponds to an acceleration of the anatomical planes underlying the impacted region, we can fear that a sudden deceleration like that of projectile B, could be likely to disrupt the functioning of certain organs, such as the heart, without damage being observed (commotio cordis).

Conclusion

The example we have just studied shows the difficulties inherent in choosing an ammunition adapted to a particular DBL. Sometimes market rules lead to having to change ammunition. The consequences can be harmful if we do not pay attention to the adequacy between the weapon and the ammunition.

The transition from a relatively simple launcher, such as the Flash-Ball, to a more sophisticated DBL makes it more difficult to choose the ammunition suited to the weapon. If the best is not always the enemy of the good, it can make the problem more complex. It must be kept in mind that the stability of an DBL projectile goes far beyond purely ballistic considerations but can have direct consequences on its injury potential.

The attitude (obliquity or not) of the projectile at the time of impact can radically change, at the injury level, the consequences of a shot. Note also that a projectile that is intrinsically stable on its trajectory can be destabilized by contact with an obstacle during its flight.

Any modification in the launcher/ammunition pair is likely to have significant consequences.

• The promise of the future: an acceptable and constant lesion potential over the entire range of use distances

The solution for obtaining acceptable and constant efficiency and injury potential over a wide range of operating distances is through telemetric sighting. The possibility of determining the distance between the shooter and the target will allow the speed of departure, and therefore the impact, of the projectile to be adapted.
This idea is not new. It was held back by technical problems that are now being overcome. There are a few prototypes.

III-2-2 - Anti-personnel less lethal weapons other than kinetic energy

A quick inventory of LLW-AP other than those using the kinetic energy of a projectile can be drawn up, starting with psychological weapons.
Like others, this field is vast, but it is possible to illustrate it with the diffusion, for example, of words, ideas or images that are shocking, or even unbearable with respect to the cultural or religious background of the individuals towards whom they are directed.

The application of psychotropic or strongly sedative products in the form of aerosols has been studied. There is nothing really innovative in this process, as it is in fact only a "softened" version of the use of combat gas.

Biology is not to be outdone. The dispersion of bacterial agents capable of discomforting and weakening a group of individuals for a time is a good way to slow down or even stop an adversary.

Disruption of the senses also offers a wide range of means of incapacitation.
As far as sight is concerned, high-powered flashes or projectors temporarily blinding the individual or stroboscopic light sources set to a specific frequency known to trigger epileptic seizures can be used and some are already used.

More or less discordant sounds emitted by high intensity sound sources quickly become unbearable to the ear. Sounds of high amplitude but of very low frequency (infrasound) can also cause nausea, visual disturbances, disorientation, and possibly lesions due to the resonance of internal organs.

The sense of smell can also be attacked by nauseating substances (hydrogen sulfide, for example) forcing the occupants of an area to leave. Irritant gases (CS, CN, pepper -oleoresin capsicum-) are still widely used.

Faced with this profusion of proposed systems, one must know how to be reasonable. During a conference on lessthal weapons, a manufacturer proposed a very low frequency sound transmitter, in the order of one hertz, which is supposed to 'agitate' and therefore disturb the central nervous system. It was explained to him that, during a jog, the brain of the runner was subjected to a movement of a frequency of approximately 0.5 hertz without causing any inconvenience.

III-2-3 - Electrical pulses weapons

Electric shocks delivered by electronic devices used in contact or at a distance are to be included in the LLW-AP arsenal. In this respect, we can mention the TASER® electric pulses gun which projects two darts connected by conductive wires at a distance and whose trains of pulses, generated at a well-defined recurrence frequency, cause a neuromuscular disruption annihilating any voluntary command of the muscles located in the region of influence of the current. In other words, the intensity of the electrical impulses is such that they take over the neuromuscular action potential.

The marking of individuals with coloring substances, more or less indelible and detectable in the visible or ultraviolet, allows their identification at a distance in time and space.

III-2-4 - No LLW without employment doctrine

This paragraph is short, but it introduces a very important concept: the doctrine of using an LLW.

Given the sometimes narrow line between the threshold of effectiveness of an LLW and that of lethality, in addition to the precision required in the development of this weapon and the rigour of validation tests, an LLW can only be qualified as such if it is accompanied by a doctrine of use. Some services even went so far as to refuse to use an LLW with which they were newly equipped until they had received the doctrine of use.

Cette doctrine d'emploi devait notamment préciser dans quel cadre l'LLW devait être utilisée, la manière de la mettre en oeuvre, les modes d'usages interdits.

For optimal use of an LLW, i.e. maximum efficiency and minimum danger, the user must be both well informed and well trained.

IV - LESS LETHAL WEAPONS, REALITY OR UTOPIA ?

 

IV-1 - Factors modulating dangerousness

If we had kept their original name, "non-lethal weapons", we could talk about utopia.

If we stick to their current name, we can consider that they are part of the reality.

The risk of fatal injury inherent in their use is very low, but not zero. However, we are only talking about direct risks.

In fact, the use of a device designed to puncture the wheels of motor vehicles may not have the same consequences on a four-wheeled vehicle as on a motorcycle. Disabling an engine will not have the same effect on a land vehicle as on an aircraft. Hence the importance of an employment doctrine.

The consequences that can result from the disruption of land routes, radio communications and the climate can be highly lethal: famine, lack of care for the civilian population, impossibility of maintaining order, cities open to organized bands of looters.

The complexity inherent in the use of less lethal weapons is apparent.

The environmental hazard factor has just been highlighted; in one context, some LLW can be used with less risk, in another, it is better to abstain.

Let's take for example an individual or a group of individuals who unduly occupy a premises with the aim of claiming. Faced with this situation, several behaviors are possible.
We can wait for the individuals to get tired and finally abandon the premises, even if they consider that their action has not been entirely successful.
In this case, patience has been a kind of LLW.

If you want them to leave the premises more quickly, you can use a smelly substance that will make them uncomfortable. The premises can be vacated in a few minutes and presumably no one will suffer, except perhaps honor.

Let's put ourselves in another, more pressing situation. We are faced with an excited individual, very threatening. The danger is imminent. We must neutralize him. Whatever the LLW-AP we are going to use (kinetic energy, gas, electricity), we expect a very short response time. The shock, whatever its nature, will have to disturb, unbalance the major physiological functions of the person (breathing, neuromuscular function, perhaps circulatory function), and this in a way that is all the more intense as we want a rapid action on the part of our means of defense. There is a risk, therefore, of approaching the threshold of lethality, especially if the individual is weakened by an illness, stress, psychotropic substances, etc.

IV-2 - The dichotomy between lethal weapons and less lethal weapons. Its reality, its dangers

Strictly speaking, lethal weapons, as opposed to less lethal weapons, can generate lethal wounds even though they are not necessarily sought after. Yet, according to reports from war surgeons, conventional weapon wounds (bullets, shrapnel) are fatal in only 20 to 25 percent of cases. Rates of fatal gunshot wounds are even lower in the civilian sector. Lethal weapons can be cynically considered to have a very poor performance. It is not impossible to imagine that conventional, lethal weapons will be less lethal the more progress is made in emergency medicine. The boundary between conventional and less lethal weapons will become increasingly blurred.
For the time being, this dichotomy is still well entrenched in people's minds. It is not without danger, if only from an ethical point of view, when the police officer, in carrying out his or her mission, has to choose between conventional and LLW weapons.

V - CONCLUSION

The overview of the field of less lethal weapons has shown the advantages they bring in filling gaps in the means of defense or response, opening the way to a continuum between negotiation and use of conventional lethal weapons.

We have also seen that the consequences of their use, depending on the environment in which they are used and the speed with which we want their effects to manifest themselves, are highly variable and can border on the limits of lethality.

They may raise other issues.

If one hesitates to resort to extreme solutions, one will more easily fall back on intermediate means. Their quasi-non-lethality could lead their owners to abuse them, to use them systematically or even as a preventive measure in order to keep groups of individuals and/or entire countries under their control.
Hence the need for greater vigilance and control in their use.
Less lethal weapons, whose purpose is to preserve human life, must not be allowed to alienate human freedom.