Automatic warning system of assaulting police officers

In the depths of the German Interior Ministry there was a leak in the form of a Power Point presentation about a previously unknown research program aimed at creating an automatic warning system about an attack on police officers. From the available slides, it can be concluded that at the moment the project is at the stage of development and testing of the prototype.

main idea

In the event that a police officer is attacked, this should be reported automatically to the central console. This system can save the life of a policeman if he is alone and wounded leads to loss of consciousness. Under normal conditions, the policeman is threatened with death due to large blood loss. The new system will report not only the fact of the attack, but also the location of the policeman, the position of the wound on the body, his pulse, body temperature, etc. She will also tell you if a bullet wound is a through wound or a bullet is stuck in the body. Moreover, not only the number of bullets will be reported, but also their caliber (only a rough estimate is currently possible here). Theoretically, you can even determine the number of attackers. There will also be taken and sent photos and sound recording from the crime scene. The system distinguishes between knife and bullet wounds.

The system will also report to the post about the incident, not only if the policeman was shot, but also if the policeman himself shot.

And now a little about how it all works. Technical details are not known, there is only a rough description of the main ideas.

The system will consist of several subsystems. Each of them is independent of other components and provides quite a bit of information. But by combining data from several sources, it is possible to make quite interesting and important conclusions about what is happening or was happening with the police.

So, the system consists of the following components:

Body armor

The first system is embedded in a standard police bulletproof vest. Her task is to tell whether the policeman was shot at, and if so, what the consequences were. Currently, several approaches are being tested to solve this problem.

As already mentioned, the technical details are unknown. We can only talk about general ideas.

So, the first approach to solving the problem. Between the outer and inner layer of matter and armor plates there is a layer of metal mesh.

In the event of damage, the system will accurately determine the location of the armor plate breakdown by “ringing” the grid. If the outer layer of the mesh suffered, there was contact with the bullet. The size of the cliff can be judged on its caliber.

If there is also damage on the inner layer, then the bullet passed through the armored plate and, accordingly, we can speak about a gunshot wound. If there is damage to the internal mesh on the other side of the body, then the wound is a through wound. Determining the difference in time when the gaps were formed, you can determine the direction of flight of the bullet. For example, if at first there was a gap on the back, and then on the chest, then they shot exactly from the back. Moreover, knowing the position of the breaks, it is possible to determine the trajectory of the bullet in the body and thus predict possible damage to internal organs.

This solution works well for firearms because it has great energy and is guaranteed to damage the mesh. In case of a knife strike, the system may not receive enough damage to reliably determine the attack. Yes, the knife does not penetrate the body armor, but the attack must be reported, so the system must reliably recognize such cases.

The second approach significantly improves the ability of the system to recognize an attack with low-energy weapons, such as a knife. Under the top layer is a layer consisting of two components

  1. a layer of polyethylene with small bubbles of liquid (in the figure a layer of yellow)
  2. a layer with a material that, when wet, begins to conduct electricity (in the figure a layer of red).

The principle of operation is very simple. The knife pierces a bubble of water, water wets the next layer, which begins to conduct electricity. "Calling" you can find out where the puncture occurred.

The principle of operation of the layer, which determines the place of “leakage” from the layer with liquid, unfortunately, is not explained.

Another option takes into account the fact that, as a rule, bullets and knives are made of metal. At the time of contact, the total capacity of the system should increase abruptly. By measuring the capacity of different areas of the systems, it is possible to identify the area with the change. So the place of contact will be determined.

These two approaches provide a fairly high degree of reliability in recognizing attacks on a police officer. But that is not all. There is one more component. On the vest there are several microphones that constantly listen to external sounds. Special software responds to the sound of a shot. If in a short period of time there were recorded breakdowns of the body armor and a shot of sound, then it can be said with a sufficiently large guarantee that they are interrelated. Knowing the time difference, you can determine the approximate distance at which the shot was fired. Having data from multiple microphones, you can triangulate the location of the shooter. Having a record of the shot, you can try to determine the brand and model of the gun.

There is also an idea to use cameras on the back and chest, which take pictures to detect an attack.

Pistol and Holster

Now let's talk about the system, which finds out that the policeman shot. In the gun shop there is a small sensor that says that the store has one less cartridge. If at the same time the microphone system says that it spotted the sound of a shot, then the policeman fired a shot, which will be immediately reported to the central post.

Another system monitors the pistol holster. Several sensors report whether the gun is in a holster or not. In addition, they measure the method and speed of pulling out a pistol. In different situations, this happens in a special way. For example, when a policeman pulls out a pistol in a dangerous situation or when he pulls it out for surrender to an armory.

Wrist tracker

To reduce the likelihood of an error, another component will be used: a special wrist bracelet. The bracelet can play the role of a watchband. In the bracelet sound sensor, accelerometer and compass. At the moment of the shot, the hand twitches that the accelerometer notices. Shot sound time must also match. If the sensor in the store says that there was one less cartridge, then it can be argued that the policeman fired a shot.

There is a magnetic compass in the store, so you can always see which way the shot was fired. By combining this data with the accelerometer reading in the wrist strap, you can quite accurately reproduce the trajectory of the shot. Naturally, the readings of the compass in the strap and in the pistol shop should coincide to a certain extent.

By combining the data from the sensors of the holster and from the sensors on the wrist, it is possible to determine whether the policeman pulled the pistol, or if the pistol was taken by an outsider. For example, the holster reported that the gun was taken out, and the sensor on the wrist said that the hand was stationary. In this case, you can safely sound the alarm, because it is quite possible that the policeman does not control the situation and has just been disarmed by third parties.

One of the slides mentions the possibility of “tying” the pistol and the wrist tracker by determining the distance between them. If the gun was taken out of the holster, but it is too far from the wrist tracker, then this is interpreted as not a standard situation. Separately, the moment is considered when a police officer - right-handed with a tracker on his right hand took the gun in his left hand. According to the logic of this subsystem, this is a non-standard situation and an alarm will be raised, which may be wrong behavior. However, the very fact that the policeman - right-handed holds the gun in his left hand is already suspicious.


A system integrated into the boots should track the change in gait. If a policeman suddenly limped, his walk changed dramatically, then this is a clear sign that something is wrong with the policeman. In the end, a policeman may get wounded in the leg and all the previously mentioned systems will not notice this.

Judging by the footnote at the bottom of the slide, the system with shoes remained at the idea stage and was not implemented. One can only assume that it was probably still at the design stage that implementation difficulties were found.

Custom Behavior Patterns

At the end of the presentation, there is a slide entitled “non-standard behavior patterns”. Unfortunately, there is a description of exactly one pattern: running. And indeed, it is difficult to argue with this, how long have you seen a policeman “quietly running about his business”?

The brain of this system currently serves as a regular smartphone. Special software receives data from all subsystems, searches for known patterns and, in case of a positive result, sends a message to the central server.

In the presentation, unfortunately, nothing is said about the method of transferring data from the subsystems to the smartphone. For example, if bluetooth is used, it is not clear how the problem of high-quality connection and data transfer guarantee, which plays a crucial role in this system, was solved.

It is also not clear why this project is closed and why it has become known only now, after the leak. At first glance, the project is nothing top secret.

The system will continue to work reliably enough when some subsystem fails, and in some cases even if several subsystems break down.

Currently, there are closed discussions on the topic, but is this system necessary for ordinary policemen? The main argument against its introduction is the cost and rarity of cases when a policeman comes under fire. In addition, while it is absolutely unclear how long this system can work on a single battery charge, because Some functions require quite serious computing power. It will be stupid if the batteries are not enough even for one shift of a police officer (on average, 12 hours).

Quite a different story when it comes to special police units. But in this case, the system should take into account that, perhaps, there is a serious exchange of fire involving a dozen people. It must correctly interpret all incoming information from all sensors, primarily from microphones and accelerometers ... With the right approach, this system can reliably determine the number and location of shooting criminals.

An important point that was provided for the development of this warning system is the fact that the purchase of new body armor and pistols is not required. In the existing armored vests injected layers. The weapon is not subject to alteration, the sensor in the gun shop does not affect its operation.

The whole system will work fully automatically. Thus, the policeman can focus on the situation and not be distracted by the thought that we should call for reinforcements.

The system becomes very logical if you think of it as a standard system from the world of Internet of Things. We have available a set of sensors that produce raw data. Some logical system filters them and draws certain conclusions based on known patterns. For example, a holster gives information on whether a gun is in it. The system of the next logical level analyzes data already from several sources and uses more complex patterns for analysis and can make more accurate and complex assumptions. For example, analyzing data from a holster, a tracker on a hand, in a pistol and microphones, allows us to conclude whether a shot was fired. The more sensors involved in the system, the more reliable it becomes and the more information it can provide.

It can be assumed that in the leaked presentation only central ideas are voiced, since a thought comes to mind, why not put a couple of sensors in a telescopic baton, in a flashlight or in a gas canister?


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