 until 20th century there was nothing so special about this picture. It was just one of the many hours when you saw pictures in museum. So what made it so famous? The one of the most famous pictures in the world. Answer symbol. It's criminal. Let's start from the beginning. According to a worldwide brief, more than a half of released prisoners become recidivists. What does it mean? It means if somewhere the crime was committed. Most probably it was committed by a previously convicted person. But why is it so special and important to identify criminals? For this we have a few reasons. First one, it would be easy just to prove his guilt in accord. Second one, for recidivists the guilt should be more strict. And the last one, if the case is already voted for prison in this crime. Mutilation and human braiding. It was a normal practice of criminal identification for thousands of years. The things got worse, the health cut off, the heretics lost their tongues. So in the 19th century, in the beginning of the 19th century, the practice of mutilation almost completely disappeared from Europe. In that time the success of investigation completely relied upon the talent and experience given to him. So one of the most experienced was Warns-Wabidog. It was the first director of crime detection police in France and a criminal. He personally could recognize more than a thousand criminals in Paris. And in 1825 he came up with an idea just to set a special index card for each prison person. So it included the habits of how the war is criminal and his portrait. It was so simple. It was systematized by the name of the medical order. So simple and effective, but just for a short period of time. From 11 to 27 March, a series of explosions happened in Paris. So it affected the House of Prosecutors and judges who worked on the case against other cases. In that time police found out what the bomber was someone who called himself Francois Rouchard. They printed the description of his appearance in newspapers and tried to find this card with this guy, someone who looks like from the previous convicted person. However, in 1892 there was more than 5 million index cards. And since the only way to find and identify criminals was by the name, surprise, criminals don't always tell you real names. So it was impossible. Then, that's just a few thousand of index cards. It's possible to check all of them and to identify a person. But if it's more than 5 million, it never works. So in that time, French police left a huge cabinet filled with index cards just turned out to be useless. But there was one phenomenon. And you have to solve this problem. It was Alphonse Bertrand. He started his career in 1879 as a pilot player and all day long he just filled these cards with descriptions. The same description of it completely different but people just drove him crazy. It was a description like middle-height, normal face, non-distinction marks, something that could fit any of us. So it was quite useless. And he proposed to use 11 measurements identification system. He thought it would be unlikely for any two person to share their sizes or different body parts. So, for example, like height, armspan, trunk. And he made some measurements in last and dead prison a few months later. He came out with that different people could share different sizes and different parts of bodies. But 4 on 5 or 6 measurements simultaneous never happened. So, how to systematize? He just took the first parameter, its height, put it from the lowest shortest one to the highest one and split it in 3 equal groups to the short, middle and high. Then he took the next parameter and in this each group split it in 3 parts. So, for example, you have 270,000 index cards of criminals. We just split them in 3 groups. Each one is 90,000. When we take the next parameter, its armspan, split it in 3 groups, now 30,000. The next parameter, trunk, etc., etc., in the end after 11 measurements, it's going to be just a few files in one folder. In that time, there was no simple system for mugshots. Mugshot is a picture of a person made for police records. So, he standardized it as well. Every Merthelon card included one profile picture and one full face picture. It was breakthrough in criminal justice. Really an idea, but it was one problem. He was awful speaker. None of the authorities could understand his explanations and none of them wanted to implement it. So, he failed. But he continued to work on this system. Back to Paris, 1882. François-Arabachon was caught in one of the restaurants in Paris and the hell, Merthelon, turned out what François-Arabachon, in reality, it was Königstein, who was wanted criminal, whom Merthelon measured in prison like 2 or 3 years ago. Only after this case, Merthelon, our code was recognized and implemented in France and then all around in New York and the world as well. However, even this system was far from ideal. 22 August 1911. Somebody knows what it is. One of these was stolen from the local. So, this case was investigated by Merthelon. In that time, there were no records, at all no records for any restores or photographers who just took pictures from museums to work with them. So, even the authorities in the loop, they understood what the picture was stolen only in two days. So, the criminal could be anyone. The only trace when it was found, it was a fingerprints on the frame. In that time, these index cards were already included fingerprints of the criminals. However, the whole system was systematized by anthropometric measurements. So, it was completely impossible to find the same fingerprints out of millions of cards. Investigation had went nowhere. It would be funny because in that time the detectives to be or fingerprints systematization already existed and it worked in almost all around the world except one country, you know, which one. Go back. Bengal, India, 1992. A general inspector of police in Bengal at the Henry. He tried to teach Indian officers to make proper and accurate measurements for burden of guards system. However, he failed. Lack of education among officers caused a lot of failures and a lot of mistakes. So, it was useless. He tried to find a simpler way to identify criminals and he found it. Inspired by the articles and difficult articles that every popularity drawing is unique for every person, he found a way how to systematize it. So, every fingerprint could be divided into three groups. Ever it's loops, ever arts, ever rules. So, how to understand which one is what. We have in loops only one delta. Delta is a triangle area where we just radiate in pretty different directions. Words have two of them, here, for example, and arts have none of them. If you have a lot of new fingers, almost most of you, you have loops 60% of all fingerprints. It's loops a little bit less than words and arts. No, it's interesting. It takes some time. But it's better to do it in the box because it takes some time. Since there are only 5% of people, you line them with words in one group and just to transfer this data to the married one. So, for example, for loops and arts, you give a zero, for more, it's one. And then we have a special heteroscopic formula, which looks like this. There's LPF. It's variable for left pinky finger, for left ring finger, middle finger, et cetera, and the same for right hand. So, if we just put a variable, depending on which probability drawing we have in this formula, we will have some numbers. So, for example, here, the probability drawings of these hands. So, W is for loops, L is loops, A is arts. So, in this formula, if our left pinky finger is small, so we just put one here. Here's a loop, loop, loop, loop, loop for four hours. So, here is zero. And the same for the right hand. Here, the middle finger is normal, so we put one here. And in the end, we have the folder with the name 70, up or 6. So, we just put this criminal with these finger prints in the folder which names 70, up or 6. The maximum what it could be is 32 in the numerator. It means what all finger prints are both. And the minimum could be one. It means what all the other numbers are both parts. So, we have 32 different options for left hand, 32 for right hand, and we have 1024 different folders. It was a way out of the system analysis in that one. This spectroscopic system was firstly implemented in India. Three years later, in British Empire and all around the world, except one country. Yeah, it was France. The normal reason why? The French didn't want to use British invention. Okay. Second December, 1914, police got somebody to try to sell one of these authentic variant. His finger prints both were seen as finger prints on the frame. So, they found his index card in Bertiland's system and it turned out to be a recidivist invented in chance of perugia. And they had his finger prints in that card. So, the crime of the century could be solved in two hours instead of two years. It was a shame for Bertiland that both France and in few months they implemented the telescope in France as well. What about Mona Lisa? Mona Lisa went missing for two years. All this time the press called in the most significant picture in the world. They just invented a fun fiction about it. They speculated on her smile. In the end, just the failure of French police made such fame for Mona Lisa, but it's still bringing millions and millions of tourists to the world. Thank you.