DNA analysis and frequently used emojis: what evidence do modern criminologists collect?

There is no one hundred percent proof that would accurately point to the criminal. And the facts in any criminal case should not contradict each other. Criminologist Evgenia Kryukova told blogger Boris Vedensky about these and other important details of the investigators’ work. Record their conversation posted on YouTube channel THE BASIS, and Lifehacker made a summary of it.

Fingerprints

Every person has unique patterns on all of their fingers and toes. These combinations are created by papillary lines. They come in three types and differ in direction and shape. Lines form combinations that, according to criminologists around the world, are never repeated. True, there is no single database of such patterns, so there is no absolute guarantee that there have never been and never will be people with the same patterns on the planet. But the probability of such a coincidence is considered minimal.

Therefore, the main thing for the investigator is to get a complete fingerprint. Then it will be possible to say exactly what kind of person left it. If a specialist has only half of the pattern, it is more difficult to identify the owner. There is a possibility that you can confuse similar pictures and make a mistake when identifying someone.

It is also important to remember: if fingerprints of a specific person are found at a crime scene, this does not prove his guilt. Let's say someone robbed apartment. During the inspection, investigators found “fingers” and determined who they belonged to. But a person can say that he was once a guest in this house. Or he worked together with the owner and therefore touched some of his things.

But if it is clearly proven that these people did not know each other and, in principle, could not have met, then the fingerprint can serve as evidence of the accused’s involvement in the crime. After all, the accused somehow had to penetrate to the apartment. And if a person could not do it legally, then there is a possibility that he is the criminal. At the same time, the found trace cannot be the only evidence of guilt.

DNA analysis

For this study, traces of blood, sweat, semen, and saliva are usually taken. In almost any criminal case where there are victims and biological materials of suspects can be obtained, analysis DNA used to identify the criminal.

Random coincidences are impossible here. The method is excellent, but the problem is that you need to have a sufficient amount of material for analysis. After all, research is carried out many times in order to obtain the same result, which no one will doubt.

Therefore, if a person left a drop blood, then it can be identified. If you just leaned against the wall and stood there for a while, no. And if his forehead was pressed against the glass and a large imprint remained, the chances of doing an analysis and finding this person are greater, although they are not one hundred percent. In a violent crime, all such traces are very important.

Handwriting

Today we know for sure that there are unique signs that can be detected when handwriting analysis. This is the pressure force and spelling options for various characters. Each person will have their own unique starting and ending line, as well as the angle of writing, when they write a letter.

Of course, the letters do not always turn out equally smooth and neat. There is such a thing as handwriting variation. People press the pen differently when they are in a hurry, tired, or trying to change their handwriting. And also in a situation where they are simply not able to hold their hand confidently.

Therefore, before analysis, specialists try to find out under what circumstances the written this or that document and even what position the person was in at that time. Sometimes this information helps clarify the circumstances of the incident that are important for the investigation.

Handwriting science has been developing for a long time, since the 19th century. And today specialists use techniques developed over centuries and take into account modern realities.

Digital handwriting

Nowadays, in addition to the usual, forensic scientists also analyze digital handwriting - that is, the features of working with the keyboard and mouse, the choice of buttons, and the force of pressing. And errorsthat a person regularly does.

For example, a suspect often misses and instead of one letter presses the next one. This is an individual indicator that characterizes a specific person. And if he types a message on a new phone or tablet, he usually makes more inaccuracies than on a familiar device. And these errors are different.

For example, he had never put before a comma instead of a period, and now I’ve done it several times in a row. Or suddenly he started adding extra spaces. This means that a person rarely works with a specific gadget or even picked it up for the first time.

Another important marker is the emojis he uses. For example, criminals may use some of them as code signals when corresponding. And if in the dialogue of the suspects the same symbols appear more often than others, it is worth paying attention to this. And analyze whether this is an ordinary conversation or criminal correspondence.

Bonus: polygraph readings

If we talk about modern technologies, it’s hard not to remember polygraph. But for now his testimony is not considered evidence. After all, the same person can react to the same questions in completely different ways. It depends on his mood, well-being, and attitude towards the verification procedure. If he is nervous, the polygraph readings will differ from those taken in a calm state.

But the methods of working with this tool are also being improved. Today, sensors are connected to different parts of the body. The polygraph records 15–20 parameters: breathing, pulse, various micro movements.

First, the device records the primary reactions. Then the person answers several questions - neutral, pleasant and unpleasant. Sensors record which parts of the body begin to move, which muscles contract, and how breathing changes. Then other questions are gradually added - those that interest the investigator.

Perhaps, after connecting neural networks to the device, the work of the polygraph will become even more accurate. And his testimony will be accepted as evidence. And maybe this will happen over the next few years.