Fingerprints.

Finger fingerprint files are coded according to the natural order of fingers, which is suitable for the identification of ex-criminals, alias criminals and nameless bodies. Single finger fingerprint files are coded and filed according to the thumb, food, middle finger, ring finger and little finger of the right and left hands, which is suitable for fingerprint identification at the crime scene. Palmprint files are classified and coded according to the patterns of the three major areas of the palm, which is suitable for on-site palmprint recognition.

Because fingertips are sensitive, they have the most chances to contact with objects, and the regular pattern on the surface of the finger ball is easy to identify, dactylography focuses on the texture structure of fingerprints.

There is an area called triangle in the middle of the fingerprint, which consists of a central stripe, a peripheral stripe and a baseline. Fingerprints are divided into three types according to the central pattern and the shape of triangle: bow type, basket type and bucket type. According to the shape of the central pattern, it can be divided into ten categories. The basis of fingerprint classification is: ① the pattern and shape of the center line. ② The number of mastoid lines between the center point and the triangle point. ③ The triangle traces the end of the line.

Symbols obtained by fingerprint classification are arranged into analytical expressions for personal identification. The number of fingerprints depends on the number of fingerprint cards. In the case of the same type, personal identification is carried out according to the details.

Some countries have developed and tried a new retrieval and identification technology, which uses computers to digitize fingerprint patterns. Some principles are that the scanner scans the fingerprint image, and the reflected light spots are recorded by the electronic recorder. The difference of light spots can indicate the direction and branch of the ridge. Some principles are that the feature points in the fingerprint image are automatically classified and coded into the memory, and compared with the original fingerprint coded data, so as to carry out personal identification.

Before fingerprints were used for personal identification, people used many methods in slave society and feudal society, such as breaking hands, cutting ears and tattooing faces as criminal marks. The invention of photography has created conditions for face recognition, but cosmetic surgery has become an effective means to deal with photographic recognition. 1879, French anthropologist A. Betillon invented anthropometry, which is a combination of anthropometry, feature description and photography. It flourished for a period of time, but it still could not accurately identify individuals, and was finally replaced by fingerprint recognition. China is recognized as the birthplace of fingerprint application. There is a record of "six strokes" in the Qin bamboo slips of Sleeping Tiger Land. According to the existing historical data, the use of handprints began in the Tang Dynasty. 1959 Tibetan contract unearthed in Milan, Xinjiang, with four red handprints printed on it. Suleiman, an Arab businessman who first introduced the application of handprints in China, recorded that he pressed handprints on IOUs when he introduced the customs of the Tang Dynasty in Travel Relations magazine. Since17th century, western countries have made great progress in fingerprint research by using modern science and technology. Modern fingerprint technology was introduced into China in the early 20th century. Because colonialism divided the sphere of influence in China, different fingerprint classification systems were adopted by local police organs during the Republic of China. After the establishment of People's Republic of China (PRC), the fingerprint classification system in China was unified 1956.

The science of studying the physiological characteristics and texture structure of palmar dermatoglyphics and the principles and methods of its collection, appearance, storage, classification and recognition. Fingerprint is an important basis for personal identification in criminal investigation; Fingerprint is an important part of criminal technology (see trace inspection). Because fingertips are sensitive, they have the most chances to contact with objects, and the regular pattern on the surface of the finger ball is easy to identify, dactylography focuses on the texture structure of fingerprints.

There is an area called triangle in the middle of the fingerprint, which consists of a central stripe, a peripheral stripe and a baseline. Fingerprints can be divided into bow, basket and bucket according to the central pattern and triangle shape. According to the shape of the central pattern, they can be divided into ten types. Fingerprint classification is based on patterns and midline forms. The number of mastoid lines between the center point and the triangle point. The end of the triangle route.

Symbols obtained by fingerprint classification are arranged into analytical expressions for personal identification. The number of fingerprints depends on the number of fingerprint cards. Too fine fingerprint classification is difficult to retrieve. Computers have been used to replace manual retrieval. In the case of the same type, personal identification is carried out according to the details. Fingerprints are divided into three basic categories: sweat latent fingerprints. Visible fingerprints and stereoscopic fingerprints. So far, the most common is the latent fingerprint of sweat, which is generally invisible to the naked eye. They are formed by sweat, either from fingers or because fingers unconsciously come into contact with sebaceous glands in the face, fingers and body. Even if a criminal wipes and dries his hands thoroughly, if he puts his hands on his face or hair, he is likely to leave fingerprints at the contact place, especially on glass balls or smooth wood.

Various methods can be used to process or extract sweat latent fingerprints for inspection. The most common method is to use gray powder or black powder. In the past, it was a mixture of mercury and white jade, but now, it more consciously reduces the physical danger of users. ) It is difficult to extract from permeable samples, such as paper and cardboard. It is best to smoke with iodine. Iodine can react with grease in sweat, or it can react with Han Sanming. Triketones can react with amino acids in sweat.

The second fingerprint is the easiest to identify. Because there are fingerprints left by blood, ink or other similar methods on your fingers. But it's hard to find at a crime scene. The third kind of fingerprint is three-dimensional fingerprint, which is formed on soft surfaces such as cheese, soap or putty.

The retention time of sweat latent fingerprints is variable and is mainly controlled by many factors. If you put it on a hard protected surface, it will stay there almost forever without touching it. Sweat latent fingerprints were found and extracted from the objects in the ancient tomb. How to show fingerprints: Finding fingerprints requires patience and experience. Because fingerprints are small and usually colorless, it is difficult to find them without careful observation; Fingerprints left by clean hands on smooth objects are harder to find. Different cases make it easy to leave fingerprints in different places. At the scene of theft by sliding doors and picking locks, the places where fingerprints are most likely to be left are doors and windows, boxes, drawers and safes. At the scene of a murder case, we must first check the perpetrator's tools. If there are tableware on site, check boxes, tableware and cups. Fingerprints can be found by magnifying glass under natural light; For colorless fingerprints with smooth surface, the illumination angle should be 30 degrees with the help of light, which can overcome the interference of reflected light and is not difficult to find after repeated observation. Fingerprints on transparent objects, such as glass plates, can be checked by light transmission.

To extract colorless fingerprints, we must first make them appear, and then extract and identify them. There are many ways to display fingerprints, and the common and simple methods are as follows.

Powder development method: choose metal or nonmetal powder with great color contrast with the surface of the object, and use the characteristics of low adhesion of fingerprints to change colorless fingerprints into color fingerprints with additional layers. The operation method is to dip a little powder with a soft brush, flick the handle of the brush to make the powder evenly dispersed on the fingerprint, then shake off the excess powder with a pen tip or gently brush it off, and the colorless fingerprint can be turned into a colored handprint. Commonly used powders include aluminum powder, iron powder, copper powder and graphite powder. The particle size should be about 500 mesh. You can also use a magnetic fingerprint brush, made of permanent magnets, and iron powder or powder containing iron ore powder. In the process of operation, the powder is evenly coated on the fingerprint, and then the excess powder is sucked off with a magnetic fingerprint brush. The advantage is that it can avoid the bad influence of the brush on the fingerprint details. The magnetism of permanent magnets should not be too large, and a certain distance should be kept when absorbing magnetic powder.

Fumigation method: dye the fingerprint of colorless sweat to achieve the purpose of appearance. The substance used is iodine vapor. Iodine is a nonmetallic element, which is black-purple crystal and can be sublimated at room temperature. The operation method is to put paper, plastic, etc. Pour the suspected fingerprint into a jar with iodine, and after a certain period of time, a clear purple-red fingerprint will appear. It can also be heated to promote the rapid sublimation of iodine tablets. The solution is to heat the bottom of the bottle slightly with an alcohol lamp. The disadvantage is that fingerprints will not be preserved for a long time at room temperature, and iodine will sublimate again. The remedy is to fix it in time by taking photos, starch film method or palladium chloride solution method.

Silver nitrate method: more than 98% of substances in sweat are water, and 1.5% are various organic or inorganic substances, including sodium chloride. Silver nitrate reacts with sodium chloride and decomposes into silver ions after illumination, thus showing gray-black fingerprints. The operation method is to lightly coat the fingerprint with silver nitrate solution with the concentration of 1%-5% with a brush or cotton ball, expose it in the sun or light, and fix it after the fingerprint appears. The fingerprints that appear are sealed with black paper to avoid blackening due to overexposure. Silver nitrate method is particularly effective for old colorless sweat fingerprints on light-colored paper and natural bamboo products. It is better to prepare silver nitrate solution with anhydrous ethanol instead of distilled water. Adding a small amount of aminopyrine to the solution can quickly develop fingerprints without exposure.

8- hydroxyquinoline method: the substance is white or yellowish crystalline powder with low boiling point. After heating and sublimation, it can combine with more than 30 metal cations such as sodium, potassium and calcium in sweat to generate various fluorescent substances. Under the irradiation of short-wave ultraviolet with the wavelength of 2537 angstroms, it can produce light blue fluorescence and show fingerprints. This method is suitable for self-fluorescent polystyrene plastic, white-gray walls and sweaty handprints on paper.

Laser irradiation method: The trace substances in colorless fingerprints can be fluoresced by laser irradiation on the surface of substances, which has a good effect on colorless fingerprints on paper, glass, wood, plastics, textiles and metal receptors.

Colored fingerprints found on the spot can be fixed and extracted according to specific conditions.

Extracting articles with fingerprints is conducive to the proper preservation of original physical evidence and traces; It is convenient for better research and extraction under laboratory conditions. For color fingerprints on large and bulky objects, if possible, separate and peel them off.

Photographic extraction: This is one of the commonly used methods. First, it will not damage fingerprints and their receptors; Second, it can objectively and truly reflect the relationship between the fingerprint receptor and the surrounding environment and other objects. It is appropriate to shoot a single fingerprint with the original fingerprint size.

For those fingerprints that cannot be extracted from the original, they can also be extracted with tape paper. The operation method is as follows: after adding a layer on the colorless fingerprint by powder method, stick it on the fingerprint with a flat transparent adhesive tape, pay attention to pressing it to prevent wrinkling and foaming, then carefully lift the adhesive tape from one end and stick it on a piece of paper with a contrasting color with the fingerprint, and it is finished. For white ash, smoke black and other colored superimposed fingerprints, paste method can also be used to extract and fix them.

You can also use gypsum powder, silicone rubber and other methods to take out and fix the three-dimensional fingerprint mold.

Computer fingerprint identification: a new retrieval and identification technology that uses computers to digitize fingerprint graphics has been developed and tried in some countries. For example, the "Finder System" of the US Federal Bureau of Investigation, whose principle is that a scanner scans a fingerprint image, and the reflected light spot is recorded by an electronic recorder. The difference of light spots can indicate the direction and branch of ridges; The principle of Rockwell fingerprint identification system in the United States is to extract feature points from fingerprint images and automatically classify them into a memory, and compare them with the original fingerprint coded data; Japan is in 1982. After the fingerprint image is processed, the fingerprint center line is extracted, the center coordinates are established, and then the feature points are automatically coded and identified. Before fingerprints were used for personal identification, people used many methods in slave society and feudal society, such as breaking hands, cutting ears and tattooing faces as criminal marks. The invention of photography has created conditions for face recognition, but cosmetic surgery has become an effective means to deal with photographic recognition. 1879, French anthropologist A. Betillon invented anthropometry, which is a combination of anthropometry, feature description and photography. It flourished for a period of time, but it still could not accurately identify individuals, and was finally replaced by fingerprint recognition.

Application of fingerprints

Case 1: Francesca Rogers

Time: 1892

Venue: Nicochia, Argentina

Significance: Everyone who is convicted of fingerprint evidence can clearly see the same ending as this tragic girl who was murdered for love.

Nicochia, a small town on the Atlantic coast of Argentina, is located 250 kilometers south of Buenos Aires. At first glance, it doesn't look like an important position in the history of criminology. 1892, it was here, in a small house on the outskirts of this city, that two people were killed at the same time. This case still resonates today. The victims were two illegitimate children of a 26-year-old woman named Francesca Rogers.

/kloc-On the night of June, 0/9, Francesca ran into the neighbor's cabin with tears in her eyes and said bitterly that Winners Quiz had killed her child. Neighbors all know that Winners Quetz works on a nearby farm. She used to be Francesca's passionate suitor, but she didn't succeed. The neighbor took her son to the police station and ran into Francesca's cabin to find the two children. A six-year-old boy and a four-year-old girl. He died of multiple head injuries, and no weapons were found at the scene.

The sheriff spent little time examining the crime scene. He wants to know more about Winners Kratos. Francesca sobbed and said that Wenas Quez was a middle-aged man and a complete idiot. He was madly in love with her, but she once scornfully refused to associate with him further. That afternoon, the retarded farm worker made more demands than before. Finally, she faltered and promised to develop a relationship with another young man. Sonasquez was angry. Insult and abuse, and threaten revenge. Then he rushed out. Francesca came back from work that night and found the front door wide open. When she approached, Wenas Kautz ran out of the toilet. In his panic, he almost knocked her to the ground. In the bedroom, she found two children dead.

Canas Quez was detained that night, and Wenas Chaz admitted that he had threatened Francesca, but took no action. Even the beating didn't change Wenas Quez's insistence on his innocence. Repeatedly frustrated, the police took more extreme measures. He tied Wenas Quanzi up and put him next to the brightly lit bodies of two children all night, hoping that remorse and fear of retribution would let him go.

The next morning, Nass remained unwavering, and the next week tortured his conscience and prevented him from telling the truth. The sheriff hesitated. Did he arrest the wrong person? This feeling rises and falls. Anyway, the sheriff started looking for another suspect. At this time, there have been rumors about Francesca and her young lover, and someone overheard that she was getting married. At the same time, the sheriff's doubts began to shift. His investigation skills were first-class, and there was almost no time to waste. He decided to shake Francesca and make her nervous breakdown. He stayed outside her hut all night, shaking the windows and doors, making some sharp and strange noises, and then imitating Lurgi in The Avengers. But Francesca was one step ahead of him and ignored it. When she went to work in the morning, her consciousness was not damaged at all. To make matters worse, she ignored the police chief's haunted behavior at night and still insisted that canas Kratos was the murderer.

Ask for help

At this juncture, the sheriff began to seek assistance from the police headquarters in La Plata. This opportunity is hard to come by. The head of the General Appraisal Bureau is an immigrant from Dharmachin named June Vasiti, who knew the benefits of fingerprint identification earlier than most people. 189 1 in September, he clearly put forward the classification of ten fingers by using the basic materials of garton. But so far, he has been confined to some prisoners in the local prison. But Vashtic has been looking forward to expanding its application scope. When he sent Jarva Reitz, a senior police officer, to investigate Nicochia's murderer, he didn't know that he would make a new history.

Jarva Reitz was shocked by the extremely limited level of the local police station. He immediately realized that Wenas Kratos had no time to kill people, and his alibi was absolutely reliable. But this poor man, limited by his own intelligence, ignored this key problem. Francesca's young lover was also exempted from the guilt of the same crime, so Jia Varese guessed that Francesca was the only suspect. ...

Without any great certainty, he went to the hut where the crime happened to look for clues. After several hours of searching in vain, he found a brown mark on the bedroom door, which suddenly became obvious in the moonlight. After careful investigation, it was found that this was the mark left by a bloody thumb. Jarva Reitz took a saw, sawed off the door, and then went back to the police station and ordered Francesca to be taken into the police station. He pressed her right thumb into the printing box and printed her fingerprint on a piece of paper. Relatively speaking, Jarva Reitz's eyes are not old enough, but when he studied this fingerprint under a magnifying glass, he found that the bloody fingerprint on the door matched Francesca's fingerprint.

Mastering the fingerprint evidence, Francesca's original iron will collapsed. She admitted that she killed two children because they deprived her of the opportunity to marry that young man. She stoned them to death and then threw the stone into the well. Then wash your hands carefully, but she never thought that she touched the bedroom door for an instant.

Francesca Rogers was convicted and sentenced to life imprisonment, thus confirming her position in the history of crime.

conclusion

For June Vasiti, successfully solving the case in Nicochia is a brilliant victory. When he wrote a letter to a friend, he said, "I can hardly believe that my theory has proved to be valuable." Now I have a trump card, but I hope I will have more soon. "He is too confident. Disappointingly, the official attitude towards fingerprints is hostile and distrustful. Vashtic did not lose heart and continued to fight for it. By 19 16, he really succeeded in establishing a national fingerprint registry, and it is expected that everyone's fingerprints will be registered. But the plan proved to be hopeless and unpopular. Riots and domestic opposition eventually led the government to abandon the plan and destroy the existing login. 1925, June Vashtic died. Some people say that he died of delusional depression.

Case 2: Stroshen Brothers Company

Time: 1905

Venue: London, UK

Significance: Although Britain admitted fingerprint evidence in the trial of 1902, it was not until this appalling murder that this new technology made headlines.

For more than twenty years, Thomas Farrow and his wife, Ann, have run a paint shop in Desenford, south London. The old couple are very popular among the neighbors, and their schedules are very regular. What is puzzling is that on the morning of March 27th, 1905, the store did not open as usual, and other employees could not enter. The reason for this abnormality will soon be clear. In the living room, Mr. Farrow was killed by a club. The wife upstairs is lying on the bed in a pool of blood, naked, but still alive. She was also severely beaten. Four days later, Ann passed out and died.

As we all know, every Monday morning, Farrow gives Chapman a week's profit, so there is no doubt that robbery is the motive. An empty safe with receiving trays scattered on the floor. There is also a mask modified with black stockings on the bedroom floor. There are two similar masks downstairs, indicating that there is more than one intruder. The Scottish Fingerprint Institute checked the safe and the inbox. They found that the fingerprints on the inbox were not left by any victim or the police present (one of them admitted touching the inbox). These fingerprints are also different from the more than 8,000 fingerprints registered in Scotland.

The milkman Henry Xinlin and his young assistant found two people leaving the paint shop at 7 15 on the morning of the murder. They described one of the tall men, wearing a blue wool serge coat and bowler hat, walking in a panic. His partner is wearing a brown coat. Hat and brown boots. According to these descriptions, the neighbors chatted and named two people-Albert Stroshen and Alfred Stroshen. Both brothers have criminal records of theft, and both have seen two people at the crime scene. When Albert's landlord was summoned by the police, he recalled that Albert had asked her if she had any old-fashioned stockings for him, but she answeredno. Later, on the bed she rented to the tenant, she found a mask made of stockings hidden between the mattresses.

Alfred's mistress Hannah clementi provided more detailed evidence. She has no intention of helping her grumpy lover. She blinked her melancholy eyes and revealed that he had gone out on the night of the murder. The next day, he threw away his coat and put black shoe polish on his worn brown shoes.

Two brothers were captured.

One Sunday a week later, the police thoroughly searched the places frequented by the two brothers and arrested Alfred in a public place. He claimed that his brother went to the seaside and his brother Albert stayed nearby the next day. The two of them were taken to tauerbridge police station. Sheriff Charles Tomlins is one of the founders of the Scottish Fingerprint Institute established in 190 1. He extracted the fingerprints of two brothers with a color box. He compared the fingerprints of each finger with those on the inbox. I found that the fingerprints on the inbox were strikingly similar to Alfred's right thumb. Therefore, the two brothers were charged with murder.

In the trial, the prosecution, headed by Richard Moore, suffered a serious setback. Neither milkman recognized the defendant as the man they saw leaving the paint shop. The whole burden of this case falls on fingerprint evidence. With the help of enlarged photos, Collins proved that Alfred's thumb was strikingly similar to the mark left in the inbox in twelve places. The most important thing is that there is no absolute contradiction. The jury was very impressed and showed great interest in Collins' theory. They all wanted to find out the technology of fingerprint extraction, and one of them volunteered to print his fingerprint.

Obviously, the defendant does not think that fingerprint identification is a foolproof technical method. When arguing about this issue, they recommended Dr. John Garsin to come forward. After a fierce personal attack on Collins, the doctor went on to state the classification of fingerprints and thought that the thumb print on the safe did not belong to Alfred Stroshen. Just then, Moore found two letters, written by Garcin that day, and submitted them to both the prosecution and the defense, expressing his willingness to testify. The jury's reaction to this opportunist was naturally ridicule. They think that Garcin's intention to cheat is quite obvious. The judge also stressed that thumb fingerprint evidence should be cautious, but admitted that they were indeed strikingly similar. Garcin's suggestion is for the jury. I wonder how much weight there is in the movement. To be sure, the jury still found Stroshen guilty of murder.

conclusion

Garcin's career was disillusioned. Since then, medical professors have paid little attention to fingerprints. Fingerprint has gradually become a field with only trained experts. Drink beer. For the Rochen brothers, their contempt for modern forensic medicine is unwise. Modern investigative science outlives both of them. The two brothers were hanged on May 23rd, 905 on/kloc-0.

Case 3: Thomas Jennings

Time: 19 10 year

Location: Chicago, Illinois

Significance: This case led to the adoption of fingerprint evidence for the first time in the murder trial in the United States, thus creating a new history of forensic medicine.

Clarence Hiller lives on the second floor of Chicago West 104 Street with his wife and four children. 191September19 in the early morning, Mrs. Hiller found that the gas lamp near their daughter Florence's bedroom went out. At this time, the gas lamp should have been on. She woke up her husband, anxious to know the truth.

He met a stranger during the inspection. There was a fight and both of them fell on the stairs. After a while, Mrs. Shearer heard two shots, and then heard her husband's faint cry for help. Then the front door slammed shut. Mrs shiller found her husband's body on the stairs.

Neighbor Jayne pickens heard gunshots and women crying, and came at once. It happened that his son Oliver had been talking to the policeman Floyd beardsley not far away. The two of them rushed over as soon as they heard the gunshots. Beardsley was told that the gangster lit a match and ran into Shearer's daughter's bedroom. Clerici, the eldest daughter, is fourteen, and Florence, the youngest daughter, is one year younger than her. Neither girl was attacked, but they were too scared to ask for help. After a while, the deadly battle began.

There are some fine sand and gravel under Florence's bed. There are always three unused warheads next to Florence's body. This seems to be the only clue. Beardsley didn't know that the murderer was only detained for other reasons.

Less than a kilometer away from Shearer's residence, four off-duty policemen found a man running around in the dark, always furtively looking behind him, as if afraid of being followed. He emptied his pockets and found a.38 caliber pistol. He claimed his name was Thomas Jennings. There was blood on his clothes and his left arm was injured. Asked why, he said that he fell off the bus earlier that night.

The police were not moved by his story, but sent him to the police station. We just got the news that Shearer was murdered. Soon, the injured man became the prime suspect. In particular, I learned that this man was released a month before serving his sentence for theft. Doubts slowly focused on him. Only two weeks after his release, he broke his parole oath and bought a.38 caliber pistol under an alias. The bullets found in the search are the same as those near Clarence Shearer.