KJMTheEvolutionofForensics

= __The Evolution of Forensics__ =

__History of Forensics__

Forensic science dates back hundreds of years. Fingerprinting was one of the earliest forms of forensics, in China they used fingerprints to identify business documents. In 1892, a eugenicist named Sir Francis Galton made the first system for classifying fingerprints, this system is no longer used. In 1896 Sir Edward Henrey, commissioner of the Metropolitan Police of London, developed his system which is now used, it's based on the pattern, direction, flow and other characteristics in fingerprints. his system became the classification system used worldwide in around 1990's. Henry Goddard (Scotland Yard) became the first person to use physical evidence, and analysis to connect a bullet to the murder weapon, in 1835. This form of examination became more precise in the 1920's, when an American physician Calvin Goddard created the comparison microscope to help in identifying evidence. Later, in the 1970's a team of scientists at the Aerospace Corporation in California developed method of detecting gunshot residue (using electron microscopes). In 1836 a Scottish chemist named James Marsh conducted a chemical test, to see if you can solve crimes using blood as physical evidence. Almost a century later, in 1930, Karl Landsteiner won a Nobel Prize for classifying human blood into its various groups. Thanks to his work other scientists started to think of other ways of using body fluids to solve crimes. In the mid-1900's tests were developed to analyze saliva, semen and other fluids as well as making blood tests more precise. With so many new techniques emerging in the 20th century, people discovered that they needed a specialized team of investigators to analyze evidence found at crime scenes. Edmond Locard was a professor at the University of Lyons in 1910. In that year he set up the first police crime laboratory in France. For his work in forensic criminology, he became know as "the Sherlock Holmes of France". August Vollmer was the chief of Police in America, he established the first American crime laboratory in 1924, after the FBI (Federal Bureau of Investigators) was founded in 1908. At the end of the 20th century people started to say the criminals had no chance of escape. Forensic scientists had a lot of high-tech tools for analyzing evidence, some of these things are, polymerase chain reactions (PCR) for DNA analysis, digital fingerprinting techniques, and computer facial reconstruction.

__Fingerprinting__

A fingerprint is the impression of the ridges of a human finger. Prints are left by parts of your body such as fingers, palms, feet and toes. Ridges are raised portions of the epidermis on toes and fingers. On the palm of your hands and feet consist of more connected ridges. In many crime movies forensic scientists find smugged fingerprints on things like glass. They then carefully copy the fingerprint and find the killer. In real life fingerprinting is not that simple. Firstly the forensic scientist needs to locate the fingerprint, sometimes the fingerprints are invisible or very badly smugged. Fingerprinting has come a very long way since the time that police officers copied the fingerprints onto paper to the best of their ability. In the olden days forensic scientists could not search millions of criminal records, they had to study each fingerprint carefully and match prints together. Today, in Melbourne, the police can check millions of criminal records, match faces to prints, and see if the fingerprints that are found in the crime scene are already in the data base.

The Crime Scene

Crime scenes are discovered everywhere, and by many people. When the authorities are informed an officer arrives at the scene of the crime. The first thing the officer has to do is seal the area of, so no evidence is contaminated. Then they have to notify the senior investigator and (if necessary) alert the fire department and/or the ambulance. It is very important to write down the time of the arrival of the police, and other significant observations, so that the investigator in charge can evaluate what is of use, and what the next step should be. Whilst doing so the police officer can’t touch or tamper with any of the evidence. The officer must also write down the extant of the crime scene which means where the crime took place. For example, in the case of a murder there may be evidence not only where the crime was committed but also where the body was found or any other places that have a direct connection with the murder. The scene where the corpse was found may not be where the murder was committed; if so then the police need to know the mode of transport and the new location of the body. The movement of the body plays an significant part in the investigation.It is very important to seal off the crime scene, because the more people that visit, the more difficult it becomes for investigator. The area that is sealed of is the crime environment; the crime environment includes the entry and exit points, where the body was found, and where the crime took place. The crime environment is only accessible to the officials working on the crime. To stop evidence contamination personnel numbers are kept low. A log is kept of everyone who enters and exits the crime scene, this also includes arrival and departure times. There is also a separate log kept for the evidence, in this log you will find what evidence was moved from its original positions, who it was moved by, at what time, and where it is stored now. This is so evidence tampering is not an issue in court.

Suspects, Witnesses and Detectives

Suspects and witnesses are very important to a forensic investigator; they provide data that evidence cannot. The potential suspects and witnesses can be detained and question about the crime. The investigator can see if someone has been at the scene of the crime by taking samples of dirt and other things, such as plants and pollen, they then compare what they found at the crime to what they found on the suspects. The police have the right to search the suspect’s houses, if they to be find anything interesting they can store it away to be analysis. Witnesses can't talk to any other witnesses so they tell the police exactly what they saw, and not what they think they saw. Any suspect is innocent until proven guilty. Different detective are called to solve different crimes, they would have vast knowledge on a particular aspect of the crime, and only specializes in that aspect. A specialist is appointed by the senior investigator to investigate the crime. It is now the investigators job to find out who committed the crime, how it happened, and what evidence is there to prove that the suspect is guilty. Some common are burglary/theft, arson, murder, manslaughter, and kidnap.

Recording the Crime using Photography

The forensic photographer is one of the first people to arrive at the scene of the crime, they take photos of the evidence before it is stored and moved for its original position. Because the jury can't go to the scene of the crime photos are very helpful in showing the crime environment. Cameras capture the aftermath of a crime, this will later help in identifying the location of evidence. Close-up shots of evidence have precise requirements, such as the angle that it is taken at, the size of the object in the shot, the place that photograph has been taken at has to be said, the time the photo has been taken, and the clarity of the image has to be very good. If you use colour filters, adaptable light-guides, lamps and flood lights the image that you create will be of a high quality, and that can enhance the detail of the evidence. Ultraviolet light makes stains and fingerprints glow, violet lights makes gunshot residue and blood more visible, and blue and green lights are used to enhance fingerprints, to show fibers, and to make urine visible. This is all to do with the lights being reflected or absorbed.

Searching for Evidence

A crime scene can't be sealed off until the crime is solved, so the investigators have to work fast to collect all the relevant evidence. The longest they want to work to collect evidence is around two weeks, but searching for the relevant evidence is hard and takes time. Every crime scene is different, so they all require a different approach. Some crimes scatter evidence over a large area (car bomb), other crimes are confined to a small area (murder). Even though the crimes are very different they all have some general rules. The crime environment points out what area has to be searched first, an out-side area is searched before an inside area because the weather can cause damage to the evidence; also public areas are searched before private areas, because they have to be opened to the public. The investigators search for evidence before they look at the body, because they body can give precise evidence at any stage, where as physical evidence can be damaged easily.Methods of search are customized for the crime at hand. One method of searching for evidence is a 'line search' (used in searching for evidence in large areas). Investigators stand in a line and move forward, only looking for evidence in front of them. This is a very effective way of looking for clothing, hair, weapons, and human remains. Another method is the grid method. In a grid search two lines of people cross over an area from two sides. The way that they search will look like a grid. These methods are highly unpractical in builds, where room-by-room searches are used. Two people search in each room of a house for evidence, then they swap with another group, they swap around four times. This is a very useful way of searching for evidence, but this is really unpractical in big open areas.

__ Evidence Storage __

When evidence is gathered and recorded, it is packed and stored for analysis. Biodegradable evidence is stored in spirits so that the rotting process stops, while clothing and other artifacts are stored in seal able bags. The bags have to say the time the evidence was collected, by who, and where the evidence was before. All this has to be carefully done so that evidence tampering is not an issue in court. This is even more important when handling deoxyribonucleic acid (DNA).

__ The Autopsy (Forensic Pathology) __

An autopsy is the examination of the body after death, to find the cause of death (this may also be called a post-mortem ). It has been developed largely in Germany, and has been perfect over the years to make it more reliable. The autopsy creates a clear picture of the death scene. The autopsy is performed by a pathologist or a coroner, they reveal aspects of the crime such as the cause of death, the weapons used (if any), the time of death (exact to around thirty minutes). The autopsy plays crucial role in murder investigations in the field of forensic science. An autopsy is generally the most accurate method available to show the cause of death.

__Cause of Death__

The cause of death refers to why the death happened (blood loss etc.) it shouldn't be confused with how they were killed (stabbed, poisoned etc.). Te pathologists/coroners need to work out if the death was accidental, natural, suicide, or murder depending on the facts retrieved from the autopsy.One common cause of death is death from burns. When the investigators find a body at the scene of a fire, they firstly have to examine the breathing passage to see if there are any traces of soot inside, if there are it means that the person was alive during the fire, so the most likely cause of death would be from the fire. Next, blood samples are analyzed for the presence of carbon monoxide, cyanide or other poisons in the blood. These poisons are generally found in a body that has breathed in gases caused by burning synthetic materials (furniture, paint etc.). Forensic scientists look at the burns on the victim to see if he/she died from the fire. A body with burns with inflamed edges shows the scientists that the person died during the fire. If there are wounds or lacerations on the skin it would seem to have resulted from the fire, however, if signs of internal bleeding are present, it would conclude that the victim was already dead before the fire began.The second most common crime is hanging. If a person is discovered hanged or suspended in some way, the pathologists would have to find signs that the death was cause by the lack of oxygen. Some of the signs they look foe are bluish coloured skin, burst blood vessels in the eyes, and inflated lungs. The pathologist then looks for inflammation around the neck. If there are any signs of redness, swelling, tenderness, and heat the pathologist can concluded that the victim was alive while he/she was being hanged. If there is no inflammation they can conclude that the victim was dead before being hanged. The rope marks on the neck have to correspond to the rope found at crime scene, even the slightest difference between the two would imply that that, that rope was not the murder weapon. As a general rule most ropes make the shape of an upside-down 'v' on the neck, and the knot causes a normal 'V'. You can also identify other methods of the murder by examining the neck. Strangulation usually breaks the hyoid bone (it holds up the tongue) located in the neck under the jaw. This bone is rarely broken during hanging. In cases where strangulation is evident it could be cause by the lack of oxygen, or most likely as a result of the deliberate compression of the neck, cause the stimulation of the vagus nerve which causes the heart to stop. In causes were the hyoid bone is not broken, but where bruising is evident around the nose and mouth the death would be caused by smothering (they would have died due to the lack of oxygen). Bodies discovered in water have to be examined to see if water is present in the airways and stomach, and if the lungs have swollen up. Examination of the lungs can reveal if bleeding occurred, if it did it would suggest the victim struggled for breath. If things that flout are found in the victims hands it would show that he/she tried to save themselves (it would rule out suicide). However the death could have occurred from a heart attack. Sudden exposure to cold can (in some people) can cause a heart attack. Examining the larynx could prove this theory. To see if the body was dead upon entering the water an analyses of the diatoms is performed. Diatoms that are found in the water have to correspond with those found in the body.

__Time Since Death__

Police that arrive at the scene of the crime should be able to tell the how long the body has been dead for, just by measuring the body temperature of the victim, and the stiffness of his/her muscles. A more accurate evaluation has to be made by the forensic pathologists. The pathologists record the the inside temperature of the victim, the temperate at the crime scene, the weight of the victim, and other variables, which are then applied to a formula designed to predict the time since death. The core body temperature drops around 0.8 degrees every hour from the time of death, but can very depending on the variables (surrounding temperature, humidity levels, air movement, and fat levels in the body ). The corpse becomes stiff between thirty minutes and three hours after death. This process is called rigor mortis and occurs as the muscles in the body begin to stiffen from the lack of oxygen in the blood. Rigor mortis becomes apparent to the jaw and eyelids first, and then in the legs and arms. The stiffness slows if the highly is temperature is low at the crime scene. This method is highly unpractical after a long time.

The eyes of a victim are used to see how long the victim has been dead for. A cloudy film develops over the eyes within three hours after death. The eyes became softer because there is less fluid presser behind them. This isn't a common procedure, but it works well.

The colour of the corp se helps in finding out the time of death. 48 hours after death bacteria begins to breed on the skin, giving the skin a greenish tone. 4-7 days after death the skin begins to look marble like, and the veins come closer to the skin thus becoming more visible.

Forensic Entomology helps to see how long a person has been dead for. Three days after death Bluebottle flies and Syrphidea flies appear around the victims body. A week after death fly larvae and beetles come to the body. Between eight and eighteen days after death ants cockroaches, beetles and flies are present. After thirty days beetles, mites and flies are near the body. After two months no insects are present because, only bones remain.

The location of food in the victims digestive system provides important clues to the time of death of the victim. Chewed food will pass through the oesphagus and then down into the stomach within seconds of the initial swallowing. After three hours the food goes to the small intestine. Six hours after eating the food will be half way through the small intestine and beginning to move through the large intestine. If the victims small intestine is empty it suggests that the victim ate over eight hour ago. The full digestive process take a little over a day but can be effected by drugs, fear, liquid intake and sickness.

__ Death Manner __

Death manner means what type of death has happened (natural, accidental, suicide or homicide). Natural and accidental death occur more often then homicides and suicides. Natural deaths are those that are not cause by another human being. In this category you will see heart failure, disease, death from old age, etc. Autopsy show the death manner of the victim, how it took place, and when.

Homicide means the intentional killing of a person (murder). Some common examples of homicide are shooting, stabbing, smothering, strangling, hitting with a blunt object and burning.

The last death manner is suicide. Suicide is when you take your own life. Just like homicide it is illegal. To help someone commit suicide is also illegal.

__Using Plants to Solve Crimes (Forensic Botany)__

Forensic botanists look at plants on the suspects clothes, and on the victims body. These plants can provide valuable clues as to how the crime has happened. They can tell if the crime took place where the body was found, and if it wasn't then it can tell the forensic scientists were the crime happened. This is all to do with what is found on the victims body. If pollen from a near by garden is on the victim it could mean that he/she person has been there a short time before death. Sometimes this method is unreliable because wind can blow leaves, seeds, and pollen onto the victim. The most reliable way to see where someone has been is to check for these things on the sole of the shoe.

__Using Teeth to Solve Crimes (Forensic Odontology)__

Forensic odontologists or dentists can help solve crimes using their knowledge of teeth. If a apple is bitten the forensic odontologist can see the teeth marks in the apple, and make a solid model of the teeth. They get the dental records of the victim, and the suspects to see whose teeth match the marks found at the rime scene. Another way that the odontologists use their knowledge of teeth to solve crime is when a skull is found. The odontologist can work out what sex the person is, what height they are, how old they were, and the persons diet, just from looking at their teeth.

__Skeletal remains (Forensic anthropology)__

Forensic anthropology is a lot like forensic odontology but, forensic anthropology looks at all parts of the skeleton and not just the jaw and teeth. In cases where conventional techniques fail, and are unable to determine the identity of the remains forensic anthropologists are able to deduce certain things based on skeletal remains. Race, sex, age and stature can be found by looking at the remains and by measuring the bones.

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