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... he greatest crime investigator in history relied on the only true witnessevidenceto solve a crime. Although fictitious, Sherlock Holmes techniques of acute observation and logical application of detail underlay the basis of solving any crime. Those skills, added to todays growing technology allow police efforts to successfully conduct an investigation. Since evidence is stable and will not change its story once in front of the jury, or forget what it saw, those who collect, analyze and interpret the crime scene play very important role. Forensic science is science applied to answering legal questions.
Under the rules of forensics, evidence is broken down into four categories: TESTIMONY statements from witnesses under oath DIRECT EVIDENCEeyewitnesss accounts CIRCUMSTANTIAL EVIDENCE information that may disprove or prove a point REAL/PHYSICAL EVIDENCE any tangible article etc. (fingerprints, weapons, blood) It is the accumulation of all the above evidence types that weigh down the case at hand. Physical evidence is attained through forensic analysis and is most useful in cases involving homicide or foul play. When the call comes into the dispatcher at the police department, notifying the police that there may be a murder, an officer arrives on the scene to preserve the crime scene and control the situation until the Homicidal unit arrives. Once the expert detectives arrive, there is an assessment of tiny details to large details that were noted about the crime scene. Examples of the more obvious noted details are like whether or not the lights are on, or if the doors are open or closed, and location of furniture as well as body.
The rest of the process is handled by various individuals with a certain area of specialty. Once of the most crucial facts to determine is time of death. Along with witness accounts and such, postmortem (after-death) changes are the most accurate Because of the known fact that when we breathe, oxygen comes into lungs and is circulated through our system by passage of blood cells. Since every system shuts down up on death, bacteria begin to manifest and let out enzymes that produce gas by breaking down the body from the inside.
Consequently, the shade of blood significantly darkens and due to the force gravity, it sinks to the lower sides of the body as muscles begin to tense up. Within a half-hour after death, lividity occurs. Lividity is evident when the part of the body facing the ground turns purplish in color. In the early stages, if the skin is pressed, it will temporarily turn white under pressure. Whiteness is not possible more than five hours after death. By the four-hour mark, the body is usually completely stiff; a process called rigor mortis, which begins with smaller muscles.
Two to three days later, the muscles return to a relaxed state since the fibers have begun to deteriorate. Also taken into account for time of death is the behavior of insects if the murder took place outdoors or in an area with bugs. The division of this particular science is called forensic entomology. The scent of death attracts insects as naturally as it repels humans.
A basic rule of thumb for entomology follows these time allotments: (Forensic Science by Andrea Campbell. ) 10 minutes after death if in open air, flies lay 1000 s of eggs in mouth, eyes, etc. 12 hours Eggs hatch and maggots begin to eat tissues 24 - 36 hours after Dry skin is consumed by beetles 48 hours later Spiders etc. begin to eat the bugs that are eating the body A criminologist named Edmond Locard developed a theory in 1910 and it is referred to as the Edmond Locard theory. This theory states that every time something comes in contact with another, it takes or leaves a part of itself or another. (The Missed Evidence, by Dwayne S. Hildebrand. ) It is also referred to as theoretical exchange when pertaining to homicidal incidents. There are many types of evidence that fall under that theory. Body fluids are the most important, such as blood, semen, urine, saliva and sweat.
With a certain DNA analysis, then blood and seminal fluids can be traced to an individual and be very accurate in doing so. If not, it can at least be determined from what certain population group it belongs to. The manner in which blood or other body fluids should be obtained is with caution and sterile materials. Tape can lift a stain off and all pieces of evidence should be stored separately. This process is usually taken under by crime scene technicians.
In order to preserve any physical evidence, the hands of the corpse are bagged. This prevents anything from contaminating or altering whatever may be under the fingernails or on the skin. Hair samples can tell only if it is human, which race, location of growth on body and how it was removed. Whenever there is a death due to violence, unexpected, sudden or suspicious circumstances, the body is handed over to the coroner. The autopsy, the examining of the body, includes only examining the crime scene, but identifying the body, examining external areas of the body, dissection and internal analysis, as well as examination of the body fluids for drug or alcohol presence. (Campbell) In cases where the body is damaged beyond recognition, the deceased's identity is up to the work of forensic anthropologists.
These scientists study the remains of the corpse for clues about the death as well as clues about their life. By looking at the bones, it is possible to tell if the subject was male or female. Noting the ossification, or bone formation, the anthropologist can narrow down the age range. Height and weight, as well as determining which hand was dominant is possible by measuring bones and muscle attachments. Skull dimensions and nose measurements can help figure out the race of the body. Sometimes at crime scenes where a shooting occurs, bullets and casings will be found in the surrounding area.
Under examination at the crime lab, the make and model of the weapon can be determined. This is especially helpful if there are already suspects. The same thing goes for tool marks. The experts in this field of forensic ballistics have used methods dating all the way back to 1835 in London. (Campbell) Because of the high speed that the bullet shoots down the barrel of a gun with, the spiral pattern on the barrel are engraved into the bullet.
These spirals are called striations. Just like fingerprints and just like pennies, there are no identical barrels. Also in the case in which the gun is found at the scene, but no obvious clues as to the owner, there is another technique that aids ballistic experts. If the gun goes off in the vicinity of anything soft, like hair or clothing, fragments from these articles are sucked up like a vacuum into the barrel. One such instance where this wonder pulled through for investigators was in Florida.
There was double-homicide in which the murderer had shot the gun through pillows to prevent a loud bang. Other clues led them to one particular suspect, but what nailed him were the bits of feathers found in the barrel of his gun. On many television shows and movies, it is common to see the prosecution or detectives argue that traces of barium and antimony were found on a suspects hand. These are two metals that come from the gun and thanks to the gunshot residue test, it is easy to just stroke cotton swabs with nitric acid on the webbing between the thumb and trigger finger. It has been found though, that the presence of the chemicals does not necessarily prove that the person fired the gun, but the absence of them may prove they did not. Other objects that serve as clues are so minute, they require a microscope to find them.
Yet small things can be huge in the world of evidence. Take fibers for instance. They are so easily transferred to another person via any sort of contact. Being analyzed can lead to evidence that perhaps paves the way in finding out where a victim was held, what the killer was wearing, or clue the police in on the method of transportation used. In the case of the Atlanta child murders o f 1979 to 1981, fibers played a significant role. Greenish-yellow carpet fibers and a different fiber that was violet in color were found on many of the bodies.
The FBI traced the carpet ones and found out that that exact color had only been available for a year. The agents began to get a list of all the buyers of the carpet, during the time in which the killer changed his pattern. In order to wash away any particles, he began to throw the bodies into the river. The Atlanta task force began to keep a constant eye on the river and sure enough, when a man was witnessed dumping something into the river one night, police were able to get a warrant issued. They found matching green and violet fibers in the home of arrested suspect Wayne Williams. He could only be linked beyond a reasonable doubt to two of the thirty victims, but was sentenced to life in prison.
And believe it or not, dirt does serve a purpose. A forensic geologist can pinpoint where dirt on either a suspect or victims shoes or whatever came from. This bit of skill was used in the case of the Coors murder that took place in Colorado. It began in 1961 when Adolph Coors III, beer company executive, had been kidnapped.
Although his car was found seven months before his body was, through intense analysis, the investigators collected their clues. There had been a number one suspect, so when his car was located in New Jersey dump, it was at first disappointing to find that everything on the inside had been burned. But unfortunately for the killer, soil samples from under the fender matched with the kind found in the Rocky Mountains and some more that was just like the dirt from Coors grave. This bit of evidence weighed heavily on the prosecution side and both charges of kidnapping and murder were filed against the suspect. The most common and obvious physical evidence that is left behind are the fingerprints. They leave a lasting impression wherever they touch literally.
Every finger on every single person has a unique print. The friction ridges form pattern like swirls and lines. Since underneath the top layer of skin are sweat glands, secretion of this kind cause any oils or dirt to stick to whatever is touched. And this is not a modern technique. In fact, all the way back in the fourteenth century, Persians required fingerprints on every government document. Since then, the study of finger prints, called Dactyloscopy, has made a huge impact in legal proceedings because they can unmistakably identify convicts.
Before the bright idea of having the fingerprints of anyone arrested on file, policemen were required to memorize the faces of convicts. It was not until 1879 that someone actually used their thinking cap as well as human observation. Alphonse Bertillon theorized that measurements of the bony parts on ones body could be used as identification purposes. This system was utilized until the early 1900 s.
But when a convict found another person that looked almost exactly like him, with the same Bertillon measurements as well as name, there was the need for a more solid way. With the help of studies from men like Edward Henry, a system was worked out. A national fingerprint bureau was established in 1924. (forbear. nyinforsbar. nvm) But before it was all put together, a case occurred in New York City in 1911. A man by the name of Caesar Cella was accused of burglary.
Since there were no witnesses and five people that claimed an alibi for Cella, the prosecution looked high and low for means to bring Cella down. A detective had found several dirty fingerprints along the window sill. From the words of the detective, the marks matched Cella identically. But the judge as well as the defense did not think they should buy the detectives story over that of the five alibi providers. So an experiment was run. The detective was sent out of the room and fifteen random people made finger markings on a piece of glass.
One of them also had to make a print on the desk of the judge. The judge then requested that the detective figure out which print of the 15 was also on the desk. Using a microscope and five minutes of time, her matched the print. This was the first documented case in which fingerprints were used as evidence. Expert examiners begin looking for fingerprints at the exit and entry locations. Anything in the are that may have been used, moved or touched is examined.
Fingerprints can be left on surfaces that are rather soft such as gum, fresh paint, tar, cooking ingredients, powders etc. The more obvious types of fingerprints are those that have been touching blood, grease or oils. They usually are highly visible. Of course then there are the toughies the invisible prints that are left on surfaces such as paper or other smooth areas. With the help of a dusting kit, these invisible prints soon become apparent to the eye. The dusting technique is done by simply brushing a light powder over the desired area.
Then a clear tape lifts the print off the object and it is placed on an index card. More complex ways to lift prints are by using chemicals and lasers. But just because a print is found, the search is nowhere near over. No leads, no suspect means no big deal. Other imprints that can be vital in building a case are ones from the bottoms of shoes or from tires on a car. There has been much progress over the course of the years.
More and more high-tech equipment provides quicker and more efficient methods of interpreting the crime scene. These are devices that Sherlock Holmes never would have dreamt about. Yet solving a crime comes right down to the investigators involved. Unsolved cases from long ago have been finally labeled closed after a new method was able to result in fresh evidence.
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Research essay sample on Time Of Death Sherlock Holmes
