Crime Scene Investigation, Part 1

An Essay By Jackie West // 6/11/2012

(This is the research paper I wrote for my freshman year of high school, and while some may find the content dull, it gives me something worthwhile to put on apricotpie.) Millions of crimes are committed every year, and not all of them are solved. But crime scene investigators and scientists are here to make the world a better place. Using ordinary things like blood, dirt, and glass, and also technology superior to what the earliest crime investigators have, they are able to solve many crimes. Without them working to help arrest and convict criminals, the number of unsolved crimes would probably spike. The crime scene is where evidence is found and could be where the crime was committed or planned, or where a criminal hides out. An area becomes a crime scene when a body or other evidence of a crime is discovered. The ‘golden hour’ of a crime scene investigation is the time after the crime when the evidence is freshest. This is when it should be gathered. Unfortunately, witnesses can all too easily ruin evidence at crime scenes, so when the area is roped off and declared a crime scene, a path through it and the evidence there is carefully made so as not to disturb anything. An outline of the area is drawn, and chalk is used to draw outlines of any bodies that may be found there to help determine things about the crime. Investigators wear special clean suits with hoods mouth masks to keep anything like cells and hairs from contaminating evidence. Those involved in working at the crime scene range from emergency workers to profilers. Emergency workers are the police officers who set up the crime scene and make arrests. The crime scene investigator is in charge of everything at the crime scene, from evidence to other scientists-everything except for bodies. The C.S.I . finds, photographs, and collects evidence. Crime scene technicians store the evidence safely in sealed and labeled bags to be taken to the crime lab for investigation. If there are any bodies present, they are checked by the medical examiner. The profiler studies everything present at the crime scene in an attempt to figure out the reason(s) behind the criminals’ behavior and thinking. In the 1800’s, crime scenes were documented using photography which, even today, is important in capturing important clues and recording items left at the crime scene. To catch every aspect of a piece of evidence, photographers document the crime scene and evidence before it is touched. Documentation of the crime scene is absolutely essential. The names and descriptions of the suspects and witnesses are written down and their fingerprints are taken. A diagram of the crime scene is drawn and detailed notes about everything-from evidence to people present-are carefully written down. Thorough investigation is crucial to make sure nothing is missed. The observation of the crime scene and its evidence is cautiously planned; team experts in this part of the investigation, called ‘scene-of-crime officers’ or ‘SOCO’s, are brought in. Observation is imperative-criminals always leave some kind of clue behind, in the form of fingerprints, hairs, and dead cells, among other things. This evidence is not supposed to be touched yet. The entrance and exit made by the criminal are determined. The clues left by the criminal help the crime scene technicians figure out how the crime occurred. They use special tools, like tweezers, rulers and tape, to collect evidence carefully so as not to damage it, and also to measure it. Evidence can show that a crime really occurred because sometimes what looks like a crime may have been an accident. It can also help identify an unknown body, show what happened at a crime scene, help with the creation of a crime timeline, rule out innocent suspects, and prove information provided by suspects and witnesses true or false. A thorough search has to be made for evidence. Things like foot impressions, paint, dirt, seeds, broken glass, tire prints, and carpet/clothing/furniture fibers can all be crucial evidence. Things that look like they are out of place at the crime scene could be pieces of evidence. The smaller pieces of evidence are collected before the larger pieces are, and all evidence is marked with special numbered papers so they can later be referred to. Criminals will do anything to make sure evidence isn’t found-hiding bodies, for example, or throwing away crucial evidence-and they sometimes plant evidence to possibly evade accusations and arrests. Assumptions are forbidden; the observing has to be done without forming definite conclusions. Everything from blood to cars can be used to find and arrest criminals. Tooth marks can be matched to the bites of suspects and this can be very helpful because everyone has a different bite. DNA matches can also connect criminals with crimes; all you need are some finger, toe, lip, and/or palm prints that have blood, sweat, or oil present. Latent fingerprints-invisible ones-can be lifted off surfaces with special dusting powder and tape or found with lasers. A unique substance called cyanoacrylate can be heated, and its matter evaporated, so that the vapor sticks to fingerprints. ‘Visible prints’ are stained by things, and ‘plastic prints’ leave impressions in substances such as food or glue. Broken fingernails’ lines can be microscopically matched to criminals to the fingernail of a suspect and betray them completely. Also, bodily secretions, such as sweat or saliva, can be DNA tested in order to find a match in a criminal/suspect. Shoe prints found in snow, mud, sand, and other substances are measured, photographed, and sketched. Compared with the shoe prints of criminals and suspects, matches can lead to an arrest as can matching dirty shoeprints to criminals wearing the same kind of dirty shoes. Shoes can be dirtied by certain marks and stains, like oil, dirt, or blood. Everyone also has a different gait. What substance made the footprints and the gait of a criminal can be used against suspects. Aluminum foil can be shocked with 15,000 volts of electricity to make ‘latent shoeprints’ stick to it. No two people have the same fingerprints, footprints, and palm prints. Everyone has different DNA. There are special markers in millions of spots on DNA strands that make a person stand out from others. DNA tests on prints can be matched to the DNA of suspects and witnesses.


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