Most of us will have heard the term ballistics at some time or other-more often than not when we have been watching fictionalized accounts of police work on television or in the cinema. When you think of forensics you may think of something like “The Forensic Files”, “NCIS”, or even “Law and Order”. Although, ballistics is a part of forensics first we will look at forensics itself and how it came about. After getting the basics about the foundation in forensics we will look at ballistics and how the specifics of ballistics started, who is the founder as well as what ballistics consist of.
To the best of my ability, we will review different types of test preformed by a ballistic analyst. After gaining all of the knowledge of ballistics and forensics itself, we can then look at detailed steps in how to become a forensic ballistics analyst. Without question, the field of forensic science has come a very long way since its recorded beginnings in the 700s, when the Chinese used fingerprints to establish the identity of documents and clay sculptures. This field is one of the few areas of law enforcement where science, technology and crime-solving meet.
This combination supports the Theory of Transfer: “When two objects meet, some evidence of that meeting can later be found and verified. ” A few significant advances occurred in the years prior to 1800. In 1248, a book, Hsi DuanYu (the Washing Away of Wrongs) published by the Chinese, described how to distinguish drowning from strangulation. It was the first recorded application of medical knowledge to the solution of crime. In 1609, the first treatise on systematic document examination was published in France.
Then in 1784, one of the first documented uses of physical matching saw an Englishman convicted of murder based on the torn edge of a wad of newspaper in a pistol that matched a piece remaining in his pocket. Throughout the nineteenth century, many developments took place. Ballistics is the study of the functioning of firearms, the flight of the bullet and the effects of different types of ammunition. Ballistics in crime investigation was first formally established in 1923 when Charles Waite and Philip Garavell set up the Bureau of Forensic Ballistics (BFB). Later,
Colonel Calvin Goddar joined the team and together they developed their own specialized equipment. At the scene of a crime, police look for bullets and spent cartridge cases. When police find a suspect’s weapon, lab technicians take the gun and fire test bullets from the gun into a cotton wall or a water tank. Under a microscope, the technician can compare the striations on the test bullets with the marks on the bullet from the crime scene. He looks for the direction and degree of the twist, the depth of the grooves, and any imperfections. If the two bullets match, they are from the same gun.
Ballistic science can also be used to determine whether or not a person was present when a gun crime was committed. When a gun is fired, tiny specks of primer residue and gunpowder remain on the hand of the person who fired it. The police take residue samples from the suspect’s hands, and a lab analyzes the samples for traces of the chemicals antimony, barium, and lead. Ballistics is obviously a very important part of forensics science. Forensic science reflects multidisciplinary scientific approach to examining crime scenes and in examining evidence to be used in legal proceedings.
Forensic science techniques are also used to verify compliance with international treaties and resolutions regarding weapons production and use. Forensic science techniques incorporate techniques and principles of biology, chemistry, medicine, physics, computer science, geology, and psychology. Forensic science is the application of science to matters of law. Both defense and prosecuting attorneys sometimes use information gleaned by forensic scientists in attempting to prove the innocence or guilt of a person accused of a crime.
A basic principle of forensic science is that a criminal always brings something to the scene of a crime, and he or she always leaves something behind. The “some-thing” left behind is the evidence that detectives and criminalists (people who make use of science to solve crimes) look for. It might be fingerprints, footprints, tooth marks, blood, semen, hair, fibers, broken glass, a knife or gun, a bullet, or something less tangible such as the nature of the wounds or bruises left on the victim’s body, which might indicate the nature of the weapon or the method of assault.
Careful analysis of evidence left at the scene of a crime often can be used in establishing the guilt or innocence of someone on trial. In the past called forensic ballistics, this forensic science concerns itself with the comparison and identification of crime scene bullets and shell casing firing pin impressions with the marks on test-fired rounds in the crime lab. If the marks on the bullet made by the test gun barrel are identical to the striations (rifling scratches) on the crime scene bullet, or the firing pin impressions are the same, the crime scene weapon has been identified.
The science is grounded on the principal that no two guns will leave the same marks on the ammunition. Bullet striations and firing pin impressions are unique as a person’s fingerprints. Firearms identification also involves restoring filed off serial numbers, retracing projectile flights, identifying the various types of bullet wounds, and determining the range of close range shots through powder stain patterns on the target. Firearms identification experts apply the sciences of metallurgy, chemistry (gunshot residue analysis), microscopy, and ballistics. A knowledge of the gun smith trade is also useful.
Like document examiners, forensic firearms experts are trained on-the-job in crime laboratories. The term ballistics refers to the science of the travel of a projectile in flight. The flight path of a bullet includes: travel down the barrel, path through the air, and path through a target, the wounding potential of projectiles is a complex matter. Bullets fired from a rifle will have more energy than similar bullets fired from a handgun. More powder can also be used in rifle cartridges because the bullet chambers can be designed to withstand greater pressures (70,000 psi vs. 40,000 psi for handgun chamber).
Higher pressures require a bigger gun with more recoil that is slower to load and generates more heat that produces more wear on the metal. It is difficult in practice to measure the forces within a gun barrel, but the one easily measured parameter is the velocity with which the bullet exits the barrel (muzzle velocity) and this measurement will be used in examples below. Most guns have their own unique identifying features and even if the gun has not been left at the crime scene many degrees of information can be determined from the bullet, the nature of the wound and any residue that is left around it.
Bullets contain a mixture of gunpowder and cordite and these leave burn marks on the skin of the individual either wounded or killed, they also leave a fine residue on the fingers and hands of the individual firing the gun. These burn marks can signify closeness of the victim to the perpetrator, kind of weapon and also if the weapon has had any modifications made to it. Some weapons have been disarmed by having the firing pins and mechanisms removed but there are individuals who can ‘reactivate’ these weapons for use again.
Also, each weapon’s barrel contains small ligatures and grooves, which, when a bullet is fired from them, make marks on the shell casing, which can be used as a means of identifying the make and model of gun if these shell casings are found at the scene. It is also worth noting that an automatic-or semi automatic weapon-will expel shell casings as the weapon fires a round whereas a revolver will fire the round but retain the shell casing within the barrel. The controlled expansion of gases from burning gunpowder generates pressure (force/area).
The area here is the base of the bullet (equivalent to diameter of barrel) and is a constant. Therefore, the energy transmitted to the bullet (with a given mass) will depend upon mass times force times the time interval over which the force is applied. The last of these factors is a function of barrel length. Bullet travel through a gun barrel is characterized by increasing acceleration as the expanding gases push on it, but decreasing pressure in the barrel as the gas expands. Up to a point of diminishing pressure, the longer the barrel, the greater the acceleration of the bullet. Volgas, Stannard and Alonso, 2005) As the bullet traverses the barrel of the gun, some minor deformation occurs, called setback deformation. This results from minor (rarely major) imperfections or variations in rifling or tool marks. The effect upon the subsequent flight path of the bullet is usually insignificant. A handgun bullet must consistently penetrate a minimum of 12 inches of tissue in order to reliably penetrate vital organs within the human target regardless of the angle of impact or intervening obstacles such as arms, clothing, glass, etc. Penetration of 18 inches is even better.
Given minimum penetration, the only means of increasing wound effectiveness is to make the hole bigger. This increases the amount of vital tissue damaged, increases the chance of damaging vital tissue with a marginally placed shot, and increases the potential for quicker blood loss. This is important because, with the single exception of damaging the central nervous system, the only way to force incapacitation upon an unwilling adversary is to cause enough blood loss to starve the brain of its oxygen and/or drop blood pressure to zero. This takes time, and the faster hemorrhage can occur the better.
The FBI Ammunition Test Protocol is a series of practically oriented tests to measure a bullet’s ability to meet these performance standards. The result is an assessment of a bullet’s ability to inflict effective wounds after defeating various intervening obstacles commonly present in law enforcement shootings. The overall results of a test are thus indicative of that specific cartridge’s suitability for the wide range of conditions in which law enforcement officers engage in shootings. The test media used by the FBI to simulate living tissue is 10% Ballistic Gelatin (Kind & Knox 250-A), mixed by weight (i. . , one pound of gelatin to 9 pounds of water). The gelatin is stored at 4° Centigrade (39. 2° Fahrenheit) and shot within 20 minutes of being removed from the refrigerator. The temperature of the gelatin is critical, because penetration changes significantly with temperature. This specific gelatin mix was determined and calibrated by the U. S. Army Wound Ballistics Research Laboratory, Presidio of San Francisco, to produce the same penetration results as that obtained in actual living tissue. The 10 % gelatin has been correlated against the actual results of over 200 shooting incidents.
Each gelatin block is calibrated before use to insure its composition is within defined parameters. Copies of the test protocol are available upon request for those interested in duplication the testing or reviewing the procedures in greater detail. The gelatin blocks for handgun rounds are approximately six inches square and 16 inches long. As necessary, additional blocks are lined up in contact with each other to insure containment of the bullet’s total penetration. Each shot’s penetration is measured to the nearest 0. 25 inch. The projectile is recovered, weighed, and measured for expansion by averaging its greatest iameter with its smallest diameter. The Ammunition Test Protocol using this gelatin is composed of eight test events. In each test event, five shots are fired. A new gelatin block and new test materials are used for each individual shot. The complete test consists of firing 40 shots. Each test event is discussed below in order. All firing in these eight tests events is done with a typical service weapon representative of those used by law enforcement. The weapon used is fully described in each test report. First of all, you will need to have a good educational background.
Remember that ballistics is a science, and not simply a matter of guess work. Because of this, you will need to have a high school diploma, as well as advanced courses in ballistics. There are some colleges that offer courses and programs in ballistic studies, but in others there are none. At the very least, you need to study courses that are related to ballistics, such as chemistry, physics and other science fields. These will help you figure out the chemical elements that are given out when gun powder burns, and how to determine the impact that bullets make.
After you have finished your formal education in ballistics, the next step is to apply for an internship with a well known ballistics expert. At present, the number of ballistics experts in the country is still very low. But, most of these gun and bullet ballistic experts are willing to lend their hand in training other students. The best thing about working as an intern is that you get access to actual crime scenes, and you get to observe firsthand how a gun ballistics expert actually works. Eventually, the senior ballistics expert will allow you to conduct the investigation on your own, with only minimal supervision from the senior expert.
After getting the correct education and after passing your internship, you will be able to apply in police agencies as a ballistics expert. Networking is crucial if you want to be able to get a spot in the investigation crew as a ballistics expert. This means that during your internship years, you should already start getting to know the various officials that usually deal with crime scene investigations. This will give you the opportunity to publicize yourself and make it easier to apply later. If you really want to be a topnotch ballistics expert, however, it is also best if you study criminology and if you apply as a police officer first.
Doing this will allow you to understand how the justice system actually works, how law enforcers do their job, and it will give you insights on how crimes operate and what techniques and strategies are used in ensuring that a particular investigation is solved. A ballistics expert can earn up to $95,000 each year, depending on the level of expertise and experience that he has under his belt. In general, job opportunities for ballistics experts is not expected to grow much, because of the fact that most experts can process multiple cases at once, which means that hiring new experts is not always necessary.
If you are fascinated by guns and love science and using science to solve mysteries, consider becoming a ballistics expert. With these steps, you should be able to get started. After looking at the basics of forensic science itself, we now know where and how forensics came about. Ballistics is just a part of forensics in itself. Ballistics is simply just the study of anything that has to do with guns and ammunition. After we looked at the fundamentals of ballistics and forensics we then saw how the analyst tested the evidence presented from a crime scene.
Finally how to become a forensic ballistic analyst was then reviewed. With this information we are able to show how ballistics are important in the police work as well as determine if this would be a good career match for ourselves as a individual. After determining if this would be a exiting career choose, we know where to start in the process of becoming a ballistic analyst.
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