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Module Five: Text Questions
Review Questions 1. What is the NIBIN?
The NIBIN is a network that provides law enforcement agencies around the world with access to the images and information. 2. What is rifling? What two types of markings does this produce?
A rifling is a given spiral grooves by the manufacturer. This rifling or spiral grooves cut into the barrel of a gun in order to make a bullet spin as it is fired. Rifling produces grooves and lands. 3. What is a distance determination? How is this done?
A distance determination is the process of estimating the distance between where a shot is fired and its target. This is often done by looking at the patterns of powder
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It would be useful to know the distance between a gun fired and its target because if you know the distance you might be able to find more clues as to who did it by looking at where the shooter shoot the victim. 3. If you were in charge of retrieving bullets at a crime scene, what steps would you take to retrieve a bullet and take it to the crime lab?
If I were in charge of retrieving bullets at a crime scene I’d first I would have to find a way to remove the bullet out while preserving any possible markings on the bullet. Then the bullets can be placed into a marked container for identification purposes. Then to transport the bullet to the crime laboratory, I’d wrap the bullet in tissue paper and placed in an envelope or pillbox. I would have to be careful with the handling and packaging of the bullet, because I would have to be careful to preserve any trace evidence that might be present on the bullet. 4. What are some of the challenges in analyzing tool marks?
Some of the challenges in analyzing tool marks is it is difficult to duplicate the marks left by tools through tests in the laboratory and tool marks may not always give individual characteristics. 5. What is the Doppler Effect? How can the Doppler Effect be useful for a forensic investigation involving a shooting?
It is important for a forensic scientist to determine the distance from a gun to a shooter because in some cases a
Forensic ballistics and firearm investigation begin when the bullets, cartridges, a weapon, or any combination of the above found at a crime scene. With the evidence, a crime laboratory will explore for clues on some things that might cause a suspect or possible to prove that the things were used in the crime. By contrast, the markings on the bullets or cartridges found at the scene with those discharged from the suspect’s weapon, a ballistics expert will typically confirm if the rounds came from a similar weapon. Just the act of cycling a cartridge through the weapon without firing it will leave permanent scratches on the case that is distinctive to the weapon.
I would pick the handgun and ensure that it is not still loaded and if so I would unload the handgun and place the unused bullets in an envelope. The next thing that I would do is record all of the necessary serial numbers of the handgun, the make, model and caliber of the weapon. Then I would mark it in some form of inconspicuous manner for the lab. Then I would pick the shells with a pair of tweezers to make sure that I don’t mess up any finger prints that may still be on the shell. I would then place them in a separate envelope wrapped in paper or a box if I have one. Then I would label the evidence for transport to the lab.
I think the interesting thing about working with firearm evidence is learning about different types of weapons, identifying different markings on bullets and learning about the bullet trajectory and distance. The challenging part would be examining bullets that are broken or mutilated.
We found a 40 caliber at the house that matched the casings from the scene, we diagramed the location and the condition as well as photographed before recovering and securing. I examined to see if the weapon was loaded and it was not. I marked the position of the cylinder, using two pen marks I put on the top of the cylinder alone each side of the top strap of the frame. I noted the loaded casings found in the box of ammunition in the field notes. It was then bagged and sent to the lab.
When evidence is gathered, different equipment and processes are used to determinate what it means. In 2011, the Federal Bureau of Investigation estimated that 8,583 murder victims, in the United States, died because of a firearm. Forensic scientist can use equipment, such as the Integrated Ballistic Identification System, to find what firearm was used (Bureau). "They used a shotgun loaded with double-O buckshot. Inside the casing for each shot are nine
The victim sustained a gunshot to the abdomen and in the head. After analysing photographs of the crime scene and the bullet entries in the body, the investigators were able to determine the trajectory of the bullet’s path and discovered that for the gunshot to the abdomen the assailant was approximately 2 feet away. After being shot in the abdomen, the victim attempted to distance herself when she fell and the assailant came closer and shot her in the head. The two bullets were retrieved from the body so they could examine the bullet’s tool marks and they discovered that the bullets are a .38 caliber. The bullet’s lands and grooves will later be used to match the bullets to the assailant’s
In the event that any firearm is discovered at a crime scene there are certain steps that need to be done in order to properly collect any type of firearm evidence. If there is any kind of firearm found at the scene it should be rendered safe immediately. For safety is the first priority at any crime scene. Forensic technicians should assign an evidence number to the firearm, photograph orientation and close-up view’s, and take measurements of the firearm’s location prior to collecting it. In order to deem a semiautomatic pistol safe, the forensic technician should be wearing latex gloves an unload the weapon as follows; (Tina Young, 2011)
Firearm evidence is usually found and encountered in crime scenes against people. There could be many different circumstances like murder, homicide, assault, robbery, suicide just to name a few. So this is basically what firearm evidence
Let us start on how to collect and process expended projectiles and cartridge casings. When collecting expended casings, projectiles and remnants of shotgun ammunition each one should be numbered, photographed and measured for placement in a crime scene sketch (Tina Young, 2011). Each one collected should be placed in a pillbox or coin envelope then those should be placed into bigger envelopes or bags (Tina Young, 2011). If a projectile is stuck in a wall the section of the wall where the projectile is located should be removed (Tina Young, 2011). If a firearm found at a crime scene the best way to link it to the crime or other crimes is to test fire it into a water tank or ballistic gel. Once this has been done, the forensic tech can then compare the bullet and casing using a microscope. (Tina Young, 2011). If the firearm is not located then the casing or bullet can be ran through the National Ballistic Database. Now that we have talked about rendering firearms safe and also how they should be processed, now we can look at what information can be gained from the firearm and the cartridges and
When working with violent crime scenes, firearms are used quite frequently. The use of firearms can make the collection process much tedious. You have to remember safety first and treat all firearms as if they were loaded. There are many different types of firearms and ammunition out there, they all shoot different and not one firearm will create the same markings on the ammunition. Ballistics is the scientific study of the path of a bullet. A story can be told by the path the bullet takes. It can show where the shooter was standing, whether the shooter was inside or outside, and it can show whether the gunshot wound is self-inflicted or not.
It can tell the investigators with hand was holding the gun, but also reconstruct the position of the gun when it was fired. This again could help determine the how a crime was committed, but also with what weapon and by whom relating to angle of the gun. There was a study conducted by (S.N.Kunz et al 2013). Were looked into an apparent suicide, which had unusual characteristics for a suicide, which included an unusually blood spatter pattern on the man’s hands, it was determined by studying the crime scene photos and also the angle of the wound that the man did commit suicide, however, the unusual pattern was caused by an abnormal position of the gun and supporting hand. This can show that blood spatter analysis was needed to help determine the event.
“The combination of the trajectory analysis and the results of muzzle –to- target distance determination from gunshot residue patterns on the victims clothing (image 1) could prove key to
The weapon must be examined further for more evidence such as blood, hair, fibers, or paint that can be important. As the weapon is transported to a laboratory, it must be personally delivered. The loaded handgun must be transported in a specialized constructed box which has a means of securely holding the firearm and has a metal plate blocking the muzzle. If the firearm is to be sent by mail it must be unloaded and securely packaged (Lofland, 2013).
According to Young and Ortmeier (2011), the forensic value of firearm and ballistics evidence is associated with the ability to link the firearm to the crime and the shooter. Markings and striations of the firearm on expended cartridge casings and projectile discovered at a crime are collected and compared to known bullets in a database of known firearm types and test-fired bullets. By checking these national databases, the firearm can be linked to several crimes or not connected to any crimes whatsoever. However, other evidence such as DNA and fingerprints can be linked to other crimes and therefore can link the person to the crime as well (Ortmeier, 2011).
Have you ever wondered hot snipers are able to make long distance shots? Or how crime lads can determine the exact gun used in a crime? Well those both involve ballistics. The actual technical definition of ballistics if the science or study of the motion of projectiles, as bullets, shells, or bombs. (“Ballistics”). The origins of ballistics can be traced back to the 15th century when a german gunmaker discovered barrel rifling.(Evans 27). In order to understand ballistics and its effect on modern crime labs you need to understand interior and exterior ballistics, which treats of the motion of a projectile while it is still in the gun and considers the motion of the projectile from the time it emerges from the gun until it reaches the target; Newton's Laws of motions, and the coriolis effect.