Investigation Methods of Firearms

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.

Why do you think it is so important that all evidence be identified (such as marking the bullets and tagging firearms)? What consequences might result if these procedures were not followed?

Do you know what the steps are when it comes to processing firearms evidence? The first step to processing a firearm as evidence is to put gloves on your hands. Then you should take pictures of the gun when you find it at the crime scene. Make sure the picture is as clear as possible because it will be used in the court room. Make sure you included some form of measuring the gun that is in the picture. Next, take the bullets out of the gun and put the bullets in a line. Take a picture of it so the court can see the amount of bullets that was found at the crime scene in each gun. You also need to take pictures of all of the empty bullet shells that you may

Perfect example would be the 7.62x51mm vs. .308, both cartridges use a .304-.307 projectile. The .308 however, has a moderate charge and has less bore pressure associated with it. Unlike the 7.62x51mm which tend to run on the higher end of the spectrum, in terms of bore pressure. It’s important to identify whether your rifle is designated to .308 vs. 7.62x51mm. It can directly affect the longevity of the barrel, and if not checked it can be a detriment to the overall safety of the shooter. Having the ability to identify specific cartridges is a skillset that is dire. I’m going to cover the importance of being able to identify

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

The prosecutors firearm identification testimony for the case was poorly executed which allowed Waite to reexamine the bullets from the case and what he found was the rifling markings did not match up with the bullets that were test fired from Steielow’s gun. They determined that Stielow was not guilty due to the conclusion that his firearm was not used in the crime. Following this case Waite was inspired to develop a systematic process for documenting ballistics information to avoid making mistakes in later cases. After this Waite began to travel to different firearm manufacturers to document the process of creating the firearms to study the different characteristics in each.

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.

Self-contained metallic cartridges were first identified using a hyphenated system. Again there is no set way to identify cartridges and was voluntary and not every manufacture chose to follow it. Generally cartridges were hyphenated in two or three sets, such as .50=70, .45-70, and .30-40. The first number designated the projectile caliber, then the propellant charge in grains of powder. If there was a third number indicated it represented projectile weight in grams, such as .45-70-350. After the turn of the century the use of the hyphenated system changed and represented and different meaning. The U.S. Army switched their cartridge from the .30-40 Krag to the .30-03, representing .30 caliber and 1903 as the year it was introduced. With names it a whole different story, some represent the manufacture, designer or the user. .223 Remington, .44-40 Winchester, and .40 Smith& Wilson are some examples of manufacture names. For user it would be Police, Government, and NATO. Some manufactures even have catchy names for their ammo, for example Fireball, Express, Magnum or Nitro. There is a not a definitive rime or reason how cartridges are to be identified by, making it difficult to learn every variation of ammunition ever

Most of the crimes that are committed in our society involve a handgun. Gunshot wounds can be very challenging on determining whether or not it was a suicide attempt or homicide. There are some indicators that assist investigators reach a conclusion on gunshot wounds. One of the indicators is the location of the gunshot wound such as the entry and exit points. For example, as the bullet passes through the skin inward and can often travel through the body on a straight path. Furthermore, the damage to the tissue around a gunshot wound helps the investigators with the determining the distance the weapon was fired from (Swanson, Chamelin, Territo, & Taylor, 2012).

There is an estimated 300 million registered gun owners in the United States. With that many Americans owning guns, its not a surprise nearly 68% of all homicides reported to the FBI involved firearms. It’s a good thing the forensics of firearms has advanced to a point that with just a single round recovered, ballistic experts can tell investigators, what caliber round was fired what type of weapon fired the round, and in some cases the distance at which the round was fired. Without such advancement, more murderers would be walking free.

Goddard composed an article in 1925 titled “Forensic Ballistics”. This article explained the analysis of firearm evidence by using a comparison microscope. The comparison microscope

A rifle bullet is longer and skinnier, whereas a shotgun shell is shorter and thicker.By just looking at the two different types of ammunition, one may think that the shotgun shell is more powerful, but it actually depends on the caliber and the gauge. Caliber is what a rifle bullet is measured by, and shotgun shells are measured by gauges.The casing of a rifle bullet is made of brass because it is resistant to corrosion while the actual bullet inside of the cartridge is made of lead. Steel is sometimes used to make bullet cartridges too because it is less expensive than brass but it cannot be reused like brass can. Shotgun shells are constructedof a plastic hull with a brass heading. In the inside of the shot gun shell there is what is called wadding and shot. Wadding is material used to separate gunpowder from the shot, and shot are little balls made ofany number of metals, including lead, steel, bismuth, tin and zinc. When shooting a rifle, the cartridge only has a single bullet or projectile, but shooting a shotgun results in multiple shot pellets released from the hull and causes a pattern. Ranging several miles, a rifle bullet can travel more than 3000 feet per second when a shotgun only travels about 1100 feet per second. Maximum range for a shotgun is only a few hundred

The type of evidence that forensic ballistic evidence will usually be tied with firearms in some way and can be something as small as a bullet fragment or as large as hundreds of cartridges. Bullet

According to (“Investigations”, 2007) the first step to safely handling firearms found at a crime scene is to take pictures of the firearm. The second step is to take measurements and pictures of the firearm. The third step is to pick up the firearm while wearing gloves. The fourth step is to secure the firearm by turning on the safety, if there is one. The fifth step is to remove the ammunition, or bullets left in the firearm. The sixth step is to place the unused ammunition or bullets into a paper bag, label and seal the bag. The seventh step is to take the firearm and place it into a separate paper bag than the ammunition and bullets, and properly label and seal the paper bag. All used ammunition, bullets, and casings found should be placed

One way that it can be used is if bullets are left at a crime scene, they are taken to a laboratory to be examined for any evidence that would show enhanced clues about what happened. Same circumstance goes for gunshot residue, it can be found on victims’ hands as well as clothes. This determines if a person has recently handled or fired a gun. If you also have the shell of the bullet or bullet, you can figure out the manufacturer from the marking on them from the barrel of the gun (Firearms).