Forensic Science Text Questions

Forensic Science Text Questions 1. If you found a firearm at a crime scene, what steps would you take in order to transport the weapon to the lab? The first concern in collecting firearm evidence is always safety. So I would pick up the gun by the trigger guard or the checkered portion of the grip and put on gloves to unload the gun to carefully to preserve evidence such as fingerprints and gunpowder residue and also so it doesn’t accidentally discharge on the way to the lab. Then I would put an identification tag and attach to it to the trigger guard. The tag would include information about the case number, the firearm’s serial number, and my initials. 2. Why do you think it might be useful to know the distance between a gun fired and its target? It is useful to know the distance between a gun fired and its target because when a gun is shot, traces of gunpowder travel out of the barrel of the gun with the bullet in the direction that the bullet is traveling. If the end of the gun barrel, or muzzle, is close to the target, some of this gunpowder residue will be transferred to the target. The pattern or distribution of the residue helps forensic scientists estimate the distance of the gun from the target. In situations where an individual has been shot, it may be helpful for investigators to know how far away the shooter was from the victim. For example, in some cases a defendant accused of murder may say that the shooting happened in self-defense. The actual distance between the two individuals may indicate whether the defendant is telling the truth. Similarly, knowing the approximate distance of a shot can help forensic scientists determine if a death was a suicide, or if it was a homicide made to look like a suicide. 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 would wrap the bullet in tissue paper and place it in an envelope or pillbox. In handling and packaging the bullet, I would be careful to preserve any trace evidence that might be present, such as paint or fibers. 4. What are some of the challenges in analyzing tool marks? A cast of the impression using silicone rubber or filled plastics is often made of the impression. If a suspicious tool is found at the crime scene, investigators may be tempted to put it into the actual tool mark to see if it fits. This should not be done, however, since it can alter the original tool mark. It is often difficult to replicate crime scene tool marks through tests in the laboratory, and it’s not hard to see why. In order to produce the exact same markings, the tool must be used at the exact angle and pressure as the tool was used at the crime scene. 5. Why is gunshot residue important for a forensic scientist? What are the potential complications with this type of evidence? When a gun is fired, gunpowder not only goes in the direction of the bullet but also travels back toward the shooter of the gun. Gunpowder residue may be found on the hands or body of someone who has recently shot a gun. This residue can help investigators learn whether a suspect has recently fired a gun or not. The residue is most likely to show up on the thumb web and on the back of the hand, but the residue can be distributed to other areas of the hands and arms as the gun is handled or other activities are performed. If a shooting took place, investigators also collect the victim’s clothing for analysis. The clothing can give investigators important information about the distance between the gun and victim, as well as other trace evidence. Clothing should be removed as carefully as possible to avoid tearing the garment or disrupting gunpowder residue. Each item of clothing should be placed in its own paper bag. Any wet clothing should be air-dried out of the sun and then placed in a paper bag. When a gunshot is part of a crime scene, forensic scientists examine clothing and other objects from the scene for gunpowder residue. Some gunpowder residue may be visible to the naked eye, but other residue may only show up under infrared photography. Gunshot residue on the hands can be difficult to find, even with modern forensic techniques. Part of the reason for this is that the residue doesn’t last for long on hands, particularly if the shooter washes, wipes, or rubs their hands. Studies indicate that even within hours of a shooting, it can be very difficult to find gunpowder residue on the hands of a shooter.