Forensic Science definition of terms relating to ballistics. The purpose of rifling is to impart a spin on the bullet along its long axis, which gyroscopically stabilizes the projectile and allows it to travel more accurately. In rare occasions, identifiable and complete fingerprints may be discovered from the shell casings. The projectiles associated with shotshells may be round metal pellets (called birdshot or buckshot) or a single large lead projectile called a slug (which is the only correct usage of the word “slug” in Firearms Identification).Firearms can be divided into two main categories: handguns and long guns.Handguns are firearms that are designed to be fired using only one hand and can be further divided into two sub-categories: Revolvers and Pistols.A revolver is a handgun that is loaded using a revolving cylinder, typically with five to 9 chambers that can each be loaded with a cartridge. When a bullet travels down the barrel of a firearm, in addition to picking up the “macro” rifling marks (class characteristic), the bullet is also imparted with a pattern of lines and scratches from the individual characteristics in that barrel. courses that prepare you to earn For example, when a bullet is fired, the firing pin hits the primer on a casing, which ignites the gun powder inside of the casing, projecting the lead bullet down through the barrel. Forensic scientists in the Firearm and Toolmark Section practice firearms identification. Flashcards. New York Commission on Forensic Science Meeting.
the diameter of the bore of a firearm or the cartridge that it fires expressed in hundredths of an inch. Ammunition and firearms designed and/or marketed in Europe or other places where the metric system is used will reflect that in the caliber names, such as the 7.65mm Browning.Shotgun shells are specially designed ammunition to be fired in shotguns. How to use firearm in a sentence. Trace Evidence: Definition, Analysis & Examples College Biology: Help and Review Firearm definition is - a weapon from which a shot is discharged by gunpowder —usually used of small arms. The same kind of exclusion or elimination can be made if the rifling pattern has the same twist but different widths: wide lands and skinny grooves vs. wide grooves and skinny lands, for example.The class characteristics for a fired cartridge case include the cartridge caliber, the shape of the firing pin, and the tooling marks on the breech.If the class characteristics of two bullets or cartridge cases are the same, the firearm examiner moves on to the next level of comparison: individual characteristics.

Also called a weapon, gun, handgun, long gun, pistol, revolver, etc. Criminal Justice 306: Research Methods in Criminal Justice Key Concepts: Terms in this set (25) Caliber. Serves as a subject matter expert in the analysis of forensic evidence from criminal investigations of bombings and/or arsons in one or more specialized areas such as the identification of explosives residue, fire debris, or trace evidence (e.g., fibers, hair, soil, glass, etc. Let's say that while working in the homicide unit at the local police department, you're following up on a lead related to a shooting that occurred two days before at a gas station. The first three actions are found in weapons that fire a single shot.
Based on these class characteristics, General Jackson died as a result of “friendly fire”.The comparison of individual rifling marks using the comparison microscope evolved during the 1920’s, and received heightened attention when it was used by Lt.