firstgroupfive

Brittneys Powerpoint:

Codys Space: I am going to do five slides on bullet entrance holes.

Bullet entrance holes typically have very even margins. Almost all non-contact bullet entrance holes will be smaller in diameter than the bullet due to the elasticity of the fabric. Some firmer materials and larger caliber bullets with large hollow point cavities may cause bullet entrance holes to be closer to the actual bullet's diameter but in most cases the diameter of the bullet entrance hole will be of little help in determining the caliber of the bullet. Contact or near contact entrance holes and entrance holes caused by a bullet that has struck an intermediate object will typically have very uneven margins. Contact entrance holes will typically show extreme damage to the material of a garment. Generally speaking, the higher the velocity of the cartridge the greater the damage to the garment in a contact gunshot. When a bullet strikes an intermediate target (for example the victim's arm) before entering the victim's shirt it may cause the bullet to fragment, expand, or even tumble. The resulting secondary bullet entrance hole can be very irregular in shape and hard to visibly distinguish from an exit hole. Subsequent testing for gunshot residues usually help in making this type of determination. Bullets that strike a target at an extreme angle will usually leave an elongated hole. These holes typically will still have fairly even margins. It's not too uncommon for a grazing bullet to cause several holes in a wrinkled or folded garment. A common characteristic of bullet entrance holes is the presence of bullet wipe residue. Not always apparent on darker colored materials, bullet wipe residue is a darkened ring around the immediate margins of the hole. This ring of residue is caused by lead being wiped from the surface of the bullet as it passes through the material. Lead bullets normally leave the heaviest deposits of bullet wipe residue but it is not unusual for jacketed bullets to also deposit bullet wipe residue. Lead fouling in the barrel and lead primer residues can be on the surface of a jacketed bullet. Chemically processing a garment for lead residues will cause a pink reaction around the hole.



Brittney: i am going to get information on bullet comparison

Adria: am going to get some information on bullet exit wounds. weapons of the same calibre distinct gunshot residues should be expected at the exit Exit wounds Most bullets are made to not exit. Alot of times exit wounds will be present. This might be because the use of a projectile is more powerful than necessary. It also may be due to the projectile striking an area (such as an extremity) with minimal tissue. Exit wounds are almost always larger than entrance wounds, because of the fact that the bullet has expanded or tumbled on its axis. Pieces of the bullet might produce secondary missiles The bullet path may be altered by striking bone or other firm tissues, such that the bullet track may not be linear Exit wounds may not appear directly opposite entrance wounds. The victim may have been shot while standing or sitting, but when the body examined at an autopsy, it is lying down, so that soft tissues may shift position. wound.

jones: types of bullets