Ballistic Trajectory Lab and Notes - PowerPoint Presentation

Slide1

Ballistic Trajectory Lab and NotesSlide2

Crime Scene A: a shot was fired at the white vehicle parked across from the target store. The car is parked 75 ft from the store. A shot was believed to have been fired from the roof of the store. The store is 40 ft tall. Is it possible for the shot to come from the roof of the building? Explain your answer.Slide3

Crime Scene B: A 5.5 ft man was walking in downtown Austin. The man is shot in the knee while heading toward the frost building. The man was 85 ft from the building. What floor was the shot most likely fired from. Assume each floor is 12 ft tall.Slide4

Crime Scene C: The UT Tower is 307 ft tall. A man walking down on the west mall is 365 ft away from the building. A shot was fired at the man at the angle given. Is it possible for this shot to come from the top of the tower? Why?Slide5

Crime Scene D: A rally is being held on the steps of the capitol building. Shots were fired from a building 267 ft away at the given angle hitting a tree 12 ft high. What floor should the police look for evidence on? Slide6

Pattern evidence is generally created by the contact of two surfaces (persons, vehicles, or objects). Result in the formation of:

Impressions

Imprints

Markings

Contact types:

Static (stationary)

Dynamic (moving)

Impression types:

Two dimensional or three dimensional

Types of

Pattern Evidence

for Identification and Comparison

(

Individualization Patterns

)Slide7

Individualization patterns:

Individualization patterns are those which have the potential to be associated with an item or person responsible for it

Fingerprints

Palm prints

Footprints

Handwriting

Toolmarks

Examples of Individualization PatternsSlide8

Conducted

by the

forensic firearms examiner

at the crime lab.

Involves

function and operation of the weapon, association of weapon, bullets and casings.

Often

involves evaluation of ejection patterns and gun shot residue range determinations.

Internal BallisticsSlide9

Conducted

by the

forensic pathologist

.

Involves

defining the path of a bullet through the body, the associated damage and differentiating entry from exit wounds.

Also

includes issues of range determinations.

Terminal BallisticsSlide10

Conducted

by the

crime scene analyst

most often, may involve the firearms examiner.

Involves

defining the path of a bullet through the scene by evaluating various scenes aspects, such as penetrations and perforations, casings and known positions of the victim or shooter.

Ultimately

it defines possible and impossible scenarios for bullet trajectories.

External BallisticsSlide11

Primary concern of external ballistics is evaluating bullet defects.

Trajectory

kits are used to do this, they include:

trajectory rods.

centering guides.

angle finders.

in some cases lasers.

Trajectory KitsSlide12

Verify the defect is a bullet hole.

This

is done based on:

visual examination.

presence of bullets or remnants.

chemical presence of lead or copper.

Utilizing a Trajectory KitSlide13

Insert the rod into a perforating defect.

Use

centering guides to level the rod in the defect.

Lack

of centering guides can affect the angle significantly.

Utilizing a Trajectory Kit

… continuedSlide14

Centering guides are used on both sides of the perforation.

Guides

are not forced into the defect and are held in place by small rubber grommets.

Utilizing a Trajectory Kit

… continuedSlide15

Angle

finder used to document the angle of the trajectory.

Documentation

includes identifying the exact position of defects.

Rods

can be extended several feet without sagging.

Utilizing a Trajectory Kit

… continued