Crime Scene Final

Pattern diversity principle

the Variations in combinations of blood volumes and forces acting on those volumes lead to recognizable classes of patterns

road mapping

the blood patterns overall orientation in the scene and the entire pattern.

chamber

the location of the firearm that hold the cartridge when it is fired

F stop

the setting of an adjustable lens aperture, indicated by an F number

Cartridge case

the subunit of the cartridge that holds the primer and propellant

projectile/ bullet

the subunit of the cartridge that is expelled form the firearm under the pressure created by the burning propelant

Barrel

the tubular aspect of the firearm that directs the path of the projectile when fired from the firearm

Vertical angle or angle of elevation

this is the able of the muzzle in relation to the target using a vertical reference line

Horizontal angle or angle of departure

this is the angle of the muzzle in relation to the target using a horizontal line

Blue light (485-530 nm)

used with orange barrier filter to see biological fluids, fibers or hairs to flouresce

Nonporous rough surfaces

vinyl, leather, textured surfaces

Near- UV and violent- blue light (415- 485 nm)

when combined with yellow filter, can search for bitemarks and bruises

Zone 3

-An area impossible given data -shooter is physically unable to align barrel and produce the trajectory

Base line coordinates

-Best suited for exterior scenes with out evident landmarks -begins with a datum point and extended along cardinal direction

Elevation Sketch

-Drawn depicting the side view of some portion of the scene, typically an interior wall similar vertical structure

Polar conditions

-Effective in exterior scene with significantly scattered evidence -using sighting device, tech measures two-three measurements from the known point to evidence in questions

ISO

-International Standardization Organization -indicates the light sensitivity on the films emulsion

External and exterior ballistics

-Path and trajectory of the bullet after laving the barrel of the weapon to its final impact

Wake effect/pinch point

-Pinch point: point where the bullet and metal first meet and a small island of paint survives -Wake effect: small fracture lines in the paint and on occasion the metal arcs away from the defect

Triangulation

-Regular: fixed with minimum of 4 measurements -irregular: measurements from center mass to distinct landmarks

Orange- red (570-700 nm)

-Viewing inks on items present in scene -substances bruising

Zone 2

-area considered awkward but possible -higher than shooters shoulder

Rectangular Coordinates

-best suited for crime scenes with clear and specific boundaries -interior -fixes evidence by measuring right angles from the evidence to the surrounding walls and surfaces

internal or interior ballistics

-firearm itself -forensic firearm examiners -ejection patterns, gunshot residue deposition

Latent prints

-invisible; occurs as oils and secretions from friction ridge surfaces being deposited through contact

Defining the bullet impact angle based on the defect shape

-the shape of a bullet defect indicates the angle of the impact -the inverse SIN of N is equal to the approx impact angle

Cross- examination exploded sketch

Combines standard birds eye view of the horizontal surfaces of the room, while at the same time laying down the walls to depict evidence on vertical surfaces

class characteristics

General characteristics that define a category of objects, excludes items ex: hair color, shoe size

intermediate range

Muzzle between 5-80 inches -stippling around wound

Near contact

Muzzle generally said to be not more than 5 inches from the skin

Close contact or hard contact

Muzzle indirect contact with skin or pressed into skin

Loose contact

Muzzle is extremely close proximity to skin, but small gap at moment of firing

Heading

Notation that indicates why the sketch was created

Three dimensional Sketch

Offers an ability to present the crime scene information in a more realistic perspective

Physically Altered Bloodstain Principle

Once exposed, blood will react to the environmental conditions in predictable manner.

Porous surfaces

Paper, cardboard, untreated wood

Indeterminate range

no conclusion can be drawn about muzzle distance -no marking except for bullet defect

Title block

Provides important information relevant to the location of the scene and the creator of the sketch

Legend

Tells the viewer what the various labels used in the diagram depict

Sub principle of impact angle

The collapse of a free flight droplet on a surface produces a stain with a circular or elliptical shape

Infrared (700-2000nm)

questioned documents

RUVIS (180-254 nm)

reflecting UV imaging systems -allows visualization of latent prints before dusting or development on most non porous

Principle of stain shape and vector correlation

The shape of a certain bloodstains provides indicators as to the direction of deposition as well as to the spacial origin of the blood

Plastic prints

True dimensional impression -wax, puddy

Nonporous smooth surfaces

Varnished and painted surfaces, plastic surfaces, glass

Patent prints

Visible prints -blood, paint

Cartridge

a complete unit of an unfired ammunition

Environmental conditions

Any weather or scene conditions noted at time of the investigation

Theory of bloodstain pattern analysis

Blood as a fluid responds to variations of internal and external forces in a predictable fashion

Additional Exams

Describe any condition evals of exams, dependent upon the specifics of the crime

Characteristics of the scene

Description of scene and associated features of the scene such as doors windows, openings and geographical features of the exterior scenes and their relationships to the surrounding areas

Diagram area

Drawing itself

Scene documentation

Intended to describe the basic efforts taken to photograph and sketch the scene

Conditions of the scene

Intended to identify the specific conditions that are pertinent to the investigation

Longwave uv (365-415 nm)

als, bloodstain

Special conditions

anomalies, human skin, adhesive tape and blood prints

Zone 1

area considered most probable of where shooter could have shot

ejection port

associated with semiautomatic and automatic weapons, the ejection port is where the expended casing is ejected from the chamber

Terminal ballistics

effect of bullet on human target and includes defining path of bullet through victim

individual characteristics

exceptional characteristics that may establish uniqueness of an object Ex: tread ware on a shoe

Factors pertinent to entry/exit

intend to deal with both known and unknown possible avenues of approach and departure from the scene