Chapter 10 Bloodstain Patter Analysis

Front 1

Violent contact between individuals at a crime scene frequently produces bleeding and results in the formation of _.

Back 1

bloodstain patterns

Front 2

The proper interpretation of bloodstain patterns necessitates carefully planned _ using surface materials comparable to those found at the crime scene.

Back 2

control experiments

Front 3

Bloodstain patterns may convey to the analyst the location and movements of _ and _ during the commission of a crime.

Back 3

victims; suspects

Front 4

Generally, bloodstain diameter _ with height.

Back 4

increases

Front 5

The _ and _ of blood striking an object may be discerned by the stain’s shape.

Back 5

directionality; angle of impact

Front 6

A drop of blood that strikes a surface at an angle of impact of approximately 90 degrees will be close to _ in shape.

Back 6

circular

Front 7

The angle of impact of an individual bloodstain can be estimated using the ration of _ divided by _.

Back 7

width ; height

Front 8

_ is the most common type of blood spatter found at a crime scene and is produced when an object forcefully contacts a source of blood.

Back 8

Impact spatter

Front 9

The classification of impact spatter based on the size of droplets and from the velocity of an applied force are, _ _ & _ impact spatters.

Back 9

low velocity, medium velocity, and high velocity

Front 10

The _ is the point on a two-dimensional plane from which the drops originated.

Back 10

area of convergence

Front 11

The _ of a bloodstain pattern in a three-dimensional space illustrates the position of the victim or suspect when the stain-producing event took place.

Back 11

area of origin

Front 12

The _ method is used at the crime scene to determine the area of origin.

Back 12

string

Front 13

True/False: Harder and less porous surfaces result in less spatter, whereas rough surfaces result in stains with more spatter and serrated edges.

Back 13

True

Front 14

True/False: Forward spatter consists of the blood projected backward from the source, and back spatter is projected outward and away from the source.

Back 14

False

Front 15

True/False: The velocity of an applied force is a good way to classify impact patterns and to determine the kind of force that produced them.

Back 15

False

Front 16

A _ is created by contact between a bloody object and a surface.

Back 16

transfer pattern

Front 17

The pattern made by a bloody object dragged across a surface _ as the object moves away from the point of contact.

Back 17

lightens

Front 18

The approximate drying time of a _ of blood determined by experimentation is related to the environment conditions of the scene and may suggest how much time has elapsed since it’s deposition.

Back 18

pool

Front 19

The edges of a bloodstain will generally _ within 50 seconds of deposition and be left intact even if the central area of a bloodstain is altered by a wiping motion.

Back 19

skeletonize

Front 20

A _ pattern commonly originated from repeated strikes from weapons or fists and is characterized by an arc pattern of separate drops showing directionality.

Back 20

cast-off

Front 21

When an injury to an artery is suffered, the pressure of the continuing pumping of blood projects blood out of the injured area in spurts, creating a pattern known as _ .

Back 21

arterial spray spatter

Front 22

If an _ pattern is found at a scene, it may show movement, lead to a discarded weapon, or provide identification of the suspect by his or her own blood.

Back 22

trail

Front 23

A bloodstain pattern created by _ features bubbles of oxygen in the drying drops and may be lighter in color than impact spatter.

Back 23

expirated blood

Front 24

The shape and size of the blank space, or _ created when an object blocks the deposition of spatter onto a surface and is then removed may give clue about the size and shape of the missing object or person.

Back 24

void

Front 25

*When documenting bloodstain patterns, the _ involves setting up a grid of squares of known dimensions over the entire pattern and taking overview, medium-range, and close-up photographs with and without the grid.

Back 25

grid method

Front 26

The _ of bloodstain documentation involves setting up a border of rulers around the pattern and then placing small ruler next to each stain to show relative position and size in photos.

Back 26

perimeter ruler method

Front 27

True/False: Footwear transfer patterns created by an individual who was running typically show imprints with more space between them than those of an individual who was walking

Back 27

True

Front 28

True/False: The direction of a flow pattern may show movements of objects or bodies while the flow was still in progress or after the blood has dried.

Back 28

True

Front 29

True/False: Characteristics of a cast-off pattern arc cannot give clues about the kind of object that was used to produce the pattern.

Back 29

False

Front 30

True/False: Each bloodstain pattern found at a crime scene should be noted, studied, and photographed.

Back 30

True

Front 31

True/False: The pointed end of a bloodstain always faces towards its direction of travel.

Back 31

True

Front 32

Angle of impact

Back 32

The angle of the source of the blood to the surface where it was deposited. It can be estimated from the width-to-length ration of the stain to help determine the position of the victim or the weapon at the time when the bleeding wound was inflicted.

Front 33

Area of convergence

Back 33

The area on a two-dimensional plan where lines traced through the long axis of several individual bloodstains meet. This approximates the two-dimensional place from which the bloodstains were projected.

Front 34

Area of origin

Back 34

The location in three dimensional space that produced a bloodstain originated from. The location of the area of convergence and the angle of impact for each bloodstain is used to approximate this area.

Front 35

Arterial spray

Back 35

A bloodstain spatter found at a crime where a victim suffered injury to an artery.

Front 36

Cast-off

Back 36

A bloodstain pattern that is created when blood is flung from a blood-bearing object in motion onto a surface.

Front 37

Expirated blood pattern

Back 37

The pattern created by blood that is expelled out of the nose, mouth, or respiratory system as a result of air pressure and/or airflow.

Front 38

Flow

Back 38

A bloodstain pattern formed by the movement of small or large amounts of blood as a result of gravitational pulls.

Front 39

Skeletonization

Back 39

The process by which the edges of bloodstain dry to the surface in a specific period of time (dependent on envoi. and surface conditions). It will remain apparent even after the rest of the bloodstain has been disturbed from its original position.

Front 40

Void

Back 40

An area within a deposited spatter pattern that is clear of spatter, caused by an object of person’s blocking the area at the time the spatter’s deposition.

Front 41

Impact spatter

Back 41

A bloodstain pattern produced when an object makes forceful contact with a source of blood, projecting droplets of blood outward from the source.

Front 42

Forward spatter

Back 42

Blood that travels away from the source in the same direction as the force that caused the spatter.

Front 43

Satellite spatter

Back 43

Blood spatter around parent stain, with blood droplets whose pointed ends face against the direction of travel.

Front 44

Back spatter

Back 44

Blood directed back toward the source of the force that caused the spatter.

Front 45

High-velocity spatter

Back 45

An impact spatter pattern created by a force traveling at 100 feet per second or faster and producing droplets with diameters of less than 1 millimeter.

Front 46

Medium-velocity spatter

Back 46

An impact spatter pattern created by a force traveling at 5 to 25 feet per second and producing drops with diameters of between 1 and 4 millimeters.

Front 47

Low-velocity spatter

Back 47

An impact spatter pattern created by a force traveling at 5 feet per second or less and producing drops with diameters of greater than 4 millimeters.

Front 48

Drop trail pattern

Back 48

Drops of blood formed by dripping off other objects.

Front 49

Transfer pattern

Back 49

A bloodstain pattern created when a wet, bloody surface comes in contact with a second surface.