Bloodstain Pattern Analysis Test 1

Splatter

The act of making spatter

Spatter

The result of splattering something

Things BPA can do for an Investigation

1. Indicate weapon type

2. Indicate how many times victim was struck (minimum amount)

3. Location of victim during assault

4. Location of offender before and after event

5. Is bloodstain evidence consistent with medical examiners report?

6. Are bloodstains on suspect’s body and clothing consistent with crime scene?

Angle of Impact Formula

arcsin(stain width/stain length)

Point of Convergence (2D0

Area where the directionality of several stains converge on the surface, with factoring in the angle of impact.

Point of Origin (3D)

1. Stringing method

2. Graphing

3. Trigonometric method

Target Surface

Plays a big part in the shape and size of the stain. Also, how many satellites there are around the original stain.

3 Types of Spatter

1. Low velocity impact spatter (LVIS) : Dripping blood

2. Medium velocity impact spatter (MVIS) : Blunt instrument

3. High velocity impact spatter (HVIS) : Gunshot

Aspirated Blood

Frothy blood found at the crime scene. Oxygen bubbles found in blood spatter or blood found in deceased victim’s mouth or nouse at the crime scene. No bullet hole.

Accompanying Drop

A small blood drop produced as a by-product of drop formation.

Altered Bloodstain

A bloodstain or pattern with characteristics that indicate a physical change has occurred.

Angle of Impact

The acute angle at which a blood drop strikes a target; relative to the plane of the target.

Area of Convergence

The area of intersection in two-dimensions created by lines drawn through the long axis of individual stains; most often associated with an impact pattern.

Area of Origin

The area in three-dimensions of a blood source most often associated with impact pattern.

Back Spatter Pattern

A bloodstain pattern resulting from blood drops that travel in the opposite direction of the external force applied; often associated with entrance would of a gunshot.

Blood Clot

A gelatinous mass formed as a complex mechanism involving red cells, fibrinogen, platelets, and other clotting factors.

Bloodstain

A spot or stain made by blood.

Bloodstain Pattern

A characteristic grouping or distribution of bloodstains which may indicate the manner in which the pattern was deposited.

Bubble Ring

A ring in a bloodstain that results from an air bubble.

Cast-Off Pattern

A bloodstain pattern resulting from blood drops released from a blooded object.

Cessation Cast-Off Pattern

A bloodstain pattern resulting from blood drops released from a bloody object as it suddenly stops.

Directionality

The path of travel of a blood drop indicated by the stains shape.

Directional ANgle

The angle between the long axis of a bloodstain and a reference line on the target.

Drip Pattern

A bloodstain pattern resulting from liquid dripping into liquid, where at least one liquid is blood.

Drip Stain

A bloodstain resulting from the formation and falling of a drop of blood.

Drip Trail

A series of bloodstains that results from blood dripping from, a source that in in horizontal motion.

Edge Characteristics

The physical characteristics at the periphery of a bloodstain that may be described as spines, scalloping, smooth, or irregular margins.

Expirated Pattern

A bloodstain pattern resulting from blood being forced out of the nose, mouth, or wound by air pressure.

Flow Pattern

A bloodstain pattern resulting from the movement of a volume of blood on a surface due to gravity and/or movement of the target.

Forward Spatter Pattern

A bloodstain pattern resulting from blood drops that travel in the same direction as the external force applied; often associated with the exit wound of a gunshot.

Impact Pattern

A bloodstain pattern resulting from an object striking liquid blood.

Insect Stain

Bloodstains produced as the result of insect activity.

Mist Pattern

A bloodstain pattern resulting from blood reduced to a spray of localized micro drops as a result of the force applied; often associated with gunshot injuries.

Parent Stain

The bloodstain from which wave cast-off or satellite bloodstains originate.

Pool

An accumulation of liquid blood on a surface.

Projected Pattern

A bloodstain pattern resulting from, the ejection of a volume of blood under pressure; often associated with a vascular breach.

Satellite Stain

Smaller bloodstains that originate during the formation of the parent stain as a result of blood impacting a surface.

Saturation Pattern

A bloodstain resulting from, the accumulation of liquid blood in an absorbent material.

Serum Stain

The stain resulting from the liquid portion of the blood.

Skeletonized Stain

A bloodstain which has been altered after a period of drying, leaving observable peripheral characteristics of the original stain.

Spatter Stains

Bloodstains resulting from blood drops distributed through the air due to an external force applied to a source of liquid blood.

Splash Pattern

A bloodstain pattern resulting from a volume of liquid blood that falls or spills onto a surface.

Swipe Pattern

A bloodstain pattern resulting from the transfer of blood from a bloodied surface onto another surface, with characteristics that indicate relative motion between the two surfaces.

Target

A surface onto which blood has been deposited.

Transfer Pattern

A bloodstain pattern resulting from contact between a wet bloody surface and another surface.

Void

The absence of blood in an otherwise continuous bloodstain pattern.

Wave Cast-Off Stain

A satellite bloodstain that originates from a parent bloodstain due to the wave-like action of the liquid that occurs when the parent drop strikes a surface at an angle.

Wipe Pattern

A bloodstain pattern resulting from an object moving through a pre-existing bloodstain altering the original stain.