FORENSIC SEROLOGY Forensic serology involves the detection classification

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FORENSIC SEROLOGY Forensic serology involves the detection, classification and study of various bodily fluids

FORENSIC SEROLOGY Forensic serology involves the detection, classification and study of various bodily fluids such as blood, semen, perspiration, and their relationship to a crime scene. A forensic serologist may also be involved in DNA analysis and bloodstain pattern analysis. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 8 -1

The Nature of Blood • The word blood refers to a highly complex mixture

The Nature of Blood • The word blood refers to a highly complex mixture of cells, enzymes, proteins, and inorganic substances. • Plasma, which is the fluid portion of blood, is composed principally of water. • Red blood cells (erythrocytes), white blood cells (leukocytes), and platelets are the solid materials suspended in plasma. • Antigens, usually proteins, are located on the surface of red blood cells and are responsible for blood-type characteristics. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 8 -2

Blood Typing • More than 15 blood antigen systems have been identified, but the

Blood Typing • More than 15 blood antigen systems have been identified, but the A-B-O and Rh systems are the most important. • An individual that is type A has A antigens on his/her red blood cells, type B has B antigens, AB has both A and B antigens, and type O has neither A nor B antigens. • Rh factor is determined by the presence of another antigen, the D antigen. • People having the D antigen are Rh positive; those not having the antigen are Rh negative. • For every antigen there is a specific antibody that will react with it to form clumps known as agglutination. • Thus, if serum containing anti-B is added to red blood cells carrying B antigen, they will immediately react. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 8 -3

Blood Typing • • What’s Your Type? O+ 1 in 3 37. 4% A+

Blood Typing • • What’s Your Type? O+ 1 in 3 37. 4% A+ 1 in 3 35. 7% B+ 1 in 12 8. 5% AB+ 1 in 29 3. 4% O 1 in 15 6. 6% A 1 in 16 6. 3% B 1 in 67 1. 5% AB- 1 in 167. 6% FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 8 -4

Blood Typing • • Compatible Blood Types O- can receive OO+ can receive O+,

Blood Typing • • Compatible Blood Types O- can receive OO+ can receive O+, OA- can receive A-, OA+ can receive A+, A-, O+, OB- can receive B-, OB+ can receive B+, B-, O+, OAB- can receive AB-, A-, OAB+ can receive AB+, AB-, B+, B-, A+, A-, O+, O- FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 8 -5

Blood Typing • • There are four major blood groups determined by the presence

Blood Typing • • There are four major blood groups determined by the presence or absence of two antigens – A and B – on the surface of red blood cells: Group A – has only the A antigen on red cells (and B antibody in the plasma) Group B – has only the B antigen on red cells (and A antibody in the plasma) Group AB – has both A and B antigens on red cells (but neither A nor B antibody in the plasma) Group O – has neither A nor B antigens on red cells (but both A and B antibody are in the plasma) FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 8 -6

Blood Typing • • Compatible Plasma Types O can receive O, A, B, AB

Blood Typing • • Compatible Plasma Types O can receive O, A, B, AB A can receive A, AB B can receive B, AB AB can receive A, B FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 8 -7

Serology • The term serology is used to describe a broad scope of laboratory

Serology • The term serology is used to describe a broad scope of laboratory tests that use specific antigen and serum antibody reactions. • The identity of each of the four A-B-O blood groups can be established by testing the blood with anti-A and anti-B sera. • The concept of specific antigen–antibody reactions has been applied to immunoassay techniques for the detection of drugs of abuse in blood and urine. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 8 -8

Videos Forensic Serology: Blood Basics https: //www. youtube. com/watch ? v=sy. Dx. UAc 0

Videos Forensic Serology: Blood Basics https: //www. youtube. com/watch ? v=sy. Dx. UAc 0 p 7 Q Is It Blood? https: //www. youtube. com/wat ch? v=fx. NR_I 5 IQtg

Blood Spatter Analysis Linda Stefaniak Upper Freehold Regional School District Stefan. L@ufrsd. net October

Blood Spatter Analysis Linda Stefaniak Upper Freehold Regional School District Stefan. L@ufrsd. net October 11, 2006

Stain Patterns of Blood � The crime scene investigator must remember that the location,

Stain Patterns of Blood � The crime scene investigator must remember that the location, distribution, and appearance of bloodstains and spatters may be useful for interpreting and reconstructing the events that produced the bleeding. � Surface texture and the stain’s shape, size, and location must be considered when determining the direction, dropping distance, and angle of impact of a bloodstain.

Stain Patterns of Blood � Surface texture is of paramount importance. In general, the

Stain Patterns of Blood � Surface texture is of paramount importance. In general, the harder and less porous the surface, the less spatter results. � The direction of travel of blood striking an object may be discerned because the pointed end of a bloodstain always faces its direction of travel. � The impact angle of blood on a flat surface can be determined by measuring the degree of circular distortion. At right angles the blood drop is circular, as the angle decreases, the stain becomes elongated. � The origin of a blood spatter in a two-dimensional configuration can be established by drawing straight lines through the long axis of several individual bloodstains. The intersection or point of convergence of the lines represents the origin point.

Bloodstain Pattern Analysis (BPA) � While the use of bloodstains as evidence is not

Bloodstain Pattern Analysis (BPA) � While the use of bloodstains as evidence is not new, the application of modern science has brought it to a higher level. � New technologies (DNA analysis) are available for detectives and criminologists to use in solving crimes and apprehending

Bloodstain Pattern Analysis (BPA) �BPA applies scientific knowledge from other fields to solve practical

Bloodstain Pattern Analysis (BPA) �BPA applies scientific knowledge from other fields to solve practical problems. �Draws from biology, chemistry, math and physics

BPA can determine: �Location and description of individual stains and patterns �Mechanism that created

BPA can determine: �Location and description of individual stains and patterns �Mechanism that created the stains �Direction a blood droplet was traveling �Area of origin �Type of object used in attack �Minimum number of blows �Presence of a subject at a scene �Positioning of the victim, suspect and objects during events

Determining angles of impact �Blood droplets in freefall have the shape of a sphere.

Determining angles of impact �Blood droplets in freefall have the shape of a sphere. �Droplets striking surfaces and leaving well-formed stains make it possible to determine the angle at which the droplet struck the surface.

Determining angles of impact � A well-formed stain is in the shape of an

Determining angles of impact � A well-formed stain is in the shape of an ellipse � The ratio between the length-width of the ellipse is the function of the sine of the impact angle � Accurately measuring the stain gives this impact angle

Point and area of convergence �The point of convergence is the intersection of two

Point and area of convergence �The point of convergence is the intersection of two bloodstain paths, where the stains come from opposite sides of the impact pattern

Point and area of convergence �The area of convergence is the box formed by

Point and area of convergence �The area of convergence is the box formed by the intersection of several stains from opposite sides of the impact pattern.

Point and area of convergence �Point (Area) of Origin – the common point (area)

Point and area of convergence �Point (Area) of Origin – the common point (area) in three dimensional space to which the trajectories of several blood drops can be retraced.

Target surface texture �Bloodstains can occur on a variety of surfaces, such as carpet,

Target surface texture �Bloodstains can occur on a variety of surfaces, such as carpet, wood, tile, wallpaper, clothing…. . �The type of surface the blood strikes affects the amount of resulting spatter, including the size and appearance of the blood drops.

Target surface texture �Blood droplets that strike a hard smooth surface, like a piece

Target surface texture �Blood droplets that strike a hard smooth surface, like a piece of glass, will have little or no distortion around the edge.

Target surface texture �Blood droplets that strike linoleum flooring take on a slightly different

Target surface texture �Blood droplets that strike linoleum flooring take on a slightly different appearance. �Notice scalloping around the edge of the blood droplets.

Target surface texture �Surfaces such as wood or concrete are distorted to a larger

Target surface texture �Surfaces such as wood or concrete are distorted to a larger extent. �Notice the spines and secondary spatter present.

Blood Drops vs. Angle on Manila Folder

Blood Drops vs. Angle on Manila Folder

Blood Drops vs. Angle on Paper

Blood Drops vs. Angle on Paper

Bloodstain pattern categories � Classifies stains based on the mechanism that created them. �Passive

Bloodstain pattern categories � Classifies stains based on the mechanism that created them. �Passive bloodstains are created when the force acting on the blood is gravity �Projected bloodstains occur when some form of energy has been transferred to a blood source �Transfer or contact is produced when an object with blood on it comes into contact with an object or a surface that does not have blood on it.

Passive drops A bloodstain drop(s) created or formed by the force of gravity acting

Passive drops A bloodstain drop(s) created or formed by the force of gravity acting alone.

Drip pattern A bloodstain pattern that results from blood dripping into blood

Drip pattern A bloodstain pattern that results from blood dripping into blood

Flow pattern A change in the shape and direction of a bloodstain due to

Flow pattern A change in the shape and direction of a bloodstain due to the influence of gravity or movement of the object

Low Velocity Impact (LVI) Relatively large stains 4 mm in size and greater. Impact

Low Velocity Impact (LVI) Relatively large stains 4 mm in size and greater. Impact velocity up to 5 feet/sec

Medium Velocity Impact (MVI) Preponderant stain size 1 to 4 mm size. Impact velocity

Medium Velocity Impact (MVI) Preponderant stain size 1 to 4 mm size. Impact velocity of 5 to 25 feet/sec.

High Velocity Impact (HVI) Preponderant stain size 1 mm in size and smaller. Mist

High Velocity Impact (HVI) Preponderant stain size 1 mm in size and smaller. Mist like appearance. Impact velocity of 100 feet/sec and greater.

Cast-off pattern A bloodstain pattern created when blood is released or thrown from a

Cast-off pattern A bloodstain pattern created when blood is released or thrown from a blood-bearing object in motion

Arterial spurting or gushing Bloodstain pattern(s) resulting from blood exiting the body under pressure

Arterial spurting or gushing Bloodstain pattern(s) resulting from blood exiting the body under pressure from a breached artery

Back spatter and expiratory blood �Back spatter – blood directed back towards the source

Back spatter and expiratory blood �Back spatter – blood directed back towards the source of energy or force that caused the spatter �Expiratory blood – blood that is blown out of the nose, mouth or a wound as a result of air pressure and/or air flow which is the propelling force

Swipe pattern The transfer of blood from a moving source onto an unstained surface.

Swipe pattern The transfer of blood from a moving source onto an unstained surface. Direction of travel may be determined by the feathered edge.

Hair swipe pattern The transfer of blood from a moving source onto an unstained

Hair swipe pattern The transfer of blood from a moving source onto an unstained surface. Direction of travel may be determined by the feathered edge.

Wipe pattern A bloodstain pattern created when an object moves through an existing stain,

Wipe pattern A bloodstain pattern created when an object moves through an existing stain, removing and/or altering its appearance.

Transfer pattern A bloodstain pattern created when a wet, bloody surface comes in contact

Transfer pattern A bloodstain pattern created when a wet, bloody surface comes in contact with a second surface. A recognizable image of all or a portion of the original surface may be observed in the pattern. When a wet bloodied object comes in contact with a non-bloodied surface, some blood will be transferred from the object to the surface. In some cases the resulting transfer pattern may have enough detail to identify the object that created the stain.

Transfer pattern A bloodstain pattern created when a wet, bloody surface comes in contact

Transfer pattern A bloodstain pattern created when a wet, bloody surface comes in contact with a second surface. A recognizable image of all or a portion of the original surface may be observed in the pattern. When a wet bloodied object comes in contact with a non-bloodied surface, some blood will be transferred from the object to the surface. In some cases the resulting transfer pattern may have enough detail to identify the object that created the stain.

https: //www. youtub e. com/watch? v=KS pe. G 145 D-k Video Blood Spatters 101

https: //www. youtub e. com/watch? v=KS pe. G 145 D-k Video Blood Spatters 101 (7: 09)

Sources �BPA Tutorial http: //www. bloodspatter. com/BPATutorial. htm �Blood Pattern Analysis (Wikipedia, I kid

Sources �BPA Tutorial http: //www. bloodspatter. com/BPATutorial. htm �Blood Pattern Analysis (Wikipedia, I kid you not!) http: //en. wikipedia. org/wiki/Blood_pattern_ana lysis_at_crime_scenes �International Association of B. P. Analysts http: //www. iabpa. org/

Knowledge Check List three factors that determine the appearance of a passive blood drop.

Knowledge Check List three factors that determine the appearance of a passive blood drop. § surface texture § direction of travel of blood § impact angle

Knowledge Check What are “stem cells? ” Stem cells are a class of undifferentiated

Knowledge Check What are “stem cells? ” Stem cells are a class of undifferentiated cells that are able to differentiate into specialized cell types. Commonly, stem cells come from two main sources: • Embryos formed during the blastocyst phase of embryological development (embryonic stem cells) and • Adult tissue (adult stem cells). Both types are generally characterized by their potency, or potential to differentiate into different cell types (such as skin, muscle, bone, etc. ).

Knowledge Check List some things that BPA can determine. § Location and description of

Knowledge Check List some things that BPA can determine. § Location and description of individual stains and patterns § Mechanism that created the stains § Direction a blood droplet was traveling § Area of origin § Type of object used in attack § Minimum number of blows § Presence of a subject at a scene § Positioning of the victim, suspect and objects during events § Sequence of events

Knowledge Check In BPA studies, what is meant by the “point of convergence? ”

Knowledge Check In BPA studies, what is meant by the “point of convergence? ” the intersection of two bloodstain paths, where the stains come from opposite sides of the impact pattern

Knowledge Check What can you say about this blood drop? Blood droplets that strike

Knowledge Check What can you say about this blood drop? Blood droplets that strike a hard smooth surface, like a piece of glass, will have little or no distortion around the edge.

Knowledge Check What can you say about this blood drop? Surfaces such as wood

Knowledge Check What can you say about this blood drop? Surfaces such as wood or concrete are distorted to a larger extent. Notice the spines and secondary spatter present.

Knowledge Check What can you say about this blood drop? Impact velocity of 100

Knowledge Check What can you say about this blood drop? Impact velocity of 100 feet/sec and greater