Serology Allie Wheeler, Amber Conrad, Aleisha Murrell, Harsha Pinnamaraju, Orin Sparks, Jonathan Huynh, Kyle Eberle Table of Contents Introduction…1 Objectives and Goals…2 Educational Requirements…3 Analytical Procedure…4 Presumptive Test…5 Blood Typing…8 Interpreting Blood Stain Patterns…12 Crime Scene Reconstruction…16 Glossary…23 Introduction The following information presented is to help understand serology, the study of blood, in forensic science. Blood is the most common piece of evidence found at a crime scene and is key to solving any crime. The following information is presented: Blood Typing Blood Spatter Crime Scene Reconstruction Educational Requirements to be an Expert in this Field And much more! AW Objective and Goals Forensic Serology is dedicated to providing forensic analysis of physical evidence to the criminal justice system. Specialists analyze evidence, usually associated with blood, to identify any suspects. Tests and analysis are performed in controlled environment using proper procedures in order to get accurate and relevant analytical results. HP,OS Educational Requirements Requirements for a general careers in this field: formal education equivalent of a bachelor's degree in chemistry or closely related field bachelor's degree in biology two years experience in a forensic laboratory approval of the S.O.M. School of Medicine HP,OS Analytical Procedures Collection from Clothing or Other Items Visual examine item Take care to preserve evidence and other sections such as blood, stains, and latent prints At this point, you may use tape to remove stray hairs and dust off the fiber Label tape lifts Identify fiber type and color Place in envelope to store HP,OS Presumptive Tests They are preliminary tests/field tests Establishes possibility of a specific bodily fluid’s presence Do not conclusively prove the presence Pros: Narrows possibilities Can be used on larger areas Can locate possible evidence not visible to naked eye Cons: Risk of false positives and may be overly sensitive HP,OS Presumptive Tests Phenolphthalein Test Aka: Kastle Meyer Test A Phenolphthalein solution is used to show the possible presence of blood based upon a reaction of hemoglobin which produces a pink color. Precautions: This test is presumptive because it has produced false positives HP,OS Presumptive Tests LuminolTest Luminol is used in solution or sprayed onto suspected surfaces. This compound gives a strong blue fluorescence (glows)when viewed with a UV light. It is used o find blood reminants Precautions: False positives have been observed with the presence of copper salts HP,OS Blood Typing Blood Type Antigens of Red Blood Cells Antibodies in Serum A A Anti- B B B Anti- A AB AB Neither Anti- A nor Anti- B O Neither A or B Both Anti- A and Anti- B Anti- A Serum Anti- B Serum + + Whole Blood Whole Blood Antigen Present Blood Type + - A A - + B B + + A and B AB - - Neither A nor B O KE Universal Types People with type AB blood are called universal recipients No antibodies present Can receive blood from anybody People with type O blood are called universal donors No antigens present Can donate blood to anybody KE Interpreting Blood Stain Patterns Satellite Spatter: Small droplets of blood that are distributed around the perimeter of a drop/drops of blood and were produced as a result of the blood impacting the target surface Skeletonization: The outside of a blood droplet will harden before the center Drip Trail Pattern: A pattern of bloodstains formed by the dripping of blood of a moving surface or person in a recognizable pathway separate from other patterns AM,AC Interpreting Blood Stain Patterns Arterial Spatter: A characteristic blood stain pattern containing spurts that result from blood exiting under pressure from an arterial injury Expirated Blood Pattern: A pattern created by blood that expelled out of the nose, mouth, or respiratory system as a result of air pressure and/or air flow Void: Something that takes the place of the blood at a crime scene AM,AC Interpreting Blood Stain Patterns Transfer: A bloodstain pattern created when a wet, bloody surface comes in contact with a second surface. Low Velocity Spatter: Blood that falls at a normal gravity speed, typically from an open wound High Velocity Spatter: Blood that is flown at a speed greater than that of gravity that is associated with high-speed collisions, such as gunshots or explosions AM,AC Interpreting Blood Stain Patterns Impact Spatter: a random pattern of spatter of varying sizes Forward Spatter: Blood that travels away from the source in the same direction as the force that caused the spatter Back Spatter: Blood directed back toward the source of the force that caused the spatter AM,AC What is Crime Scene Reconstruction? The use of scientific methods, physical evidence, deductive reasoning and their interrelationships to gain explicit knowledge of the series of events that surround the commission of a crime. JH Who Participates In Crime Scene Reconstruction? Reconstructing consists of the following: Medical Examiner Experienced Law Enforcement Personnel Criminalists JH Steps of Crime Scene Reconstruction Recognition of evidence Documentation of evidence Collection of evidence Evaluation of evidence Hypothesis Testing Reconstruction JH Crime Scene Reconstruction The criminalist must be prepared to answer the following questions when examining dried blood Is it blood? From what species did the blood originate? If the blood is of human origin, how closely can it be associated to a particular individual Detection of blood is best made by means of a preliminary color test KE Things To Consider At The Crime Scene Origin(s) of bloodstain Distance of bloodstain from target Direction from which blood impacted Speed with which blood left source Position of victim and assailant Movement of victim and assailant Number of blows/shots KE Which type of blood? Once the stain has been characterized as blood, the precipitin test will determine whether the stain is of human or animal origin Once the bloodstain has been determined to be of human origin, the blood is typed Test For Human Blood KE Blood Group Characteristics Based on 2 glycolipid antigens (A & B) found on the surfaces of RBC Antigen A only= type A blood Antigen B only= type B blood Both antigens= type AB blood No antigens= type O blood KE Glossary Agglutination: the clumping together of red blood cells by the action of an antibody Angle of Impact: acute or internal angle formed by the direction of a blood drop and the plane of the surface it strikes Antibody: a protein in the blood serum that destroys or inactivates a specific antigen Antigen: a substance, usually a protein, which stimulates the body to produce antibodies against it Anti-Serum: blood serum that contains specific antibodies Area of Convergence: The area containing the intersections generated by lines drawn through the long axes of individual stains that indicates in two dimensions the location of the blood source. Area of Origin: the location of the blood source in 3-D perspective Arterial Spray: Bloodstain pattern(s) resulting from blood exiting the body under pressure from a breached artery Back Spatter: A bloodstain pattern resulting from blood drops that traveled in the opposite direction of the external force applied; associated with an entrance wound created by a projectile. Blood Drops: gravity acts on the blood until it impacts a horizontal surface Blood Smears :these happen when a bleeding person is moved Blood Splashes: blood that has been thrown through the air until it struck a surface at angle AW Glossary Cont. Blood Spurts: this is result of arterial bleeding Blood Trails: blood that is deposited when a wounded person walks or runs while dripping blood. It can also happen from carrying or dragging a body Drip Trail: A bloodstain pattern resulting from the movement of a source of drip stains between two points. Forward Splatter: A bloodstain pattern resulting from blood drops that traveled in the same direction as the impact force. High-Velocity Impact Spatter: bloodstains resulting from blood with a velocity in excess of 100 ft per sec Impact Spatter: A bloodstain pattern resulting from an object striking liquid blood. Low-Velocity Impact Spatter: bloodstains resulting from blood with a velocity of 5 ft per sec or less Luminal: a liquid that reacts to UV lighting and reveals that traces of blood Medium Velocity Impact Spatter: bloodstains resulting from blood with a velocity of 5 ft to 25 ft per sec Plasma: the liquid part of the blood Pools of Blood: these pools are next to the body and may indicate if the body has been moved AW Glossary Cont. Satellite Spatter: A smaller bloodstain that originated during the formation of the parent stain as a result of blood impacting a surface Serology: the scientific study of blood Skeletonization: A bloodstain consisting of a darkened peripheral rim where the center of the stain is no longer intact. Spattered Blood: a random distribution of bloodstains that vary in size that may be produced by a variety of mechanisms Transfer Patterns: A bloodstain resulting from contact between a blood-bearing surface and another surface Void: An absence of blood in an otherwise continuous bloodstain or bloodstain pattern. AW Works Cited http://hemospat.com/terminology/index.php?cat=misc&s ub=skeletonized http://www.crimeandclues.com/index.php/forensic- science-a-csi/crime-scene-investigation/crime-scenereconstruction/4-introduction-to-crime-scenereconstruction http://www.wisegeek.com/what-are-the-differentcrime-scene-investigator-jobs.htm http://www.cienciaforense.com/Pages/CrimeScene/C SReconstruction.htm