PPT-The Science of Blood Spatter

Spatter Definition What is impact spatter A blood stain produced when an object makes forceful contact with a source of blood projecting blood outward from the source Why do we care Why is impact spatter important. Blood pressure normally rises and falls throughout the day but it can cause health problems if it stays high for a long time High blood pressure can lead to heart disease and strokeleading causes of death in the United States Are you at risk One in WARNING. Contains graphic images. Angle of Impact. The acute angle formed between the direction of a blood drop and the plane of the surface it strikes. . Arterial spurting (or gushing) pattern. . Bloodstain pattern(s) resulting from blood exiting the body under pressure from a breached . FSB 09 Room plan room. The crime scene investigators determined that the bloodstain patterns on the “stove” wall were suitable for analysis. To enable you to analyse these bloodstains a General Info gained from bloodstain pattern analysis:. 1. the direction the blood originated from. 2.the angle that the blood drop struck a surface. 3. location/position of a bleeding individual at a crime scene. Chapter 8. Blood Spatter . #1…it’s not “. splatter. ”! . . Properties of blood affect pattern:. Fairly . high surface . tension (cohesion). Very . viscous. Sticky-adheres . to external . surface (adhesion). Ms. Schultz. The Sam Sheppard Case. On July 4, 1954 Sam Sheppard called police to report that his wife Marilynn was dead in the bedroom. He said the night before, his wife had gone upstairs to bed while he was asleep on the couch. When he went upstairs, he saw his wife covered in blood. He heard a noise and ran downstairs chasing after a 6’3’’ bushy haired man. The two struggled and Dr. Sheppard was choked unconscious. When police arrived, Marilynn was found with 35 wounds to the head and blood drenched the walls, door, and bed. Her face was almost unrecognizable. Sheppard served 10 years in prison before the US Supreme court rules that the trial had been tainted. The evidence was reexamined. Blood spatters and blood drops provided some of the most compelling evidence. Dr. Paul Kirk, an expert in blood analysis, determined the killer could not have been Sam because the attack was perpetrated by a left handed person. Dr. Sheppard was right handed.. Bits and pieces…. Use of force to describe the blood spatter. In the past, forensic investigators used ‘velocity’ to describe a pattern of blood dispersion. . Low . velocity (gravity/drop, 5ft/s) . Bloodstain Science. T. Trimpe 2006 http://sciencespot.net/. Warning: Some material in this presentation and related videos may be too graphic for some people. . What . does the abbreviation BPA represent? . Class Starter: . What are the different blood types that exist?. What determines what type of blood you have?. Why can you die if you were to receive an incompatible blood type?. What determines the different blood groups?. October . 14, 2014. Points of origin and convergence. The source of blood spatter can be localized by following the direction of travel of several stains.. Direction of trave. l . The narrow end of an elongated . SFS1. Students will recognize and classify various types of evidence in relation to the definition and scope of Forensic Science.. SFS2. Students will use various scientific techniques to analyze physical and trace evidence.. Blood Stain Evidence. Bloodstain patterns can help investigators reconstruct events in a crime scene.. Analysis of the blood stain can tell whether it is animal or human.. Projected blood stains are called . Plasma. fluid portion of normal . unclotted. blood . red blood cells, white blood cells, and platelets are suspended in it. BLOOD COMPONENTS. Serum. liquid portion of clotted blood. SURFACE TENSION OF BLOOD. Blood Vessels P A R T A Blood vessels and circulation Blood is carried in a closed system of vessels that begins and ends at the heart 5 types of blood vessels Arteries – carries blood away from the heart