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Bloodstain Pattern Presentation I have an interest in this section of law enforcement for three main reasons: The excitement of never knowing what is next, something different is always occurring. Bringing justice to victims and answers to their families. Science is constantly evolving, bringing new innovations to crime solving. I. As quoted by forensic scientist Dr. Henry C. Lee, “Forensic science is used to predict not the future but the past.” a) Relying on evidence and its scientific analysis, forensic science is an essential part of the criminal justice system. Forensic science relies on a number of wide ranging disciplines and methods in order to achieve its goals; bloodstain pattern analysis is one small part of a much larger group of individuals that come together for the purposes of crime scene investigation. b) Bloodstain pattern analysis is the examination of the shapes, locations, and distribution patterns of bloodstains, in order to provide an interpretation of the physical events which gave rise to their origin. c) This presentation will be a very, very brief look into bloodstain patterns. We will go over a few different types of bloodstain patterns and terms used in the analysis of these patterns. II. The shape and location of bloodstains provide clues about where the victim and suspect were when the crime took place and where they went afterward. a) Information these patterns provide: Origin of the bloodstain The type of instrument used Direction from which a victim was struck Relative positions of the victim, assailant or assailants, and bystanders Location and movements during the attack Number of blows or gunshots the victim received Test of truthfulness of suspects and witnesses b) Categories of bloodstains: 1) Passive: Forms not because of force but because of laws of gravity. Passive drop-blood drop created or formed by force of gravity Drip pattern-a pattern which results from blood dripping into blood Flow pattern-a change in shape and direction of a bloodstain due to the influence of gravity or movement 2) Transfer: Created when a wet, bloody surface comes into contact with a secondary surface. Sometimes a recognizable image of all or some of the original surface can be observed in the pattern, such as a bloody hand or footwear. Transfer/Contact Swipe-the transfer of blood from a moving source onto an unstained surface Wipe-created when a object moves through an existing stain, removing or altering its appearance 3) Projected: Created when an exposed blood source is subjected to an action or force, greater than the force of gravity. The size, shape, and number of resulting stains will depend, primarily, on the amount of force utilized to strike the blood source. Low velocity impact spatter Medium velocity impact spatter-a beating typically causes this type High velocity impact spatter-examples would be a gunshot or high-speed machinery Cast-off-created when blood is released or thrown from a blood bearing object in motion Arterial spurting or gushing-pattern resulting from blood exiting the body under pressure from a breached artery Back spatter-blood that is directed back to the source of energy or force that caused the spatter Expiratory blood-blood that is blown out the nose, mouth, or a wound as a result of air pressure or airflow as the propelling force IV. In conclusion, bloodstain pattern analysis involves the study of blood spatters on walls, floors, furniture, and other objects to determine the events that occurred at a crime scene. The goal of the reconstruction of the crime scene using bloodstain analysis is to assist the overall forensic investigation with the questions that must be addressed, such as; what occurred, where it occurred, when and in what sequence, who was there, who was not there, and what did not occur. Blood is one of the most significant and frequently encountered types of physical evidence associated with death and violent crime scene investigations. The analysis of bloodstain pattern evidence is crucial in cases where the manner of death is in question and the issue of homicide, suicide, accident, or natural death must be resolved.