Oct 04, 2016 since blood evidence associated with a crime can provide information that may solve the case, it is essential to correctly document, collect, and preserve this type of evidence. The forward spatter involved will be more symmetrical than the back spatter due to the primary force of the impact being transmitted in the direction of the projectile. Pdf analytical analysis of blood spatter trajectory for. The force must be great enough to overcome the surface tension of the blood. An overview covering dna and how it is tested in the lab.
If we combine all the constants into one term k, we can write. Despite these amendments the manual method of measuring is still. Parent drop spines satellite spatter parent drop the droplet from which a. Blood droplets analyzed to give clues to the location of a crime, movement of a victim, and type of weapon. Bloodspatter expert testifies in yoga store killing the. Apr 30, 2012 i, personally, have no respect for bevels socalled scientific opinion. This blood is also tested to determine if the blood came from the victim or the suspect. Bloodstain pattern analysis bpa is a forensic application of the interpretation of distinct patterns. Kemtec forensic blood spatter kit blood spatter kit. The lead detective will see that all the data including sketch is compiled into one report for submission. The distance between the spatter and the blood source is found out by proposed method by use of the image processing. The national academies of science report on forensics in the us states, the uncertainties of blood spatter evidence are enormous. Just like the track impression evidence, the historic origin and development of bpa bloodstain pattern analysis is believed to date back from the early mans hunting efforts.
One subset of forensics is bloodstain pattern analysis bpa, i. Mar 03, 2005 retired crime lab technician michael howard testified that whoever shot diane and alan johnson at close range on september 2, 2003, would have been hit by a rain of blood spatter. The position and appearance of blood marks on the body and its immediate. The spatters were scanned in a piecewise manner, by cutting the tape joining the poster board sheets. Blood spatter analyzed to determine patterns that give investigators clues to how a crime might have. This interactive site lets you create a dna fingerprint and use it to solve a crime.
The article describes the three classifications of blood spatter velocity and what they mean high, medium, and low, as well as how to tell which way the blood traveled. There are three main sketching techniques that can be used. The characteristics of the blood spatter depends on the force applied to the blood source and the speed at which blood exits the body. Describe how the surface texture of an object affects the shape of individual bloodstains. You will have to determine who is telling the truth and who is lying. For the purposes of teaching blood spatter pattern documentation and analysis without the hazards of human or animal blood, spatter blood was developed to have the same physical characteristics as human blood, such as viscosity, surface tension an. Investigating the reliability of bloodstain pattern analysis. For this system uses analytical model construction based on using images of. Two dimers combine to form the complete haemoglobin molecule. To make an analyst in blood interpretation, one must first understand the basic concepts of blood.
Becausebloodbehavesaccordingtocertainscientificprinciples,trained bloodstainpatternanalystscanexaminethebloodevidenceleftbehindand. Students will list and explain the terms used in analyzing blood spatter evidence. Describe the directly propor tional relationship between stain diameter and dropping height. Blood can be used in two ways as evidence during an investigation. All of this blood spatter and wipes are critical evidence and clues to determining what happened at this crime scene. The scope of this type of evidence includes interpretation of the possible patterns that might be. Bloodstain pattern analysis bpa is the interpretation of bloodstains at a. Mediumvelocity impact spatter highvelocity impact spatter summary references 4 understanding the medium of blood general properties of blood blood makeup the bodys response to breaching of the circulatory system circulatory system considerations reaction of liquid blood to force droplet dynamics in flight droplet dynamics on impact. Identify the mechanisms by which blood spatter patterns are created. The blood spatter patterns tell a story of the crime and help the investigators determine if eyewitness accounts are consistent with the evidence. Blood spatter understanding the clues math cte online. Blood spatter stains occur when blood falls passively due to force being applied to a body. This test method is designed as a procedure for laboratory division personnel to assist investigations where bloodstain patterns occur on physical evidence in a variety of alleged criminal activities.
Blood distribution and spatter uf forensic science online. The web link provides access to the crime scene, the file to download has witnessvictim statements, additional blood evidence, a floor plan of the crime scene, and worksheets to fill out. This course will address the principles of blood spatter creation, and bloodstain interpretation as it pertains to biological evidence and will include processes for the appropriate recording, collection and processing of bloodstains and blood spatter evidence. It also features information on the sam sheppard case the inspiration for the movie the fugitive. Testimony by bevel contradicted the physical evidence in the routier case. The spherical shape is caused by the surface tension of the blood. This document reveals information pertaining to the types of blood spatter which is a potential to be found at a crime scene which involved the spilling of blood. The reader of this document will also be educated on the rationale behind blood and blood spatter by. For this case study your team will be investigating a crime scene involving blood spatter. Bloodstains are ana lysed according to shape, size and distri bution. The document of paleolithic art explains the skills of the early human hunters and shows how they used blood tracks to locate prey. Your team will analyse the blood spatter to try to work out where the victim was located in the room.
Publications national criminal justice reference service. Although research continued into blood spatter patterns in homicide cases, the watershed moment for using blood spatter evidence in american legal cases would not arrive until 1955, when dr. Blood spatter chart geoff forensics for fiction type of pattern type of spatter spatter specifics spatter caused from extra notes low velocity impact spatter passive drips 90 degree circular stain person is actively bleeding or has enough of someone elses blood on himher to drip blood drips can leave a trail indicating bleeders. An expert in blood spatter took the stand monday in the second week of brittany norwoods trial in the killing of her coworker at a bethesda yoga store. Blood is made up of two liquids, plasma and serum, and other solids such as red blood cells, white blood cells, platelets, and proteins. Blood evidence isnt just collected off of weapons, but can also be collected off of the floor or other surfaces in a crime scene. Retired crime lab technician michael howard testified that whoever shot diane and alan johnson at close range on september 2, 2003, would have been hit by a rain of blood spatter.
The scope of this type of evidence includes analysis of the possible patterns that might be observed. Crime scenes andor items of evidence will be examined for potential areas of bloodstain pattern evidence. In the criminal case against david camm, who was tried three times for the murder of his family largely on the basis of blood spatter evidence, both prosecution and the defense used expert bloodstain pattern analysts to interpret the source of the approximately 8 drops of blood on his shirt. If your edpuzzle notes are done, you may addcorrect them. Forensics investigators found blood stains in the family car and concluded that lindy had taken azaria there to cut her throat. By combining source and activity level evidence analyses, a forensic investigator can. Do not use real blood for this lesson as there are several issues that can arise. Pdf journal of forensic studies bloodstain pattern analyst. Paul kirk submitted an affidavit of his findings in the highly publicized case of the state of ohio v. The method seeks to answer the question of how blood travelled through a given space to leave stains on a surface. This is a data set of 61 blood spatter patterns scanned at high resolution, generated by controlled impact events. The zeigler defense team has told me that this morning, judge whitehead has approved statefunding to engage mr paul kish as blood spatter expert in connection with william thomas zeigler s requests for new dna testing.
Feedback on the bloodstain pattern analysis discipline stream. Throughout the case, the local police improperly handled blood spatter and other evidence. Instructor manual, student data sheets for 5 experiments, msds, sixteen general rules of blood spatter, thirty seven investigative terminology terms, blood spatter test, large paper clip, pipets, magnifying glasses, protractors, measuring tape, filter paper, rubber bands, clip boards, clip boards, spray bottles, labels, blood spatter chamber, dowel rods. Additionally, forward spatter will result in a more intense pattern because the majority of the projectile force is concentrated along the vector of the projectile. He will testify to things being scientific fact that are actually uncertain at best, and cannot be scientifically substantiated.
She was later acquitted and exonerated, joining a growing community of americans wrongly convicted with bad science. A simplified guide to bloodstain pattern analysis forensic. The prosecutions experts included tom bevel and rod. Interpretation of bloodstain evidence at the crime. Steven gilbert blood spatter analysis blood spatter analysis is the systematic assessment of the visual patterns of bloodstains at crime scenes based on the physics of fluids brodbeck, 2012, p. Blood evidence blood samples analyzed to determine blood type and dna, which can be matched to possible suspects. It includes both the forward and back spatters for the exit and entrance wounds respectively. The velocity of the blood spatter is a good indication of the speed of the force that sent the blood in motion, suggesting the type of weapon used on the victim. Besides testing, investigators use blood stain patterns to help determine if a crime was committed.
Originsource the place from where the blood spatter came from or originated. Angle of impact the angle at which a blood droplet strikes a surface. Some notes on blood splatter evidence examination and interpretation of bloodstains on and around the body, and of blood spots, splashes and smears at the scene of the crime, are an essential part of a murder investigation. It must be preserved until the analysts from the csi team arrive. Blood forms a spherical shape perfect circular shape. Given three or more stains from drops of simulated blood, students will determine the direction of travel and the angle of impact for each drop. Blood will not break up unless it is acted upon by force. Apr 11, 2011 blood spatter expert appointed in zeigler case. There is a well established though extremely tedious technique by which a specially trained forensic technician can analyse the individual blood spots. Kish is a forensic consultant in corning, new york. Spatter patterns allow investigators to reconstruct what happened at a crime scene. What are the disadvantages of using blood as evidence at a. Varnon has a presentation he gives about the evidence in the case.
For example, bevel testified that because bloodstains on the right shoulder area of darlies nightshirt contained a mixture of darlies blood and each of her two children one stain contained darlies blood mixed with devons and the other contained darlies blood mixed with damons it showed that darlie. More specific subject area, forensics bloodstain pattern analysis bpa. Becausebloodbehavesaccordingtocertainscientificprinciples,trained bloodstainpatternanalystscanexaminethe blood evidence leftbehindand. Demonstrate the ability to combine point area of convergence with impact angle to.
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