Bloodstain pattern analysis is one technique of several in the discipline of forensic science. This technique of using bloodstains as evidences is not new; however, the application of modern science has made bloodstain analysis more and more reliable (Wikipedia). When current technologies and advances within DNA analysis become available to enforcement agencies, the apprehension of criminals and offenders become less problematic (Wikipedia). The forensic science of bloodstain pattern analysis applies scientific knowledge from other disciplines in order to solve a myriad of practical problems.
Bloodstain pattern analysis can draw on biology, chemistry, math, and physics, among others (Wikipedia). When an analyst follows a strict scientific process, this applied science can produce strong, solid evidence (Wikipedia). This is an imperative tool when in the hands of law enforcement. An understanding of bloodstain analysis may allow first responders to a crime scene the know-how in currently collecting and preserving any bloodstain data (Wikipedia). Bloodstain analysts receive specialized training.
The foundation course in bloodstain pattern analysis is the Basic Bloodstain Pattern Analysis Course. This is taught at many government and private institutions. The course criterion was developed by the International Association of Bloodstain Pattern Analysts (IABPA) with the following stated purpose: A course of instruction designed for investigators, crime scene technicians, forensic technicians, and others involved in criminal and medical-legal investigations and crime scene analysis. The course is intended to develop a fundamental knowledge of the discipline of bloodstain pattern analysis.
The course should illustrate to the student basic principals of bloodstain pattern analysis and the practical application of the discipline to actual casework. The course syllabus is not intended to create an “instant” expert. There are three classifications of bloodstains: passive, projected, and transfer/contact. These classifications were developed by the IABPA. Passive stains are developed when the acting force creating it is gravity. A passive pattern is then divided into three sub-categories: passive drop, drip pattern, and flow pattern (IABPA).
Passive drops are created by the force of gravity alone, and the drip pattern is created when blood drips into blood. The flow pattern is a change in shape or direction due to influence of gravity or movement of the object (IABPA). Projected blood patterns are the result of an energy source being transferred through blood. There are several types: low velocity impact spatter (LVIS), medium velocity impact spatter (MVIS), high velocity impact spatter (HVIS), and expiratory blood (IABPA). The three types of velocity impact patterns are caused when an impact at either a low, medium, or high velocity make contact with the blood source (i.
e. medium impact = a battery; high impact = a gunshot). An expiratory pattern 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 (IABPA). A transfer/contact stain is the result of a blood bearing object coming in contact with a non-blood bearing object – thus causing the transfer of blood. Two types of transfer/contact patterns are the wipe and swipe pattern. A wipe bloodstain pattern created when an object moves through an existing stain, removing and/or altering its appearance.
A swipe pattern is the transfer of blood from a moving source onto an unstained surface (IABPA). Blood splatter flight characteristics show that blood tends to form a sphere in flight opposed to the artistic teardrop shape. This is the result in the surface tension that binds the molecules together. This spherical shape is important to the calculation angle of incidence of blood when it hits a surface. This angle is then used to determine the point of origin (PO) – the original area where the blood originated in (Wikipedia).
In 1954, Marilyn Sheppard was bludgeoned to death in her home. Her husband, Dr. Sam Sheppard survived what he called an attack by an intruder. Dr. Sheppard reported that he had been knocked unconscious as he tried to defend his wife (Lyle). Their home was ransacked. Investigators would come to realize that Dr. Sheppard had no blood located on his body nor clothing, and he denied ever cleaning up before the police arrived (Lyle). This troubled the police. The attack was so brutal that the killer would have been covered in blood, and Dr.
Shepard should have had blood transfers located on his body or clothes. Sheppard had no blood located on his hands, which would be impossible because he said he checked for a pulse of his wife’s neck, which was covered in blood. Furthermore, Sheppard claimed that his watch, wallet, ring and keys were missing. This was true. A bag with these items was found no too far from the house; however, they had to traces of blood. Moreover, Sheppard’s pants had no blood on them – impossible is the killer robbed him with bloody hands (Lyle). The watch, however, did have traces of blood.
Theses blood splatters came from flying droplets, indicating that the watch must have been close when the victim was received the fatal blows. If the watch made contact with her neck – as he checked for a pulse – the watch would have blood smears and not droplets (Lyle). Police determined that Dr. Sheppard most likely bludgeoned his wife to death. Then he cleaned himself and trashed the items outside the house were police would find them and made the house look as if it was a burglary (Lyle). Based in large part on the blood evidence, or lack of it, Sheppard was convicted of murder.
After spending ten years in prison, Sheppard was released when the U. S. Supreme Court overturned his conviction. A representative from the coroner’s office stated that the blood located on Sheppard’s watch represented a blood splatter. This means the watch must have present when the blows were struck (Lyle). A renowned criminalist, Dr. Paul Kirk testified that the blood on the watch was a result of Sheppard checking his wife’s pulse. If so, why was the watch found outside the house? This controversy still surrounds the case. In 2004, Nick Berg was horrifically murdered by insurgents in Iraq. His throat was cut and he was decapitated.
His body was found by an Iraqi overpass. The tape was on review on May 11, 2004 for a type of bloodstain analysis. Laura Mansfield, certified in bloodstain analysis by the Laboratory of Forensic Science and is a member of the IABPA, begins her analysis of the footage (Crime Library). It’s reported: “The time displays 13:45:47 in the lower right corner, the victim is pushed onto his left side where his legs are bent at the knees and raised toward his chest and his arms still tied behind his back. At this point, the video becomes out of focus and essentially useless for the purposes of analysis from approximately 90 frames.
As the video comes back into focus, the primary assailant is viewed using the knife to cut the throat of the victim, beginning at the area near his left carotid artery. Almost immediately, blood is seen “pouring” onto the floor (target surface) from the wound caused by the incision (Crime Library). ” There appears to be an edit point. At this point the primary insurgent is no longer holding the knife. “The individual wearing the white hood and previously standing on the right side of the primary assailant is now using the knife in a saw-like manner, holding the knife in (his) right hand while holding the victims hair with (his) left hand.
At 13:47:xx, the individual wearing the white hood ultimately detaches the victim’s head from his body and holds the head outward in (his) left hand, still holding the knife in (his) right (Crime Library). ” The frames that follow appear to jump, at which time the victim’s head is completely detached and the primary object in the frame. Through out the video, time changes frequently from military time back to “regular” time and vice versa.
“Interestingly, the time display on the video changes to 2:46:20 (regular time format) and then switches back to 13:48:45 (military format) while the victim’s head is shown detached from his body in a similar series of frames (Crime Library). ” Bloodstain pattern analysis is an age-old technique, which with new technologies and advancements aid in the capture and prosecution of criminals. This analysis procedure is used in many different ways and draw upon a myriad of disciplines. In result of a strict process, bloodstain pattern analysis will prove solid, concrete evidence and is a useful tool in the hands of law enforcement.
References IABPA (International Association of Bloodstain Pattern Analysts). Suggested IABPA Terminology List. Date visited 8 April 2006. http://www. iabpa. org/Terminology. pdf Lyle, D. P. , MD. Uncovering the Evidence: Those Messy Bloodstains. Forensics for Dummies. John Wiley & Sons Inc. p. 98 Nick Berg Tape. Crime Library. Court Tv. Date visited 8 April 2006. http://www. crimelibrary. com/about/authors/mansfield/ Wikipedia Online. Bloodstain Pattern Analysis. Date visited 9 April 2006. http://en. wikipedia. org/wiki/Bloodstain_pattern_analysis