Introduction
Bloodstain pattern analysis (BPA) is a subspecialty of forensic sciences, dealing with the analysis and interpretation of bloodstain patterns in crime scenes. The aim of BPA is uncovering new information about the actions that took place in a crime scene, potentially leading to a confirmation or refutation of a suspect's statement. A typical goal of BPA is to estimate the flight paths for a set of stains, followed by a directional analysis in order to estimate the area of origin for the stains. The traditional approach, referred to as stringing, consists of attaching a piece of string to each stain.
A correct distinction between bloodstain patterns formed by ‘‘contact transfer’and‘‘spatter’’ can be essential for the accurate
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Blood and the stain patterns created during these acts of violence are of particular interest to the forensic examiner. Bloodstains are routinely utilized to make critical forensic links between victim(s), suspect(s), physical evidence, and the crime scene. To assess the entire forensic value of a bloodstain, the stain must be located, and the physical characteristics of the individual stains that make up the overall pattern must be visualized in a nondestructive manner. Merely locating bloodstains on a garment is sufficient for DNA testing, but to fully understand the entire value of the stain patterns, there must be an ability to visualize the physical characteristics associated with the stain: stain size, shape, distribution, location, overall physical appearance, as well as the interrelationship between the bloodstain and the substrates on which they are located. A bloodstain pattern analyst will evaluate physical characteristics to determine what type(s) of mechanism(s) could account for a specific pattern. This pattern analysis can then be incorporated with other related forensic findings to reconstruct the events surrounding the blood-shedding …show more content…
A 50W Quartz Tungsten Halogen (QTH) white light source was used for sample illumination. We can use ChemImage Xpert software for the instrumentation during data collection. Because of the strongly absorbing nature of the denim fabric, a longer exposure time was required to achieve a suitable signal, as compared with the T-shirt sample. Because the bloodstain pattern on the denim sample could not be resolved using the NIR region of the spectrum, a short-wave infrared (SWIR) CONDOR Hyperspectral Imaging System (960-1650nm) was also used to collected NIR range would yield greater contrast. As with the NIR CONDOR, a QTH white light lamp was utilized for sample illumination. The experiment parameters for both NIR and SWIR data collection are listed in Table
One of the most important purposes of physical evidence is to establish the identity of a suspect or victim. Some of the most valuable clues at a crime scene are fingerprints. "Processing a crime scene" is a long, tedious process that involves focused documentation of the conditions at the scene and the collection of any physical evidence that could possibly shed light on what happened and point to who did it.
The world of Forensic Scientist is an amazing and fascinating place. There are so many aspects that go into forensic science but in this paper we are only covering bloodstain spatter patterns. Bloodstain spatter patterns are not solely used to solve crimes but I do feel it is one of the most important. Bloodstains never lie.
The understanding of blood spatter patterns is not a widely recognized forensic practice. Bloodstain pattern interpretation (BPI) is commonly used in murder investigations, but could be utilized in everything from simple assault to mass murders if the number of trained professionals increased. BPI can reveal critical information into reinventing a given crime scene. Everything from the number of blows, stabs or shots a victim was given, the movement that was undergone by the victim and assailant after bloodshed began, position of objects at the crime scene and the type of weapon, if any, that was used can be uncovered.
The goal of this experiment is to determine the blood types of the samples given and to learn what interactions occurred to each blood type. Determining an individual’s blood type and how it reacts with Anti A, Anti-B, and Anti Rh serums played a crucial part in this experiment. The researcher concluded that agglutination (clumping) occurred in some of the blood samples. For example, Mr. Smith’s blood reacted with Anti-A and Anti-Rh serums (antibodies) allowing the researcher to determine the blood type is A. Mr. Jones’s blood reacted with Anti-B serum but it did not react to Anti-A or Anti Rh allowing the researcher to believe that the blood type is B. Mr. Green’s blood reacted with all serums and caused a reaction to occur resulting the blood type to be AB positive. Mr. Green’s blood also had a positive marker for Rh factor. However, Ms. Brown’s blood had no reaction at all and the researcher determined if no reaction occurred then the sample had no antigens but proved to have some antibodies, resulting in blood type to be O. The purpose of this experiment is to determine whose blood has type A, B, AB, or O.
Introduction: One summer morning, a 38-year-old woman named Anna Garcia was found dead. Anna was found lying facedown in the entry hallway of her home in a pool of blood. Many different pieces of evidence found at the crime scene have been analyzed to determine the manner of Anna’s death: natural, accident, or homicide. The analyzed evidence found at the crime scene includes fingerprints, blood type, shoeprint, hair, unknown substances, blood spatters, and DNA. Anna Garcia’s autopsy report currently contains information on Anna’s toxicology results, external examination results, and physical examination results. The evidence that has been analyzed mainly focuses on the persons of interest: Alex Garcia, Doug Greene, Erica Piedmont, and Lucy
Blood spatter analysts are a crucial part of a homicide investigation. They examine the blood stains left behind at a crime scene with the help of criminal investigators. They try to find a pattern or trail with the blood to figure out what happened at the crime scene. These blood patterns can show where the victim was hit, how they were hit, if they struggled, and what kind of weapon the killer used. They use many techniques to collect evidence that can be analyzed at the lab. Common techniques are measuring the diameter of the blood drop, measuring the spatter zone, and taking pictures. Many analysts try to act out the homicide scene to piece together the crime scene and figure out what happened. They also sketch out the scene to go along
he Blood Spatter Analyst (also known as "Bloodstain Pattern Analyst") uses many techniques to collect and analze blood that has been left behind at a crime scene. They uses swabs and ultraviolet light, as well as photgraphy to collect and analyze trace evidence and recreate spatters. After analyzation of the spatter, they can determine what weapon was used, which direction the suspect or victim went, the number of wounds the victim suffered, the trajectry of a projectile, and what occured during a violent crime.
The wet blood should be transferred onto clean cotton cloth. Bloodstained cotton cloth must be allowed to air dry before packaging in a paper container. Each object and container must be properly labeled. Dried bloodstains on weapons, for example, should be collected separately by collecting the entire item. Each item should be placed in its own paper container, and these should be sealed and labeled properly. The bloodstain pattern should be documented and sketched to the extent necessary. The stain can be tape lifted or scraped off the object onto a clean piece of paper. The tape lifter or the paper with blood can then be placed into a druggist fold, and placed in an envelope which is sealed. Each item must be labeled
The topic for science fair is on blood spatter. If terminal velocity and height van affect the radius of a blood spatter print. To figure out whether after a blood splatter reaches terminal velocity and it starts to slow down will the radius start to become decrease. In this experiment the independent variable is the height the blood is dropped from, and the dependent is the radius of the blood spatter. Independent and dependent variables: The independent variable is the amount of sugar in each solution and the dependent variable is the levels of vitamin C the solution has.
Bloodstain pattern analysis (BPA), known in the criminal justice field as blood splatter analysis, has been studied since the 1890s. Blood splatter, or bloodstain pattern constructional readings, is a technique that seeks to piece together the incident that caused an individual’s bleeding. Understanding blood splatter on a wall or various surfaces can be instrumental in formulating if a crime was committed and if the blood discovered at the crime scene can be used as evidence. The first documentation of blood splatter research occurred at the Institute for Forensic Medicine in Poland, by Dr. Eduard Piotrowski . During Dr. Piotrowski’s research and documentation period, where he used live bunnies to research blood splatter from head
There are different types of patterns that blood splatter makes. It can be a drop, a messy splatter, to just a little pool of blood it all just depends on what caused it to happen. Forensics and law enforcement officers can determine what kind of object was used in a murder case based on the blood splatter pattern.
Have you ever wondered how much a single blood splatter could impact a whole crime scene? In January 2004, Sachs and Jessica Snyder wrote an article titled, Blood is the Ink, Crime is the Story, which could be found in “Popular Science”. Blood spatter tells more of a story than most individuals know, including detectives and crime-scene analysis. A blood stained analysts, Paulette Sutton, informs those who do investigate crime how important a single blood stain is. An average everyday person could easily tell which direction the blood stain came from, and what height it had fallen from, nevertheless there is still more to the story.
Forensic science is a key aspect of Criminal Justice that helps rid the streets of lunatics and murderers. One of the most important fields of forensic science is blood spatter analysis. Under the Crime Scene Investigation, analysts gather the information that could eventually lead to a victim’s killer. Basic and complex information can be found when analyzing blood. We can learn what kind of weapon was used, the time of death of a victim and other important facts that can help a case. The pattern that the blood gives off give forensic scientists the tools that they need to help solve cases.
The book gives a general overview of the field of forensic science. The sections of the book include “The Scene of the Crime; Working the Scene--The Evidence; Working the Scene of the Body Human;
Moving forward to questions of blood spatter interpretation, historically a subjective area of practice, the work of Trombka et al. (2002) sheds important light on how computerized analysis can now lead to the automation of many elements of blood spatter analysis. This is incredibly beneficial, for this particular CSI technique, because of the fact that computerized analysis brings about the type of parsimony, associated with rigorous hard sciences, which increases a discipline’s credibility in a court-of-law. Indeed, and because computerized spatter analysis will inevitably bring about greater reliability in spatter analysis, inasmuch as cases will now be analyzed in identical ways by different analysts, the discipline’s probative relevance to court cases is likely to be increased dramatically.