Criminalistics Blood Spatter Analysis, Research Paper Example
Words: 2808Research Paper
This paper deals with the definition of Serology and Forensic Serology in particular and the benefits Forensic Science can gain from blood spatter /pattern analyses in solving crimes from laboratory analyses.
Discussions regarding the characteristics of blood, its components, behaviors on different surfaces, as well as how the spatter analysis can aid in the direction of blood flow, the weapons used, and in the re-construction of crimes committed.
Laboratory Analyses such as the presumptive test, Luminol, fluorescence, LCO and precipitin are described in an effort to show how Serology procedure relate to Forensic Science and the ultimate capture and conviction of criminals.
The paper also showed the importance of evidence collection, chain of custody, and lab organization and utilization of experts are used to ensure effectiveness and reliability in results gained from analyses of blood spatter analysis.
Threats from the emergence of DNA have been highlighted as well as the reasons why Forensic Serology and in particular serology procedures will remain on the scientific landscape well into the future were adequately covered
Serology: Blood Spatter /Pattern Analysis
How Serology relates to Forensic Analysis, the benefit of it to crime laboratory, and the effectiveness and reliability to determine different aspects of crime?
Serology, according to Medline Plus (2011) is blood testing to detect the presence of antibodies against microorganism, as certain microorganisms stimulate the human body to produce antibodies to fight off active infections.
Forensic Serology on the other hand is the process of determining the type and characteristics of blood, blood stain examination and the preparation of testimony or presentations at trials, according to Forensic Medicine Information (2011). The discipline also includes the analysis of semen, saliva and other body fluids that may or may not involve DNA.
Forensic Serology, according to Gaensslen (2000), has traditionally been concerned with the identification and individualization of biological evidence, using methodology from biochemistry, immunology, histology, microscopy, and serology for those purposes. However, according to Gaensslen (2000), the emergence of DNA typing has led to a supplanting of the use of classical serological and biological markers for evidence individualization, although many forensic laboratories, because of the connections between forensic serology and criminalistics in apprehending criminals have maintained the traditional approach.
Blood according to Forensic Medicine Information (2011), is the most common and perhaps well know and most important evidence in the criminal justice system today, and since there are no substitute for medical and forensic purposes, an understanding how serology and blood spatter analysis in particular, relates to forensic serology demands basis comprehension.
This should involve the behavioral characteristics blood as a liquid, which is often foundat crime scenes and has to be analyzed to ascertain certain key information that will provide clues to help investigators capture and prosecute suspected criminals.
Blood, according to Kendal/Hunt Publishing Company (2011) is made up of red blood cells or erythrocytes, white blood cells or leukocytes, plasma and platelets or thrombocytes. Red Blood Cells is the most abundant cells in the blood and contain hemoglobin which is an oxygen carrier and is manufactured in the bone marrow, while white blood cells forms part of the immune system and destroys infection agents described as pathogens (Kendal/Hunt Publishing Company, 2011).
Blood Plasma is the yellowish portion of the blood which contains electrolytes, nutrients and vitamins, clotting factors, hormones, and proteins such as antibodies to fight infections, while platelets, which are clotting factors transported within the plasma and clots together by coagulation to prevent further blood loss by sealing off the area where wounds has occurred, according to Kendal/Hunt Publishing Company, 2011).
Blood or blood stains at the scene of a crime provoke questions like is it blood, is it human blood, how does it relate to the crime committed, and if so whose blood is it? These questions in the minds of crime investigators can be answered by Forensic Scientists working individually in specific areas, once the crime scene is properly protected and they are able to gather the evidence.
According to Kendall/Hunt Publishing Company (2011), Forensic Scientist will carry out tests to determine the blood types, alcohol content, the presence or absence of drugs, and the process whereby blood and blood stains may have been deposited on the spots where they were found.
Blood Spatter/Pattern provides evidence to forensic scientist on the basis of the different patterns that emerge after various forces may have been applied by assailants to cause blood to be spilled on different surfaces and the impact of these surfaces on its physical properties, according to Kendal/Hunt Publishing Company (2011).
Forensic Scientist knows, on the basis of their training that blood obeys the laws of physics and possesses certain characteristics such as, (a)its droplets remain spherical in shape when in collision with surfaces, (b)on impacting with surfaces stains are left behind, and (c) droplets that falls from the same height will hit surfaces at the same angle and generate the same shape and size stains, according to Kendal/Hunt Publishing Company (2011).
This knowledge will help to guide forensic scientist investigating blood spatter evidence at crime scenes, to provide largely irrefutable evidence to crime investigators regarding how certain crimes were committed.
Blood stains at a crime scene facilitate a blood pattern analysis which enable the type and velocity of the weapons used to be known, the number of blows, whether the assailant or assailants were right or left hand, the position and movements of both victim and assailant during the crime, the order in which the wounds inflicted, types of injuries, timeline of the crime and the time of death, according to Kendal/Hunt Publishing Company (2011).
Blood Spatter and pattern analysis benefit forensic analyses in crime laboratories by facilitating crime scene reconstructions, which entails utilization and connection of stain conditions, the patterns of blood, distribution locations and directionalitiesfor different crimes, according to Lee & O’Neil (2002).
Crime investigators, after reconstructing crime scenes can then conduct genetic marker typing, age determinations for both victim and assailant, source determinations and race and sex determinations, so that a more comprehensive pictures of entire crimes can become available and provide leads that can be pursued with immediacy for the eventual capture and trial of suspects, according to Lee &O’Neil (2002).
In terms of the reliability and effectiveness of blood spatter/pattern analyses to forensic serology with different aspects of crimes, forensic scientists can utilize areas of intersection and convergence principles with great precision to determine the locations of blood sources and the spots were blows had been inflicted , according to Lee & O’Neil (2002).
Blood sources can be determined by drawing line from various blood spots droplets to a focal point where they all intersect, while the spots where the blows have occurred or the area of convergence can be established at the scenes of different crimes by measuring the angles with the use of strings, according to Lee &O’Neil (2002).
According to Lee &O’Neil (2002), the behavior of the blood stain patterns at the scene of different crimes are also reflective of the surfaces on which these crimes have been committed, and the results obtained can accurately and reliable predict the mode of operations with respect to each event. The harder and less porous the surfaces the scientists asserts, the less blood drops will break apart, while on the softer more porous surfaces, more blood drops will break apart and the pointed ends of the blood stains will face the directions from which they have travelled (Lee & O’Neil, 2002).
Additionally, activities on the crime scene like transfer, swipe and wipe can be detected as they relate to blood splatter on the surfaces and what the assailants had done to their victims, and can be analyzed to give investigators more detailed information on the crime, especially regarding the motive, time and opportunity according to Lee & O’Neil ( 2002).
Blood transfer activities, when detected, enables images to be identified, recognized and be related to particular objects that are applied in the commission of the crimes, while swipes technique determines whether blood was previously in areas that have been scrupulously cleaned. In comparison wipe technique detects whether assailants were engage in moving non-blood bearing objects through wet blood stained areas and cause alterations in the original blood splatter/patterns, according to Lee & O’Neil ( 2002).
These observations at different crime scenes, will effective provide reliable clues to crime investigators as to what had transpired during and after the crimes that have been committed.
The relevance of blood splatter analysis in forensic serology, to the solving of crimes is without question when examinations are taken of the chemical tests that are done to blood evidence observed at different crime scenes. These include using powerful light sources, blood reagent test, flourescen, luminal, the leuco crystal violet or LCV test, precipitin and the DNA which determine class evidence including blood type (Kendal/Hunt Publishing Company (2011).
The application of high intensity light or UV light, according to Kendal/Hunt Publishing Company (2011) to crime scenes, will enable forensic scientists to know immediately whether traces of blood or other body fluids are present and can be extracted for analysis in the crime laboratory. Without this test many criminals would escape punishments for the various possible vicious crimes they have committed.
Presumptive test are also applied, according to Lee & O’Neil ( 2002), to detect the presence of blood and in particular the presence of the hemoglobin, which if present and tested with the Kastle-Meyer procedure, produces characteristic pink colors which strongly indicate to forensic scientists that crimes has been committed and had been altered to deceive the law enforcement officers.
Experts in Forensic Science on visiting crime scenes armed with Hemastrips, can apply them to suspected blood spots which may be invisible to the naked eye, but when green color or blue green colorations are immediately observed, will serve to reliable inform them and their rest of the investigating teams of the presence of blood on those crime scenes, according to Lee & O’Neil (2002).
Luminol analytical applications despite limitations, serves forensic science well also on crime scenes that have been doctored, in that on application they reactions with traces of blood produces blue luminescence to confirm the existence and provide indications that further analysis should be conducted to unearth more details according to Lee & O’Neil (2002).
According to NIJ Journal (2003), new and improved techniques for detecting and distinguishing trace evidence, even minute quantities of materials such as blood, chemicals, fibers, glass, hair, plant materials or plastics, and are gradually becoming a part of the arsenal of law enforcement in their pursuit of criminals
Luminol when sprayed, according to NIJ Journal (2008)has a number of limitations which investigators have to confront, and these include the production of a faint glow that negatively affects the photographing of the evidence. Investigators in such cases have to wait for dark or create their own environment to maximize the use of the technique.
The reagent also emits false reactions that will lead to the loss of genetic markers as well as being expensive and cumbersome at very large crime scenes, but certainly provide information that can be used with those of other test to fine tune the work of forensic scientists (NIJ Journal, 2003)
Crime scene investigators according to Jacoby (2008), widely use fluorescent –type dyes to search for trace residues of blood, due to the credible and reliable and consistent oxidation reactions that occur between the dye molecules and blood or other biomaterials to produce fluorescent forms. These forms according to Jacoby (2008), shows their colors when the samples are irradiated by suitable light sources.
Fluorescent then, according to Jacoby (2008), provides evidence to law enforcement, but they have very limited time frame to extract them due to the short shelf life of the technique.
LCV, according to Lee & O’Neil (2002), when applied after presumptive tests, can help to reveal tangible evidence of blood spots that can be photographed and taken to forensic laboratories to be examined.
Precipitin test critically determines whether the blood stains identified on crime scenes originate from human or some other forms of animals, due to the antiserum present reacting with the human proteins that may be embedded within the stains identified, according to Lee & O’Neil (2002).
Blood type identification, according to Innes (2000)can be of great practical importance in ensuring the effectiveness and reliability of forensic science on blood spatter evidence observed at crime scenes. Analysis that identifies the blood types of victims on the clothing of assailants will add weight to prosecutor’s presentation of evidence, especially when the analyses are supplemented with the use of electrophoresis to detect the presence of specific enzymes and proteins in these blood stains under examination.
Electrophoresis, according to Innes (2000), involves the soaking cotton thread in samples of samples which in this case is blood from crime a crime scene or from the clothing of assailants and soaking the into gel coating glass plate, then applying weak direct electric current so that the different components of the blood could be transmitted along the path of the thread at different rates base on their molecular weights. Application of specific reagents on these different components will provide accurate evidence of the specific compositions of the blood evidence found, especially as it relates to the interactions between assailants and victims (Innes, 2000).
One of the major reasons for effectiveness and reliability of forensic serology in solving crimes for different types of crimes and ensure the public protected from criminals as well as innocent people not being unjustly punished, according to Chemistry Explained (2011), is that forensic scientist performed specialized analysis to indentify materials and learn from the nature of such evidence, especially after consultations with the highly specialized group of experts.
However, according to Chemistry Explained (2011), the foundation for such effectiveness and reliability is principally the methodology of evidence collection. The physical evidence collected at crimes scenes are sealed in specialized containers to prevent contamination and degradation, before being carefully catalogued.
Chemistry Explained (2011), went further to explain that chains of custodies are established and documented as the evidence are sent to the forensic laboratories. Operationally, the organization in the forensic laboratory adds to the accuracy and reliability of the results achieved and sent to the crime investigators, and according to Chemistry Explained (2011), the evidence on arrival in the forensic laboratories are examined by specialized teams of forensic experts in areas such as body fluids, forensic pathology, firearms test and classifications, explosives, chemical composition and classification of materials.
These composite tests and analyses will help ensure that information communicated to make cases against accused criminally charged with committing crimes and has left blood evidence at crime scenes be successfully prosecuted.
Serology also plays a key role along with DNA testing, to provide reliable results to Child Support Administration in their efforts to find and bring into conformance dead beat fathers, who are denying that they are responsible for fathering children across the country. When blood samples, saliva, semen and other body fluids are collected and subjected to electrophoresis, according to Chemistry Explained (2011), and then to enzymatic analysis, specific and accurate results will be produced to confirm or deny the validity or arguments that had been presented to the courts, and ensure justice hasbeen served.
The argument of Gefrides and Wech (2011) could be taken as conclusive, regarding the effectiveness and reliability of serology procedure at different crime scenes. They remark that serology procedures have been employed for most of the twentieth century and the technique have remained essentially the same even today. The consistency of application of serology procedures as it relates to blood splatter/patterns and the results it has produced will cause the use of the technology to continue well into the foreseeable future, despite developments in science and technology in other areas.
The DNA revolution have caused the abandonment of traditional genetic markings, but the importance of forensic serology, because of its effectiveness and reliability concerning the treatment of forensic biological evidence, has remained on the landscape and continued in use, according to Gaensslen (2000).
Blood and physiological fluid stains still requires credible and reliable identification according to Gaensslen (2000), and the characteristics of blood spatter/pattern analysis and its association with criminalistics remains as strong as ever, and seems to have the perpetual support of crime fighters in the industry, especially when it comes to find clues that inextricable links criminals to crime scenes.
Chemistry Explained (2011). Forensic Chemistry Foundations and Applications www.chemistryexplained,com/fe-ge/forensic-chemistry.html , 11.24/22
Forensic Medicine Information (2011). Forensic Serology www.forensic-medicine.info/forensic-serology.html, 11/24/11
Gaensslen, R.E. (2000).Forensic Analysis of Biological Evidence Forensic Science Vol. 1 Release 29 June 2000 www.sjsu.,edu/people/steven.lee/courses/c2/sk/wecht29.pdf , 11/24/11
Gefrides, L. & Wech, K. (2011). Forensic Biology: Serology and DNA Chapter 2 www.media.axom.es/pdf/83320_2.pdf , 11/25/11
Innes, B. (2000). Bodies of Evidence Readers Digest Pleasantville NY
Jacoby, M. (2008). Clues at the scene of a crime Chemical Engineering News Vol. 86 No. 12 pp.59-60www.pubs.acs.org/cen/coverstory/86/8612cover3.html , 11/25/11
Kendal/Hutch Publishing Company (2011). Blood Evidence Chapter 11 www.newportsd.org 11/24/11
Lee, H.C & O’Neil, T.W. (2002). Cracking Cases Prometheus Books Amherst, NY.
Medline Plus (2011). Serology Medline Plus Medical Encyclopedia www.nim.nih.gov/medlineplus/ency/article003511.htm , 11/24/11
NIJ Journal (2003). Without a Trace? Advances in Detecting Trace Evidence Issue No.294 July 2003 www.ncjrs.gov/pdffiles1/jr0002496.pdf , 11/24/11
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