107th SEMI-ANNUAL SEMINAR (Spring 2006)
CALIFORNIA ASSOCIATION OF CRIMINALISTS and
FORENSIC SCIENCE SOCIETY JOINT MEETING
May 8-12, 2006
THE MIDDLE YEARS: CRIMINALISTICS 1949-1979
Duayne J. Dillon, Dcrim
A brief review of the Berkeley Criminalistics Program, and three California Criminalistics Laboratories. Included will be the presenter's impressions of the academic program and observations the laboratories' organizations, staffing and technology. The presentation will include period photographs.
TECHNOLOGICAL ADVANCES IN CRIMINALISTICS ACCOMPANIED BY SCIENTIFIC VACUUMS
Peter DeForest, PhD, John Jay College / CUNY New York
Since I began my career in criminalistics in 1960, I have witnessed extensive and profound changes in the field. The most patently recognizable of these have been in the areas of growth and technological advances. For the most part these changes have had a positive impact on the field. My main concern in this paper will be some less visible changes that I view as negative. In a real sense, the potential contributions of the positive developments have been offset to a significant degree by these other factors. By any measure, growth whether specified in terms of numbers of laboratories, laboratory size, or number of scientists employed as criminalists, has been striking. As alluded to above, there have been some negative consequences of the rapid and sustained growth of the field of criminalistics over time. For one, the demand for forensic laboratory services has outstripped the increased capability derived from the funding gains attributable to growth. Criminalistics laboratories remain under-resourced. Training and mentoring have also suffered as a consequence of growth. Advances in technology have provided a succession of powerful new tools for use by the criminalist. These tools have greatly improved the quality and quantity of information derived from the analysis of many items of evidence. However, again, there have been important unintended negative consequences, which remain largely hidden to those outside the field and, unfortunately, to some within the field as well. With the powerful capabilities that our tools provide, it is easy to lose sight of the fact that there is often more to case solutions than the compilation of analytical data on individual items of evidence. For each investigation greater emphasis needs to be placed on recognizing all of the relevant physical evidence and in developing a scientific understanding the information latent in it. Steps need to be taken to develop a wider recognition of the problem. Strategies are necessary to bring about the needed changes. Possible steps and strategies to accomplish these goals will be discussed. Illustrative case examples will be used as time allows
BORESCOPES FOR FORENSIC APPLICATIONS-UNDERSTANDING THE OPTICS
Ken Harrington, Gradient Lens Corporation, Technical Advisor to Association of Firearms and Toolmarks Examiners
Optics: Rigid vs. flexible, resolution, contrast, alternative optical designs, diameter, length, field of view, magnification, direction of view, prisms vs. mirrors, articulation, lighting, and image documentation. Images: Sample "thru-the-borescope" images of firearms, cartridge cases, a sabotaged barrel, and of bullets lodged in a wall. .
R -V - PALMER: A VICTORIAN POISONING CASE WITH LESSONS FOR THE 21ST CENTURY
A Robert W Forrest, Consultant in Clinical Chemistry & Forensic Toxicology, Sheffield teaching Hospitals Foundation NHS Trust & Professor of Forensic Chemistry University of Sheffield
Alfred Swaine Taylor was born 200 years ago in 1806. He was arguably the most distinguished English Toxicologist of the 19th Century. (I say English, rather than British, for the Scots could make a convincing case for the primacy of Christison in the hierarchy of British Toxicologists). R -v- Palmer, was possibly his most important case. It still has relevance today. Dr William Palmer was member of the Royal College of Surgeons providing general medical services in the Staffordshire market town of Rugeley where he had been born in 1824. Like many modern doctors and nurses who come before the Courts on homicide charges he had had some difficulties as a student. Nonetheless, he had become a popular and reasonably successful practitioner in his home town, with a particular reputation as a bonesetter. He developed a taste for the life of the turf, and by the time of his trial he had virtually given up his medical practice to concentrate on training his string of horses. Dept, not surprisingly, became a problem. He used his knowledge of the pharmacopoeia to address these problems. Amongst his victims are thought to have been his wife, his mother-in-law, a brother, an illegitimate child, a mistress and, finally, a debtor. His last victim, John Parsons Cook, died of a short illness characterised by episodes of vomiting and tetanic spasms, the latter occurring after the administration of medicines to which Palmer had access. The investigation of Cook's death had some interesting features:
- The autopsy was done by a medical student.
- There appeared to have been interference with the viscera en route from the autopsy to Dr Taylor.
- There was interference with letters from Dr. Taylor to the Coroner.
- Palmer attempted to suborn the coroner.
- The toxicology analyses showed no significant positive findings. In particular, no strychnine was found in Cook's viscera.
- An Act of Parliament was passed, the Trial of Offences Act 1856, to allow Palmer to be tried at the Old Bailey in London rather than before a prejudiced Staffordshire jury.
- Journalists used subterfuge to obtain interviews with Dr. Taylor, the information obtained being used in his cross examination.
Despite all this, Palmer was found guilty and sentenced to death. In my presentation of this case I will highlight the lessons of special relevance to those giving expert evidence to contemporary Courts.
COVERT VIDEO SURVEILLANCE OF MUNCHAUSEN SYNDROME BY PROXY
Beatrice Yorker, JD, RN, MS, FAAN, Dean, College of Health and Human Services California State University, Los Angeles
Hospitals in the United States, Britain, Australia, and Canada have used covert video surveillance (CVS) in hospitals as a means of documenting Munchausen syndrome by Proxy, or fabrication of symptoms in children. Hall, Eubanks, Meyazhagan, et al. (2000) published a study evaluating the use of covert video surveillance in diagnosing Munchausen Syndrome by Proxy (MSBP). They concluded that the standard of care in pediatrics should include the capability of CVS as a diagnostic tool. This session will review the Fourth Amendment and Title III as they relate to the right to privacy and this form of evidence collection. The current controversy surrounding MSBP has caused the profession of child protection to change strategies and diagnostic labels in order to intervene in these cases. Strategies for addressing the backlash and ethical issues will be discussed. Actual footage of covert video surveillance will be shown, with discussion of best practices for implementing CVS in a hospital setting. Use of video footage for confrontation, evidence in court, and then ultimately in follow up therapy with the perpetrator will be discussed. Other forms of evidence collection, such as toxicology, eye witness accounts, and indirect evidence such as improvement of the child's condition upon separation from the primary caregiver will be reviewed. The presenter is a psychiatric nurse and an attorney who has testified in several complex cases including termination of parental rights involving video taped footage of injection of fecal material into a child's intravenous line, and cases in which there was no video tape footage, but direct and circumstantial evidence resulted in successful child protection. Her expert testimony was upheld on appeal by the Supreme Court of Georgia In the Interest of C.M. and M.M., Children. 236 Ga. App. 874, 513 S.E. 2d 773 (1999).
Hall, D. E., Eubanks, L., Meyyazhagan, S., Kenney, R. D., Johnson, S. C. (2000) Evaluation of covert video surveillance in the diagnosis of Munchausen Syndrome by Proxy: Lessons from 41 Cases. Pediatrics 105(6):1305-1312.
Samuels, M. P. & Southall D.P. (1992) Munchausen Syndrome by Proxy. British Journal of Hospital Medicine 47:759-760.
Yorker, B.C., (1995) Covert Video Surveillance of Munchausen Syndrome by Proxy: The Exigent Circumstance Exception. Health Matrix: Journal of Law-Medicine 5(2): 325-346.
"MAD, BAD AND DANGEROUS TO KNOW": HEALTH CARE PROFESSIONALS WHO MURDER THEIR PATIENTS.
A Robert W Forrest, Consultant in Clinical Chemistry & Forensic Toxicology, Sheffield teaching Hospitals Foundation NHS Trust & Professor of Forensic Chemistry University of Sheffield
Beatrice Yorker, JD, RN, MS, FAAN
The presenters, a physician and nurse from the United States and United Kingdom, both with law degrees in addition to their professional qualifications, will present, and draw conclusions from, a number of cases from their respective countries where health care professionals have been prosecuted for the murder of patients in their care.
These cases are relatively uncommon, at least in comparison to other types of homicide. However, one concern is that in most detected cases, a number of deaths occur before suspicions are aroused. The typical case involves an increased number of cardiopulmonary arrests on a particular unit that are ultimately linked to presence of a specific nurse or healthcare provider. The investigation of such cases can be very resource intensive and the high intelligence of the suspects makes careful planning of their interview mandatory. Downstream monitoring of the interview by an appropriate healthcare professional can be invaluable as can the incorporation into the investigative team of police officers with nursing or other healthcare qualifications. The defense will usually be competent and well funded; extra-curial factors, whether or not introduced deliberately by the defense, will have to be anticipated by the prosecution team. Video footage of some of the convicted nurses will be provided. Many perpetrators have a history of academic and disciplinary problems either as students or at earlier stages in their career. A more pro-active approach to students and practitioners with such problems, with career long monitoring of those who remain in a healthcare profession may be justified. Such individuals are rarely mad, often bad (sociopathic), and may claim to be driven by idealism. For patients they are always dangerous to know.
FIRE DEBRIS ANALYSIS - A BRIEF RETROSPECTION
Boyd E. Lasater, F-ABC, California Department of Justice - Sacramento Laboratory
This presentation is a brief retrospection of some of the methods used in the discipline of fire debris analysis. It is intended to be at an introductory level; therefore no prior arson tendencies are required. The starting point of this overview will be the separation technique of steam distillation. The resulting sample was characterized by certain physical properties such as flash point, specific gravity, and refractive index. From this starting point, technical advances in both the separation techniques and analytical procedures will be introduced, culminating in the current carbon strip methods of extraction and gas chromatography/ mass spectrometry ion profiling analysis.
AN INTRODUCTION TO THE IGNITABLE LIQUIDS REFERENCE COLLECTION AND DATABASE
Bradley D. Cooper, Bureau of Alcohol, Tobacco, Firearms and Explosives
The Ignitable Liquids Reference Collection and Database is administered by the National Center for Forensic Science and is available to fire debris chemists nationwide to assist them in the identification of ignitable liquid residues. The National Center for Forensic Science provides research, education, training and other resources to the forensic science and criminal justice communities. The NCFS is a National Institute of Justice program that is hosted by the University of Central Florida. The database is available online while ignitable liquid standards from the reference collection may be purchased for a nominal fee. The presentation will discuss the Ignitable Liquids Reference Collection and Database as an available resource to fire debris chemists.
"DO MY EYES DECEIVE ME" THE PSYCHOLOGY OF CRIME SCENE ASSESSMENT AND INTERPRETATION.
Callum Sutherland, Det Sgt Metropolitan Police, Council Member Forensic Science Society
It is widely recognised in criminal investigation that the forensic science process often begins at a crime scene itself. However, prior to the collection of physical evidence it is of the utmost importance that the detective investigator, crime scene manager and or scientist, where appropriate, determine how the physical evidence was created and in doing so reconstructs how the crime scene came to exist. Crime scene interpretation and assessment is largely based on experience, logic and an understanding of our world of crime as we see it. If a crime scene is misdiagnosed at the outset, the scene examination and criminal investigation that follows is at risk. Crime scene assessment, interpretation and reconstruction are an on going process throughout an enquiry and must be completed in an organised, methodical, systematic and logical manner. It involves perception and our ability to correctly analyse what we see and in turn develop and gather the correct information and intelligence from the scene itself. When coupled with a systematic study of related information such as scientific scene analysis, interpretation of scene pattern evidence, laboratory examination of physical evidence and a systematic study of related information, scene assessment and interpretation will assist in the formulation of a crime scene theory based on logic. When undertaken in a rigorous, objective and professional manner, crime scene assessment will be highly influential on the development of subsequent effective major lines of enquiry.
PART 1: BULLET HOLES IN WOOD: WHAT CAN BE DETERMINED FROM THEM?
PART 2: THE LINCOLN TARGET BOARD
Lucien C. Haag, Forensic Science Services
In August of 1863 Christopher Spencer had a private meeting with President Abraham Lincoln where he presented his revolutionary 7-shot repeating rifle to the President. The next day Lincoln fired a full magazine at an improvised target fashioned from a pine board. The board was placed against a tree in an area near the present-day Washington Monument. Lincoln was so impressed with the Spencer that he personally endorsing it and set aside General Ripley's opposition to the purchase of repeating cartridge guns for the Union Army. The Spencer rifles and carbines became the most dreaded and hated gun by the Confederates who fought the entire war with single shot muzzle-loading rifles and muskets. Spencer retained the target board for many years then sent it to the State of Illinois where it purportedly was lost in the mist of time. The Lincoln Target Board has been found and the author was allowed to personally examine and photograph it at the Illinois State Military Museum in his home town of Springfield, Illinois. The Lincoln Target Board allows us to see what sort of marksman our 16th president was but the bullet holes in the board raise some question as to just what version of the Spencer rifle President Lincoln fired on that historic and fateful day in August 1863. Part 1 of this presentation will first illustrate the various things that can be determined from bullet holes in wood e.g., approximate caliber, direction of fire, bullet composition and impact velocity. Part 2 will provide a brief history of the Spence rifles and carbines, the various types of ammunition for these firearms, multiple views of the Lincoln Target Board and what can be reasonably concluded from the dimensions of the bullet holes in this most famous of all targets.
ELEMENTAL VARIATION IN FLOAT GLASS
Abbegayle J. Dodds (Presenting author)(1); Edward M. "Chip" Pollock(1); Donald P. Land(2)
(1) Sacramento County District Attorney's Laboratory of Forensic Services; (2) UC Davis Dept of Chemistry & Grad Group in Forensic Science
Elemental analysis is a highly discriminating technique for the forensic analysis of glass samples. However, the significance of finding that two glass fragments are similar or dissimilar in elemental composition is difficult to assign since the potential for compositional variation has not been evaluated for common glass end-products. We investigated the natural variation in batches of float glass and automotive windshield float glass.
We used LA-ICP-MS to analyze manufacturer-quality control samples from two float glass furnaces in California. These quality control samples represented the glass produced by each manufacturer for one month in various years of production (1997, 2004 and 2005). From these analyses, we observed the potential for compositional variation between the left, center and right portions of the float glass ribbon. Additionally, one manufacturer exhibited variation in less than 24 hours of production. The other manufacturer did not exhibit such short-term variations; this float glass product was consistent in composition for a period of at least 72 hours. Both manufacturers' product exhibited variation over one months' time. The potential for short- and long-term variations in float glass production may result in sample heterogeneity or the ability to discriminate between samples manufactured in the same production lot.
To determine what effect the variation due to manufacture might have on a specific glass end product we collected and analyzed a total of 50 windshields by LA-ICP-MS. Compositional variation was examined at three levels: (1) withinpane variation, (2) between-pane variation, and (3) population variation. Ten windshields were used to determine withinpane variation and between-pane variation; all 50 windshields were used to evaluate compositional variation in a population of windshields. We found that windshields exhibit some heterogeneity that is not always statistically significant. Usually, these variations were within 10% of the mean value when elemental concentrations were greater than 1 μg g-1. Most of the windshields examined were composed of two significantly different panes of glass; however, certain manufacturers produced windshields using panes of glass produced from the same batch. The population variation in this group of 50 windshields was such that a preliminary grouping method resulted in twenty groups of indistinguishable panes of glass. Each group contained panes of glass produced in the same manufacturing lot; however, inner and outer panes of whole windshields were often distinguishable.
The results of this study show that the task of assigning significance to similar or dissimilar elemental profiles for questioned and reference glass fragments is not simple since elemental composition is not a unique characteristic and there is the potential of encountering heterogeneous float glass products in the forensic context.
PHOSPHINE GENERATION FROM CLANDESTINE METHAMPHETAMINE LABORATORY WASTE
Rochelle A Hranac, Forensic Science Graduate Student, University of California, Davis
The number of methamphetamine labs has increased over the last twenty years. With this increasing number, the knowledge of what chemicals that were used is a must. The most popular urban method of manufacturing methamphetamine is the red phosphorus/iodine method. This method is capable of producing very toxic gases such as hydrochloric acid gas, hydriodic gas, and phosphine gas. Current cleaning methods rely on the presence of methamphetamine in a lab cook area, where as the other materials, like the iodine or red phosphorus, needed to manufacture methamphetamine may still be present in the area. This small lab-scale study was designed to test amorphous red phosphorus for the creation of phosphine (PH3) gas. These results can inform officials what else can be present in a meth lab and perhaps alter the cleaning requirements for meth labs. The study subjects red phosphorus to four different relative humidity levels at four different temperatures and also to three metal oxides that the red phosphorus may come in contact with at a methamphetamine lab cook. These temperatures were 40, 30, 25, and 20°C with humidity levels from 20% to 80%. The three metal oxides were copper (I) oxide, iron (III) oxide, and aluminum oxide. After the uncontaminated red phosphorus was tested, waste red phosphorus was subjected to the resulting ideal conditions for phosphine to form. Due to some security concerns, the waste red phosphorus had no methamphetamine contamination. The red phosphorus was mixed with hydriodic acid and water, which is part of methamphetamine production. All that was missing was the ephedrine/pseudoephedrine from the mixture.
From preliminary results the 40°C 80% samples produced the most PH3 at twice the relative abundance of the 5% SF6 internal standard. The 20°C 20% samples gave the least amount of PH3 at one-third the relative abundance of the 5% SF6 internal standard. The higher and more humid samples were expected to produce the most phosphine, but this study will give numbers on how much phosphine can be produced. Unfortunately, the metals oxide samples did not give results as expected. Most samples did not give a detectable peak of phosphine.
NOW AND THEN - A BIOLOGIST'S PERSPECTIVE 40 YEARS ON
Dr Ann Priston, OBE, JP, Vice President, The Forensic Science Society, UK
Forty years ago guilty men walked free from justice because of lack of evidence. The last four decades have seen some of the most dramatic changes in the history of forensic examinations. Advances, not only in DNA but also in other branches of science, technology and policing have meant that many old cases can be revisited and offenders brought before the courts. The extreme sensitivity of DNA analysis by LCN has brought about dramatic changes in crime scene and laboratory practices and even criminal behaviour. Evidence presentation has changed along with court procedures which have reduced the time taken for cases to come to court. This paper takes a brief look at practices forty years ago and compares them with current methods, using cases examples as illustrations.
Brian Peterson, M.D.
Of the few truly controversial issues confronting modern forensic pathology, TASER-related deaths surely ranks near the top of the list. Somewhere in the intersection of drug use trends, restraint and control techniques, the aftermath of the Rodney King trials and the concept of "living better electrically" lurks the truth. But where? We will review drug effects, focusing on methamphetamine, cocaine and PCP. Following a detour through the world of excited delirium, we will focus on energy weapons and their effects, including the TASER. Finally, an approach will be suggested with respect to the analysis and disposition of in-custody, TASER-related deaths. Prepare to be shocked!
SERIAL SEXUAL ASSAULTING TWINS - WHICH ONE DID IT?
Shannon Cavness and Vince Deitchman, Oakland Police Department Crime Lab
This series of cases involves female victims and a pair of identical twins. Current methodologies of forensic DNA analyses do not allow us to distinguish identical twins. This particular series of cases highlights several things: common sense can answer many questions, DNA is not the answer for everything, fingerprints can differentiate identical twins and the marriage of forensic disciplines is very beneficial for the community.
In June of 2005, the Alameda County District Attorney's Office requested a sexual assault kit from 2004 be examined. The sperm fraction of the vaginal swab was entered into CODIS. This particular case had a known suspect from which a suspect sexual assault kit had been collected. The victim's DNA type was found on the swab of the suspect's penis and the suspect's DNA type was found on the victim's vaginal swab. This information was reported to the District Attorney's Office. Subsequently, we were informed that the suspect had a twin. Whether the twin was identical was unknown. Hmmm, I wonder which twin was responsible for this one.
In September of 2005 the 2004 case hit to an unsolved Oakland sexual assault case from 1995 in LDIS. The 1995 case was analyzed in 2001 using grant money from the OCJP Cold Hit Program. Unfortunately this assailant has a twin. It is unknown which of the twins was responsible for the 1995 sexual assault. In this series of cases there is no good twin/ bad twin dichotomy - just bad twins and neither of them was incarcerated at the time of the sexual assault. The assailant deposited a fingerprint on a Heineken beer bottle. Heineken beer bottles make great repositories for fingerprints. This fingerprint enabled us to place the responsible twin at the scene of the rape in 1995. Hmmm, I wonder which twin was responsible for this one.
Again grant money, this time from the NIJ, Backlog Reduction grant, enabled us to perform DNA typing on numerous sexual assault kits. The sperm fraction of the vaginal swab from a 2003 case was entered into CODIS. The profile hit to both the 2004 and 1995 cases in LDIS. Unfortunately this convicted offender had a twin (an identical twin). Sound familiar?
This paper will discuss the cases and how the laboratory aided in the identification of the perpetrator. Luckily we had good investigative work, strong witnesses, an intelligent jury and a hard-working district attorney team to convict the twin responsible. All of the answers will be divulged at the meeting...
WALK ON THE WILD SIDE: ANIMAL DNA ANALYSIS IN CRIMINAL INVESTIGATIONS
Elizabeth Wictum, Veterinary Genetics Forensic Unit, UC Davis School of Veterinary Medicine
The molecular analysis of human biological material has become widely accepted and a boon to forensic science. However, the use of animal DNA in crime scene investigations is largely underutilized. Once considered a curiosity, animal DNA evidence is receiving increased recognition and acceptance by law enforcement officers and the courts. There are an estimated 65 million pet dogs and 78 million pet cats in the United States. The close relationship between pets and their owners provides for abundant biological material and the potential for evidence transfer in the form of hair, saliva, urine, feces, and blood. Due to the grooming habits of cats and dogs, animal hairs can sometimes yield a DNA profile when human hairs would not. Animal DNA results have been used to link a perpetrator to a crime scene or victim in instances of homicide, burglary, arson, and sexual assault. In instances where the animal is the victim, we have used DNA to establish a pattern of abuse or to link a weapon to an individual animal. When the animal has been the aggressor, we have used DNA to illustrate the manner of the attack. Here we present an overview of cases where animal crime scene evidence was used to charge and prosecute those responsible.
FIELD REAGENTS FOR BLOOD ENHANCEMENT
Jason Kwast, Contra Costa County Office of the Sheriff Crime Lab
The field reagents used at our lab to enhance prints in blood will be discussed and compared. A few casework examples using leucocrystal violet, diaminobenzidine, and amido black will be shown. A limited number of common substances were tested using the reagents to assess specificity. The reagents' sensitivity with blood was also tested. The specificity and sensitivity results will be presented.
SHOOTING RECONSTRUCTION: THE VALUE OF EVIDENCE & ANALYSIS
Alexander Jason SCSA, CFPH, Independent Analyst
A double homicide occurred; the primary issue: was this a deliberate homicide or multiple acts of self-defense? The physical evidence, while substantial in quantity, was initially regarded to be of insignificant value in answering the key question.
This paper demonstrates the methodology involved in a multi-disciplinary approach to the reconstruction and analysis of a shooting incident in which bloodspatter, bullet impact damage, cartridge case locations, victim wound path evidence from the autopsy, and other elements are all integrated into an analysis which can be used to determine significant facts. These facts can then be utilized to determine what could and could not have occurred and specifically, which version - if any - of the incident is consistent with the physical evidence. Although a shooting incident reconstruction always includes the forensic crime laboratory analysis of the physical evidence, an effective reconstruction requires an understanding of the capabilities and dynamic characteristics of firearms, projectiles, ejected cartridge cases, gunshot residue and the dynamics involved in the production and projection of bloodspatter from gunshot wounds. A chemical test of physical evidence items provided confirmation of damage caused by bullets which contributed to the overall reconstruction and is an important tool in shooting reconstruction.
This case is an excellent example of how all these items can be integrated into an analysis and reconstruction. An ad- ditional important component in the overall reconstruction is the use of 3D computer animation modeling and the graphic enhancement of crime scene photographs. While both were used during the trial in the form of demonstrative exhibits, they were also used in the actual analysis and reconstruction. The detailed and scaled 3D computer model of the house in which the shootings occurred allowed the crime scene to be rotated and viewed at many perspectives which was very helpful in determining both possible bullet trajectories and the trajectories of ejected cartridge cases. This paper will discuss the crime, the methods of the analysis, and the reconstruction.
EVALUATION OF ZEOLITE AND CHITOSAN AS SUBSTRATES FOR COLLECTION AND STORAGE OF DNA
Steven B. Lee, Forensic Science Program, Justice Studies Department, San Jose State University
There have been two developments in the field of battlefield medicine, consisting of hemostatic agents made of unique materials. One of these is the QuikClot® hemostatic agent, made of zeolite, a silicate made from equal parts silicon tetroxide (SiO4) and aluminum tetroxide (AlO4). The other is the HemCon® hemostatic agent, made from chitosan, a starch found in the shells of shrimp. These bandages have already been deployed to armed forces and law enforcement agencies.
The mechanisms of hemostasis by the two agents differ, in that QuikClot® adsorbs the liquid from the blood, which is an exothermic reaction. The HemCon® agent uses the positive electrical charge of the chitosan molecules to attract the red blood cells to it, forming a clot in an extremely short time period, stopping profuse bleeding and allowing the body's natural healing processes to take hold.
This study has been initiated to determine the efficacy of recovery of DNA from blood bound in these two unique substrates. There are 4 areas of interest in this study:
- Recovery of "naked" DNA after introducing it to the substrates.
- Recovery of DNA from blood samples (whole blood) immediately following deposition onto the substrates.
- Recovery of DNA following storage of blood on the substrates at -30°C freezer for periods of 1 month to 1 year.
- Recovery of DNA following storage of blood on the substrates at room temperature for periods of 1 month to 1 year.
These last two areas of interest are to determine the efficacy of using such materials for storage of blood samples for DNA recovery that may be useful for DNA databases. It is felt the application of this study has potential for demonstrating a new method of recovering blood at crime scenes for later analysis which would reduce the possibility of exposure to blood borne pathogens by crime scene and law enforcement personnel. Additionally, there is the potential of using these agents as a means for obtaining DNA samples of suspects, who might use such products in an attempt to "self-treat" wounds received in violent encounters with law enforcement officers in order to avoid situations where the suspects put themselves at risk for detection and arrest, i.e., arriving at a hospital emergency room, seeking treatment for gunshot wounds. Furthermore, recovery of DNA from the used bandages may be useful for military investigations as both QC and HC have already been deployed to US armed forces.