110th SEMI-ANNUAL SEMINAR (Fall 2007)
CALIFORNIA ASSOCIATION OF CRIMINALISTS
October 15-19, 2007
ARE WE ANALYSTS OR INVESTIGATORS? - SHAKING UP THE SYSTEM
Peter D. Barnett and George Sensabaugh
This presentation is designed to challenge criminalists to think about the nature of their profession. Are criminalists evidence analysts or scientific investigators? Do criminalists respond to machines in their laboratories based on analysis requests from investigators and lawyers, or do they respond to incidents to determine if, and how, physical evidence can be used to understand what happened in that incident? What do we need to do in order to replace, or at least supplement, eyewitness testimony with a scientific investigation of the physical evidence? First, we must develop and appreciate the basic principles of criminalistics that describe how physical evidence is produced and why it is useful. Some basic principles have already been enumerated: Transfer (Locard), Individuality (Kirk), and Divisible Matter (Inman and Rudin). There may be more. Then criminalists must become proficient at developing and refining the operations that are used to give voice to the "mute" physical evidence. These "unit operations", as defined in the oft-repeated "definition" of criminalistics are recognition, preservation, identification, individualization, and reconstruction. Next, the results of the scientific investigation must be presented in a way that is scientifically rigorous, legally relevant, and understandable to the decision makers throughout the criminal justice process. Traditional scientific processes of peer review, hypothesis testing, and replication can satisfy this requirement. And finally, criminalists must convince the other players in, and observers of, the criminal justice process that this approach is valid and is of value in the investigation and adjudication of events that are the subject of legal inquiries. This may be the most difficult challenge in shaking up the system, but it is the essence of the responsibility of a professional. Transparency, comity, accessibility, and responsibility all can serve to enhance the acceptance of a process of scientific investigation as an integral part of the justice system.
BONES, BONES, BONES
Lorna Pierce, PhD, Santa Clara County Medical Examiner-Coroner
The role of the forensic anthropologist is to examine the skeletal material found in the county, and, if it is human, to provide a biological profile and taphonomic assessment in order to identify the individual. In California, Native American remains are frequently found and a different protocol is followed. Several cases that have come across my desk in the last twenty years will be discussed.
Katherine Borges, Society of Genetic Genealogy
A non-technical talk on Genetic genealogy in California.
SPERM COUNTING AND ITS USE IN EVALUATING POSTCOITAL INTERVAL
Edwin L. Jones, Jr., Ventura County Sheriff's Department Forensic Sciences Lab
In fertility studies, sperm counting was used to assess the sperm density of semen. The exposure to semen in the female reproductive tract was evaluated by counting sperm. In the Microscopy of Rape Evidence classroom, sperm counting was used as a quality assurance tool to test the students' ability to find and accurately identify sperm. Sperm counting was also used to evaluate the efficiency of various extraction techniques for sperm from different substrates. Counting sperm on a stained slide with no coverslip or mounting media consistently showed about 20% less sperm than counting the same sample with mounting media and coverslip. Counting sperm on the same slide with 400 and 600 times magnification showed consistently more sperm at 600X. Sperm counting was found to be of assistance in evaluating the postcoital interval (PCI) also known as time since intercourse (TSI) of samples from rape-murder cases. The techniques of sperm counting will be presented so that you can use the data with the published literature in the area of PCI. The extensive literature in the field of PCI will be discussed in relation to the types of sampling methods (swabs, smears on microscope slides and vaginal washings). One paper from this literature stands out as being useful for assessing PCI because the female volunteers were active after sex and it used 12 or more sperm to define the "4+" rating of sperm (1). The author will present a method for obtaining better data from the samples normally encountered in sexual assault investigations. This method involves counting the number of sperm and the number of nucleated squamous epithelial cells in each field of view.
1. Garlo AM. Phoshoglucomutase and esterase D activity in post-coital vaginal swabs. J Forensic Sci Soc 25:301-11.
MICROBIAL COMMUNITY DNA PROFILING: SAMPLE SIMILARITY AND GEOGRAPHIC PROXIMITY IN A LARGE DATABASE
George Sensabaugh, School of Public Health, University of California, Berkeley; Gabriel Llinas, Forensic Science Program, University of California, Davis
The forensic utility of microbial community DNA profiling as a tool for the analysis of soil evidence depends on its capacity to correctly link soil samples that may have originated from a common source and its capacity to differentiate samples that originate from unrelated sites. We have investigated the relationship of profile similarity to geographical proximity in a database of 1348 community DNA profiles of ascomycete fungi derived from samples collected according to a spatially structured sampling grid at 24 distinct sites from an arid region of New South Wales, Australia [Green, et al., Nature 432: 747, 2004]. Distances between samples ranged from 1 m to over 100 km. Profiles were compared using three statistical approaches: (a) pairwise sample similarity measures using the Sorensen and Morisita-Horn indices, (b) hierarchical cluster analysis using Pearson correlation statistics, and (c) principal components analysis.
We have found that none of the statistical approaches reliably differentiated geographically proximal (1 m sq. plots) from geographically unrelated sites (d > 250 m). Samples from unrelated sites were found to have highly similar profiles, indicating a substantial risk of false positive source attribution. Conversely, some samples from geographically proximal sites had quite dissimilar profiles, indicating that profile dissimilarity was not a reliable indicator of source exclusion.
These findings indicate that more foundational research is needed before microbial community DNA profiling is embraced or rejected as a tool for forensic soil analysis. Several directions for future research are suggested. First, the sample profiles characterized here were "species poor" with relatively few OTUs per profile. Species richness may need to exceed some minimum threshold to achieve forensically reliable profiles.
Second, it is possible that the ascomycete fungi were a poor species group on which to base geographic similarity comparisons. Differences in sample discrimination potential for different microbial species groups deserve investigation.
Third, the lack of consistency between the results provided by the different statistical approaches, though likely a consequence of the limited species diversity in the profiles, calls into question the choice among different methods of statistical analysis to be used for profile comparisons.
We thank the CAC and the A. Reed and Virginia McLaughlin Endowment for providing funds to support this pilot project.
AN UNUSUAL PROJECTILE: SHEAR GENIUS OR SHEAR STUPIDITY?
Gregory Laskowski, Kern County District Attorney's Office
In April of 2007 a gentleman was mowing his front lawn in the town of McFarland, when a car drove up and two shots were believed to have been from the vehicle. The victim sustained a penetrating wound to his chest, and was transported to a nearby hospital. While at the hospital emergency room, an unusual object was removed from the chest wound. At the scene of the shooting strange debris littered the front yard of the victim's residence. Two apparent bullet holes were observed to house, one into the stucco facing of the garage, and the other perforating the window of garage door This second shot then traversed the garage, perforated an interior wall, struck a ceiling lamp, rebounded off a cabinet door resulting in a bullet coming to rest in the washing machine. This paper will describe the attempt to identify the projectile that struck the victim, who by-the-way survived his wound, the identification of the weapon that fired the bullet, and the suspicious debris littering the front lawn. A video re-enactment of the reconstructed device will accompany this presentation.
PHYSICAL MATCHING AS A DUTY OF A FIREARMS AND TOOLMARK EXAMINER
Jaco Swanepoel, Forensic Analytical
Edmond Locard's Exchange Principal is one of the cornerstones of forensic investigations and states that when two objects come in contact with each other they exchange trace materials, markings and possibly other significant evidence. Two objects or surfaces that have been in contact with each other for any period of time should (under most circumstances) leave their respective markings or traces upon one another. Through careful examination and comparison such markings and traces can be detected possibly leading to the conclusion that the two objects or surfaces were in fact joined or in contact with each other. This case examination profiles a rare and unique dual-impression and examiners are looking at markings that were cross transferred from one surface to another. It is also important to examine the transferred markings in relation to their size, shape, position and orientation, as well as their individual significance. The markings are found on the bottom of a hydraulic pump and on the base plate that connects the hydraulic pump to the Grader it was stolen from. The Detective Service wanted the South African Police Services Forensic Science Laboratory to determine if the base plate and the hydraulic pump were connected to each other at one point or another.
DNA IN WILDLIFE FORENSIC SCIENCE IN CALIFORNIA: A STATUS REPORT
Jeff A Rodzen, James D. Banks, Erin P. Meredith, California Dept of Fish and Game, Wildlife Forensics Lab
The Wildlife Forensics Laboratory has assisted in species identification and processing of evidentiary samples from a large number of wildlife species in California. The use of STRs is playing a very important role in wildlife forensic science. Unlike human criminalistics, the WFL analyzes many different species, each of which must have its own unique and species-specific set of STRs and corresponding database of multilocus profiles. We provide an overview of our research to date on population and forensic genetics of deer, elk, and mountain lions and overcoming a Kelly-Frye challenge. New research projects will also be reviewed and include the development of STRs for bear, red and black abalone, and the polyploid white sturgeon.
THE SAN DIEGO DNA PROJECT
Judge George "Woody" Clark
The San Diego County District Attorney's Office "DNA Project" was begun in June 2000 to proactively examine the cases of defendants who were prosecuted by the San Diego District Attorney's Office in 1992 or earlier. 1992 was selected based on the fact DNA testing was commonly available and routinely applied in criminal cases in San Diego after that time. The review focused on whether, in each case, biological evidence still existed, whether the defendant consistently maintained his or her innocence based upon mistaken or wrongful identification, and whether current DNA technology could provide exonerating evidence. The project included review of more than 600 cases. The program received national attention for its innovation, was recognized by Time Magazine, and honored by the Harvard University John F. Kennedy School of Government. This presentation will review the procedures employed in the project, describe its implementation, and detail the results of the process.
OPPORTUNITIES AND LIMITATIONS OF FORENSIC ENTOMOLOGY
Robert B. Kimsey, Ph.D.
Entomology suffers much from the portrayal of forensic entomologists and the work they do in the public media, particularly in Television programs like CSI. Although the other forensic sciences suffer in much the same way, the difficulties caused entomology couple with the relative newness of this rapidly developing science to redouble misconceptions of what this field has to offer. Herein (1) I review technical stumbling blocks in forensic entomology and (2) the inherent limitations of the field, then describe the (3) major research efforts forensic entomologists currently struggle with, and (4) describe the progress and future of this potentially lucrative field. Although the "going will be rough" I argue that forensic entomology has a very bright future.
EVALUATION OF ZEOLITE AND DNA-SAMPLEMATRIX(R) AND FOR COLLECTION AND STORAGE OF DNA
Brie Silva, Kimberly Clabaugh, Kingsley Odigie and Steven B. Lee: Forensic Science, Justice Studies Department, San Jose State University
Collection and storage of DNA samples is of paramount importance in forensic DNA, epidemiological, clinical and virtually any molecular genetic laboratory. In forensic laboratories there is always the possibility that cases may be reopened and any stored biological evidence or extracted DNA sample may need to be re-tested. This is especially important when the amount of sample is limited. Proper storage of samples containing small amounts of DNA is important for maintaining sample integrity over time.
The objectives of this paper are: 1) To determine the efficacy of recovery of DNA from whole blood bound in the Zeolite in QuikClot® following storage at room temperature and -20°C freezer for periods of 1 week to 4 years and; 2) To evaluate a new substance, DNA-SampleMatrix® for long-term storage of DNA samples at room temperature and -20°C freezer over 6 months.
QuikClot® is a hemostatic agent, made of zeolite, a silicate made from equal parts silicon tetroxide (SiO4) and aluminum tetroxide (AlO4). Zeolite in the QuikClot® absorbs liquid in the blood, resulting in hemostasis and is therefore used in bandages to rapidly stop bleeding. 25ul aliquots of Bovine blood were placed on replicates of QC and then stored at room temperature or -20°C. 3 replicate samples from each temperature were extracted periodically over 1 year. Samples have been prepared to continue time points out to 4 years. Quantification was performed using standard agarose gel electrophoresis. Results on samples stored up to 3 months were stable at room temperature however DNA recovered from QC saturated with Bovine blood after 13 months of storage at room temperature yielded low amounts of degraded DNA. Results from replicates of 25ul blood aliquots out to 1 year will also be presented.
Biomatrica, Inc. has developed a technology that allows for the stable, dry storage of biological materials at ambient temperatures. The quality and quantity of control DNA (K562) recovered from room temperature and -20°C dry storage in DNA-SampleMatrix® versus standard microfuge tubes at various time intervals is being assessed. Preliminary results indicate that the integrity is maintained in DNA-SampleMatrix® over 3 months versus those stored in standard microfuge tubes. Samples stored in DNA-SampleMatrix® were amplified using Profiler Plus. No detectable inhibition to PCR amplification was observed. Results from replicates out to 6 months as well as results from degraded DNA samples will also be presented.
THE ZODIAC KILLER
Mike Taylor, Reporter, San Francisco Chronicle
In the 33 years since the killings, the San Francisco Police Department has amassed enough evidence and leads to fill an entire filing cabinet. Today, fewer than half of the envelopes sent by the killer remain, the rest having disappeared during three decades of handling by hundreds of local, state and federal investigators. The department's DNA testing unit is testing the envelopes using a DNA technique known as polymerase chain reaction, or PCR, which can develop a genetic profile from as few as 50 human cells. A genetic profile would allow investigators to search for a match among the hundreds of thousands of genetic profiles of known criminals in national databases - as well as among the possible suspects listed in the department's Zodiac files. The lab has found a partial DNA "fingerprint" on one of the envelopes, but not enough for definitive matching. However, a Primetime investigation prompted the discovery of three envelopes that offer new hope. The envelopes were thought to have been lost, but an anonymous Primetime source - a long-retired investigator - found them, in mint condition, during a search of his personal files and turned them over to the San Francisco police. "The potential is exciting," said Dr. Cydne Holt, supervisor of the San Francisco Police Department's DNA lab. "If there are cells on those envelopes, we will get the DNA from them and get an answer. ... The prospect of being able to contribute to the story is exciting."
NO BODY INVESTIGATION AND HOMICIDE PROSECUTION: THE CHRISTIE WILSON CASE
Garen Horst, DDA, Placer County District Attorney's Office
The successful investigation and prosecution of a murder case where no body was recovered is presented. Actual exhibits from the jury trial will be shown, along with a narrative of the forensic evidence collection, processing and interpretation that proved so useful in this case.
THE RECOVERY, CHARACTERIZATION AND ASSESSMENT OF CONTACT DNA COLLECTED FROM FIREARMS USING A QPCR TRIPLEX METHOD AND STR ANALYSIS
Pamela Hofsass, UC Davis Forensic Science Master's Program
Contact DNA describes a transfer of cellular material onto the surface of any item handled by a person. The objective of this study is to determine how much DNA can be expected to be found on trigger, slide and grip swabs taken from firearms under ideal conditions using standard casework methodology. Additionally, does the DNA profile detected reflect the profile of the last person who handled this firearm?
Forty-four recruits from the SFPD Police Academy provided their handled firearms for sampling after a required shoot at the Police Range. These firearms (all model P226 SigSauer 40 cal handguns) were immediately sampled after the last round of fire using sterile cotton-tipped swabs. Two sets of samples were collected; Set 1 from 22 recruits provided grips and trigger areas samples. Set 2 from 22 recruits provided grips, trigger and slide area samples. All samples were extracted using a standard organic phenol extraction method at the DOJ Jan Bashinski DNA Lab in Pt Richmond, CA. All extracts were analyzed using a DOJ-based RT qPCR Triplex method followed by Profiler Plus AmpFlSTR™ amplification and typing system. DNA was successfully recovered from all three areas targeted for sampling; grips, trigger and slide. Genetic analysis data was described in qualitative terms of profile recovered (e.g. - Full, Major/Minor, Mixture, Partial and No Profile). Data will be presented in terms of correlation between sampling sites, qPCR results versus ng DNA recovered as well as Profile obtained versus qPCR THO1/CSF Ratio. In addition, collection techniques and suggestions for potential future studies will be discussed.
HURRICANE KATRINA FORENSIC DNA CO-OP
Amanda Sozer, Ph.D.
The presentation will provide the audience information on the Hurricane Katrina mass fatality DNA identifications and the forensic cooperative that was deployed. Recommendations for implementing a large-scale DNA identification project in response to future mass fatalities will also be presented. In August 2005, Hurricane Katrina devastated an area of the Unites States equaling the size of Great Britain. Over 1300 individuals lost their lives, many as a result of the flooding which occurred when the New Orleans' levies broke. The victims were identified by forensic methods. DNA played a major role in the identification of victims and was used exclusively in many cases where fingerprints and dental records were unavailable.
The DNA identification effort was challenging because many of Katrina's missing victims lost their identifying personal reference items in the disaster. Personal reference items such as toothbrushes, clothing, and hairbrushes which could contain the victim's DNA were destroyed by the flooding. In addition, biological family members whose DNA could be used to make kinship identifications were evacuated to locations throughout the country and relocated multiple times following the storm. Locating and contacting family members was difficult and made the collection of the family reference samples difficult. Inconsistencies between reported and actual genetic relationships added to the complexity of the project. Genetic pedigrees were constructed for each reported missing and complex kinship analysis was performed to identify the victims in the majority of cases. Forensic DNA Analysts from Crime Laboratories across the United States participated in a Forensic DNA Co-Op to assist in the DNA identification effort. In addition, Genetic Counselors from 80 institutions volunteered to work with the families. By using lessons learned from previous mass fatality DNA responses, once funding was obtained, DNA identifications were made accurately and rapidly.
It is important to incorporate the lessons learned from the Hurricane Katrina DNA identification effort into future mass fatality response plans. Recommendations will be made for a possible future forensic cooperative.
FORENSIC ODONTOLOGY (DENTISTRY)
James D. Wood, D.D.S., Cloverdale, CA
Forensic Odontology can be a valuable tool for the Criminalist. Forensic Dentistry has been used for human identification for many years and is well accepted for accuracy, time, and cost to law enforcement agencies. In addition, forensic odontology can be used for the analysis of bitemarks - human and animal. This presentation will provide an overview of current forensic dental techniques and their application.