112th SEMI-ANNUAL SEMINAR (Fall 2008)
CALIFORNIA ASSOCIATION OF CRIMINALISTS
October 20-28, 2008
MICRO-MARKED FIRING PINS: CHARACTER DURABILITY AND MICRO MARK LEGIBILITY
Frederic Tulleners*, MA and David Howitt, PhD, UC Davis Forensic Science Graduate Program; Michael Beddow, MS, Phoenix Police Department
The laser machining of microscopic encoding structures on specific firearm components has been proposed to assist in the identification of expended ammunition components found at crime scenes. This study involved the testing of firing pins by placing up to 8 alpha numeric digits on a firing pin with a diameter of 0.075". These micro-marked firing pins contained three different forms of encoding: alphanumeric, gear and radial bar codes. The durability of these micro characters and legibility of their impressions were observed by the testing of eleven semi-automatic pistols, two semi-automatic rifles and a pump action shotgun with different ammunition.
The firing pins were evaluated before and after using the scanning electron microscope to document subsequent areas of firing pin encoding degradation. The micro serial impressed on the fired cartridge case primer was evaluated using a stereo microscope equipped with Schott ring light and a polarizer/analyzer. The legibility of the impressions produced by these micro-marked firing pins varied between firearms. Transfer rates were observed from zero to 100% for all encoding formats. Three major factors affected the legibility of the impressed characters for each of the firearms tested: ammunition brand, firing pin drag, and multiple strikes of the firing pin within the same impression.
ELIMINATING SUBJECTIVITY IN THE EVALUATION OF IMPRESSION EVIDENCE
David Howitt, PhD, UC Davis, Forensic Science Graduate Program
With the advent of the Daubert decision and the precise statistical justification associated with DNA analysis there has been more and more criticism of forensic examiners and the subjectivity of their evidence. The requirement that examiners provide an assessment of the likelihood that the evidence they present could have come about by pure chance is long overdue. In the analysis of tool marks some forensic examiners have already adopted a simple methodology, consecutive line matching, that in combination with compiled databases is highly unlikely to have been coincidental. This paper outlines the general principles that determine the significance of a particular correspondence of impression evidence, what is known about these comparisons and the way in which the calculation of the corresponding probability, that it could have occurred by pure chance, can be done.
DISPERSIVE AND FT-RAMAN ANALYSIS OF FORENSIC SAMPLES
Jesse Gallop, Sr. Sales Engineer, Thermo Fisher Scientific
The use of both macro and micro infrared spectroscopy is well-established in the crime lab. In a macro mode, it is used primarily for drug analysis while the micro mode is used for trace evidence. Recently, there has been a growing interest in using Raman spectroscopy as a compliment to infrared spectroscopy. Raman spectroscopy offers several advantages over infrared spectroscopy.
Raman analysis can be performed on solids and liquids (including water), in both macro and micro modes. In the macro mode, unknown liquid and solid samples can be analyzed through glass vials or plastic bags. In the micro mode, samples that are in the 1 to 2 micron range can be analyzed. This is ten times better spatial resolution than infrared spectroscopy. This allows the examination of individual drugs and crystals. It also allows the probing of individual paint layers "in situ" with little or no sample preparation. The utility of Raman spectroscopy for drug analysis, fiber identification, paint analysis, and explosives will be discussed. A comparison of the FT and dispersive Raman techniques will also be discussed.
ISOMER DETERMINATION OF CATHINE IN KHAT
Rochelle Hranac, Arizona Department of Public Safety; Lon Anderson, Drug Enforcement Administration, Southwest Laboratory
Catha edulis (Khat) is an evergreen shrub native to the Horn of Africa. The leaves are chewed to obtain a "high" from the stimulant-type compounds found in the leaves. These compounds include cathinone and cathine, both listed as Scheduled Controlled Substances by the US federal government. Five extraction methods were performed on dried Khat leaves to successfully remove and identify cathinone and cathine. These methods were Methanol, two Basic Extracts, Dry Basic Extract, and Acid-Base Extract. Gas chromatography with flame-ionization and mass spectrometer detectors were used for analysis. Cathine, (+)-norpseudoephedrine, must be individualized from (-)-norpseudoephedrine and (+)- , (-)-norephedrine. A GC/FID with a chiral column was used for the identification of cathine. Each extract had positive and negative aspects, but the Acid-Base Extract had the best concentration with clear chromatography. These attributes made it most suitable for analysis with the chiral GC/FID.
A TECHNIQUE FOR IMPROVED LOW-LIGHT BLOODSTAIN PATTERN PHOTOGRAPHS
Phillip Hess, Sacramento County District Atty's Laboratory of Forensic Services
This presentation is a review of photographic techniques employed during the documentation of a 2007 homicide case which took place inside of the Folsom Prison. The suspect and victim were housed together in a jail cell in the maximum security area of the prison. This presentation focuses on the bloodstain evidence which required specific photographic techniques and the use of Blue Star Forensic (a luminol based product). A brief explanation of the photographic set up and the final product created using Photoshop CS3 will demonstrate some useful techniques. This method can be employed to create improved final images of extremely low light situations commonly encountered with the chemical enhancement of "hidden" bloodstain patterns.
A QUALITATIVE CHARACTERIZATION OF LEAD-FREE 9MM AMMUNITION AND ITS SIGNIFICANCE ON THE HANDS OF A SHOOTER
Angela Hansen, UC Davis, Forensic Science Graduate Program; Faye Springer (contact), Sacramento County District Atty's Laboratory of Forensic Services
Historically, gunshot reside has been characterized by the presence of lead (Pb), barium (Ba), and antimony (Sb). However, with an increase in environmental awareness about lead contamination in nature and at firing ranges, the need for lead-free ammunition is becoming more prevalent. Sixteen different types of 9mm ammunition advertised as lead-free ammunition from fourteen manufactures (CCI Blazer Clean Fire ™, Sinterfire Lead-Free Ammunition ™, Winchester Super-X ™ (Super Unleaded(1)), Winchester Winclean ™, Winchester Superclean NT ™, Ruag Action 1 [+P] ™, DFA ™, Zero ™, Remington UMC ™, Remington Disintegrater ™, Speer Lawman Cleanfire ™, Simunition CQT™, Extreme Shock ™, Federal Ballisticlean ™, M&D ™, Precision FireFrangible™, PMC Green (TM)) were individually test fired and gunshot residue samples were collected from the shooters hand. Each brand of ammunitions was disassembled into the gunpowder, bullet, anvil (where applicable), primer cup and cartridge case. The primer cup was placed in a clean device and detonated directly onto a collection stub.
Additionally, samples were collected from the hands of employees of various occupations, in addition to direct sampling of different materials within that environment. All samples were then analyzed semi-qualitatively using a LEO Scanning Electron Microscope (SEM) with an INCA X-sight Energy Dispersive X-Ray Detector (EDS) and their elemental compositions were determined. The elemental compositions of the particles from these environmental and occupational samples were than compared to elemental composition of the different brands of ammunition.
(1) Winchester Super-X ™ has also been referred to as Super Unleaded, however, this ammunition has been discontinued.
FORENSIC DEVELOPMENT OF LA-ICP-MS: ELEMENTAL PROFILING OF SODA-LIME CONTAINER GLASS
Karen Harrington, Sacramento County District Atty's Laboratory of Forensic Services
Elemental analysis is a method of adding discrimination to glass evidence analyses. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) makes use of a high power laser to create an aerosol of fine glass particles by irradiating the surface of a glass fragment which can then be analyzed using ICP-MS. The natural elemental variation of soda-lime container glass has continued to present difficulties in establishing the extent of discrimination possible between bottles manufactured from the same plant. The purpose of this project is to provide an evaluation of the degree of evidentiary value which may be attributed to indistinguishable soda-lime bottle samples. Ultimately, this project will aim to establish a set of match criteria that remains strict enough to minimize false positives but allows for enough variability to reduce false negatives (in essence, to treat a bottle as a uniform unit). Results indicate that within-bottle elemental variation requires the use of at least +/- 2 standard deviation range-overlap match criteria to allow for the treatment of bottles as a whole unit. Additionally, profiles of bottles originating from the same furnace within a day are likely not distinguishable. Profiles of bottles originating from the same furnace were consistently distinguishable outside of a 2 week production run. Profiles of different colored samples originating form different furnaces were found to be distinguishable. This demonstrates that LA-ICP-MS can reasonably be applied to soda-lime container glass evidence for assisting in distinguishing between samples when these time variable constraints are considered.
SEARCH, THE NATIONAL CONSORTIUM FOR JUSTICE INFORMATION AND STATISTICS
Rich Harris, Director, High Tech Crime Training Services, SEARCH
Mr. Harris will present an overview of SEARCH, the National Consortium for Justice Information and Statistics, including the history of the not-for-profit organization and a description of the services SEARCH provides to the criminal justice community. Mr. Harris will focus most of the presentation on the High-Tech crime Training Services that are available through SEARCH and will present an overview regarding the current state of cellular telephone investigations as well as current trends in other wireless technologies.
VALIDATION OF ABI AMPFlSTR® MINIFILER™ KIT
Wanda Kuperus*, Ph. D, Cassie Johnson, M.S., Orchid Cellmark
Most forensic laboratories are accustomed to using at least some of the commercially available STR kits such as ABI's ProfilerPlus ®, COfiler ®, Identifiler ®, as well as Promega's PowerPlex16 ® in the genotyping of DNA samples for human identification. These are the STR kits of choice for most DNA samples and have proven to be reliable products. However, the ability of these same laboratories to process the most challenging samples may benefit from the implementation of an amplification method that offers the ability to genotype shorter STR fragments, is more resistant to PCR inhibition, and also requires less DNA to produce results. Thus, the ABI AmpFlSTR® MiniFiler™ Kit has been optimized for typing degraded DNA and samples containing PCR inhibitors. To comply with Orchid Cellmark's Quality Program and to ascertain whether the MiniFiler system is an appropriate technology to introduce into the laboratory's forensic operations, a thorough internal validation study was conducted. This study include: (1) sensitivity, (2) reproducibility and precision, (3) mixture analysis, (4) inhibition, (5) degradation, (6) known and non-probative samples and (7) stutter analysis. Some of the results of this validation, as well as the results of OC's application of this forensic typing system into actual casework samples will be presented.
VALIDATION OF THE APPLIED BIOSYSTEMS' AMPFlSTR® MINIFILER™ PCR AMPLIFICATION KIT
Joy Viray, Sacramento County District Atty's Laboratory of Forensic Services
The Applied Biosystems' AmpFlSTR® MiniFiler™ PCR amplification kit was validated for forensic casework use in the Biology Unit of the Sacramento County District Attorney's Laboratory of Forensic Services. A brief summary of validation results will be presented. In addition, an inhibition study was performed to compare the performance of both Identifiler™ and Minifiler™ on biological fluids applied to mock casework substrates. Contact DNA experiment results highlighted: 1) the exceptional sensitivity of the Minifiler™ kit, 2) the success of extracting contact DNA samples using an automated robotic platform with a modified protocol, and 3) high-contact laboratory surfaces as potential sources of cellular material that could be transferred and detected.
NOMENCLATURE DEVELOPMENT FOR CANINE STR PANEL
Bradley Tom, et. al., UC Davis, Forensic Science Graduate Program
The American Pet Products Manufacturers Association 2007-2008 National Pet Owners survey found that 39% of U.S. households have at least one dog. With dogs being in such close contact with humans, information from the canine evidence is potentially crucial to crime scene investigation. When evidence from a dog is available, a method for match comparison and probability estimates would be advantageous to investigators. In conjunction with my PI's project, which aims to develop a standardized and validated canine STR panel for forensic use, my project was to develop an allelic nomenclature system for that panel.
The use of a panel of standardized loci in all investigations would make it easier for interlaboratory comparison of information. The allelic nomenclature that I propose will provide a more accurate picture of STR allele distribution pattern and frequencies among the various U.S. canine subpopulations. This information is absolutely relevant for the accuracy and precision of canine forensic genetic testing in the U.S.
FACILITATING COMMUNICATION AND COLLABORATION BETWEEN THE FORENSIC SCIENCE COMMUNITY AND THE INNOCENCE MOVEMENT
Keith Inman, Forensic Analytical, Cal State East Bay
Panel: Norah Rudin (private consultant), Linda Starr (NCIP), Gabriel Oberfield (TIP), forensic community representative (TBA)
In speaking with our colleagues in the forensic community and our associates in the innocence movement, it has become clear to us that strong feelings exist amongst and betwixt both groups. We also began to understand that false assumptions, miscommunications, and misunderstandings were contributing to a growing tension. We addressed some of the issues in our editorial, "Who speaks for Forensic Science", published in the recent CACNews, 4th quarter, 2008 (www.cacnews.org/news/4thq08.pdf).
This workshop will bring together the two communities in a forum intended to foster open communication and discussion. Representatives of both the Northern California Innocence Project (NCIP) and The Innocence Project (TIP) will be present to discuss both the specific workflow of an innocence case and public policy goals of the innocence movement. It is our hope and intent that this workshop will facilitate the continued collaboration of forensic science and the innocence movement.
PEOPLE VS. PHILLIP THOMPSON
Trish Kelliher, El Dorado County District Attorney's Office
On June 19, 1971, victim Elizabeth Cloer's body, naked except for her bra, was found in El Dorado County. She had been shot and her face was crushed beyond recognition. Her panties were found several yards from her body. Elizabeth was last seen leaving her Sacramento apartment with a man she had met earlier in the evening at a gas station.
All leads in the case were exhausted and the case lay dormant until 2002, when the evidence was re-examined as part of the Department of Justice Cold Hit Program. Criminalist Angelynn Moore examined the victim's panties and was able to extract DNA from sperm found in the panties. A profile was obtained and uploaded into CODIS. The profile matched that of prison inmate, Phillip Arthur Thompson, who was serving a life sentence for kidnap and robbery. Criminalist Moore was able to link the panties to the victim when she found that the DNA profile from the blood on the victim's bra matched the female profile found in the panties. Alleles foreign to both Thompson and the victim were found on the waistband of the panties. However, it was shown that in 1971, evidence was frequently handled without gloves by investigators and criminalists.
At trial, in an obvious attempt to explain the DNA findings, Thompson testified that he had at some point had sex with the victim, however, did not murder her. Thompson was convicted of first degree murder and sentenced to 7 years to life, which was the sentence for the crime in 1971.
SUMMER OF TERROR
Faye Springer, Sacramento County District Atty's Laboratory of Forensic Services
In the summer of 1999, three Synagogues in the city of Sacramento were burned by arsonists in a period of a few hours. In the following month, a gay couple was murdered while asleep in their home in the Redding area of California. This incident was followed by the burning of an office building in Sacramento that housed an abortion clinic. A task force of federal and local law enforcement agencies was formed to investigate these crimes. Eventually, physical evidence linked two brothers from the Redding area to these crimes. The brothers harbored fanatical religious convictions that were anti-Semitic and anti-homosexual. This paper will discuss the trace evidence that linked the Sacramento crimes to these brothers.
RECOVERY OF DNA AND FINGERPRINTS FROM TOUCHED DOCUMENTS
Jonathan Sewell, et. al., King's College London and London Metropolitan Police
This study investigated the various factors affecting DNA profiling from DNA recovered from fingerprints deposited on paper before and after fingerprint enhancement treatments. The DNeasy1 plant mini kit (QIAGEN1) was found to improve DNA recovery from paper by over 150% compared with the QIAamp1 mini-kit. A significant decrease in the amount of DNA recovered was observed following treatment with DFO and/or ninhydrin. This decrease in yield did not have a comparably significant effect on the quality of the SGM Plus™ profiles. Furthermore, this study found that whilst certain paper types, such as newspaper, magazine and filter paper allowed for the good recovery of DNA, common office paper and white card strongly interfered with the recovery of DNA resulting in poor quality profiles.
A STUDY OF UNUSUAL QUADRUPLEX QPCR DATA
Kyle Duke, UC Davis, Forensic Science Graduate Program
The Method Development Group at the CA DOJ Jan Bashinski DNA lab has recently implemented a quadruplex real-time PCR assay that can be used to estimate the quantity of DNA in an unknown sample as well as detect the presence of inhibitory substances and/or degraded DNA. This assay improves upon a previous design by adding a Y-chromosome amplification target to quantify male specific DNA in addition to the autosomal targets used in previous assays developed by the laboratory. Population studies using the new quadruplex identified three male samples that displayed abnormally low Y-chromosome signals. The objective of my thesis project was to study these samples in an effort to determine possible sources of the low male-specific signal. A variety of hypotheses explaining the phenomenon were explored using sequencing technology and STR typing with ABI's Identifiler and Yfiler kits, as well as a battery of quantification systems with divergent methods of DNA detection. None of the competing hypotheses satisfactorily accounted for the low Y quantifications. Double-strand breaks within the Y chromosome qPCR target remain as a possible source of the effect, but not one that could be explored in these series of experiments due to limited sample amounts.
GENERATING FORENSIC DNA PROFILES FROM "CONTACT DNA" ON CARTRIDGE CASINGS AND GUN GRIPS
Lisa Branch, California State University Sacramento
In the United States, ten thousand homicides occur each year involving the use of guns, making gunshot wounds the leading cause of death by homicide. Despite the best efforts of law enforcement agencies and prosecutors, more than thirty five percent of homicides are never solved. Thus, there is a great deal of interest in developing new methods to analyze evidence from crime scenes in which firearms are used. In this study, 600 cartridge casings and 90 gun grips were examined to determine if it was possible to obtain DNA profiles from contact DNA. DNA extraction was performed using the BioRobot EZ1, and the samples were amplified first with AmpFlSTR® Minifiler™ then quantitated using Quantifiler™ to determine if amplification with AmpFlSTR® Identifiler could be done. Only 7.6% of unfired cartridge casings contained significant DNA to generate a partial or full profile using Minifiler, and only 0.76% of fired cartridge casings contained significant DNA to generate profiles. While 55% of gun grips contained either a partial or full DNA profile. It was shown that even though it is possible to obtain a DNA profile from unfired cartridge casings using both Minifiler and Identifiler, it is very unlikely that a DNA profile will be obtained from cartridge casings collected at crime scenes.
SODIUM HYDROXIDE EXTRACTION OF DNA FROM BUCCAL AND BLOODSTAIN SAMPLES
Christopher Tanforan*, Yeung Kung, California Department of Justice, Jan Bashinski DNA Laboratory
The Jan Bashinski DNA Laboratory Data Bank processes samples from convicted offenders and qualified arrestees. The samples are extracted, amplified, analyzed, and genotyped. The genetic profiles of the samples are then entered into a searchable database.
The Data Bank is a high-throughput laboratory environment which requires the capability of processing upwards of thirty thousand samples a month. The sodium hydroxide extraction was developed and implemented in order to meet this need.
The sodium hydroxide extraction method provides a fast, efficient method for extracting DNA from buccal and bloodstain samples. The advantages of the sodium hydroxide extraction compared to a commercial extraction kit are discussed, as are some of the limitations of the sodium hydroxide extraction method.
RETENTION OF GUNSHOT RESIDUE ON FABRICS
Samantha Frost, UC Davis, Forensic Science Graduate Program; Faye Springer, (contact) Sacramento County District Attorney's Laboratory of Forensic Services
The aim of this study is to determine how quickly gunshot residue (GSR) disappears from a subject's clothing during common, low intensity activities such as driving, walking and sitting, and high intensity activities, such as dancing and running. In this study, I placed 200 μl of ethyl alcohol containing approximately 200 GSR particles, 1-10 μm in size, on 100% cotton fabrics, 100% polyester fabrics, and 50-50 cotton polyester blend fabrics. Subjects wore these fabrics for time intervals from 30 minutes to 4 hours. Then, gunshot residue samples were collected from the fabric using carbon adhesive on aluminum stubs. I also washed each type of fabric after depositing gunshot residue particles on the clothing and collected samples for analysis after the fabric was washed and laid out to dry. The analysis of gunshot residue particles was done using the scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS). The result of this study will be presented.
OFFICER INVOLVED SHOOTINGS AND SUICIDE BY COP PHENOMENON
Kenton S. Wong, Forensic Analytical Sciences, Inc.
The presentation will examine a case involving an officer involved shooting that had an apparent suicide by cop aspect to the case. The case presentation will highlight the forensic crime scene reconstruction of the case and alert meeting attendees to the potential motive of suicide by cop phenomenon occurring in all officer involved shootings.
FIREARM AND TOOLMARK IDENTIFICATION - MEETING THE DAUBERT RELIABILITY CHALLENGE; CAC NORTHERN CALIFORNIA FIREARMS STUDY GROUP CMS SURVEY; HOW USING CONSECUTIVE MATCHING STRIAE (CMS) HELPS MEET THE MAIN DAUBERT REQUIREMENT
John Murdock, Contra Costa County Forensic Services Division
This presentation is designed with forensic management in mind as an "executive summary" of the historical and current ability of the firearm and toolmark identification community to respond to Daubert challenges in general, and with emphasis on its response to the critical issue of scientific testability. The topics to be covered are as follows:
- Daubert legal challenges including significance to the firearm and toolmark identification community and the impact on laboratory management overseeing this kind of casework;
- Brief historical background of consecutive matching striae (CMS);
- CAC Northern California Firearms Study Group CMS survey;
- Common objections to the use of CMS in casework;
- Benefits that management can expect from examiners adopting CMS in toolmark identification