116th SEMI-ANNUAL SEMINAR (Fall 2010)
CALIFORNIA ASSOCIATION OF CRIMINALISTS
October 3-7, 2010
THE FABRIC OF OUR LIVES: EXTRACTING TRACE DNA FROM NINHYDRIN-SPRAYED COTTON FIBERS
Jumana Latif and Wellington Onyenwe (presenting), Alameda County Sheriff's Office Criminalistics Laboratory
This experiment set out to possibly validate the usage of ninhydrin on clothing, or in this case, white t-shirts. The scenario that this would be applicable to would be that of a physical altercation such as a rape, robbery, etc. The goal was to retrieve typeable DNA from clothing. Brand new white t-shirts were used for the experiment; one control shirt and one experimental shirt. Subject A touched the control shirt in six pre-marked areas on the front, while subject B touched six pre-marked areas on the back of the shirt. The experimental shirt was handled by both subjects vigorously and violently to simulate a fight. Subject A handled the front, whereas subject B handled the back. Both shirts were then sprayed with ninhydrin and allowed to develop.
Six cuttings and six swabs were sampled for DNA from the control shirt and seven cuttings were sampled from the experimental shirt. Out of a total of nineteen samples, front and back, three samples from the experimental shirt and six samples from the control shirt gave trace quant results. The quant range was .0011-.015 ng/μl. The remaining ten samples gave no quant results. The samples that had trace results were amplified using the polymerase chain reaction method, yielding partial DNA profiles.
EXTRACTION OF DNA FROM HUMAN LIP PRINTS
Vivien Lee, California Department of Justice Forensic Services Jan Bashinski DNA Laboratory
Lip prints are commonly found on drinking glasses, paper napkins and duct tape (such as that used to bind a victim). Multiple studies have confirmed the uniqueness of human lip prints, and their individualizing characteristics have been used to identify suspects, much like fingerprints. However, there are caveats. Since lips lack sweat and sebaceous glands, the use of conventional fingerprint powders (that cling to bodily oil residue) and ninhydrin (which reacts with amino acids in sweat) have limited success (Castello, 2002). Distortion, pressure, directionality, whether the mouth is closed or open, and how the lift tape is handled during evidence collection can produce different prints from the same person. Due to these caveats, the extraction of DNA from lip prints may be a preferred technique to the visual identification of lip prints.
This research sought to determine the feasibility of DNA extraction from lip prints on glass cups and paper napkins, both with and without contamination with lipstick or fingerprinting powder. The study also tested whether an organic or silica-based extraction method was more suitable, what PCR conditions provided optimal amplification, and what effect, if any, contamination and age had on STR typing using the Applied Biosystems™ AmpFlSTR® Identifiler PCR Amplification Kit.
AUTOMATING DNA EXTRACTIONS UTILIZING THE DNA IQ™ CASEWORK PRO KIT ON THE MAXWELL 16® INSTRUMENT
Cami Green, Promega
The Maxwell 16® instrument offers forensic laboratories fast and reliable extractions of casework type samples such as blood stains, semen stains, cigarette butts, and touched samples. Automating the DNA extractions can dramatically reduce the hands-on bench time and potential pipetting variability. The new DNA IQ™ Casework Pro Kit for the Maxwell 16® instrument has been redesigned and optimized for improved DNA yields. This presentation will summarize the extraction performance of the DNA IQ™ Casework Pro kit which utilizes the unique DNA IQ™ Resin that eliminates PCR inhibitors and contaminants frequently encountered in casework samples. In addition, the presentation will include comparison testing data using the organic extraction protocol and other commercially available extraction methods.
OVERVIEW OF THE COLD HIT OUTCOME PROJECT (CHOP)
Eva M. Steinberger, California Department of Justice Forensic Services Jan Bashinski DNA Laboratory
The Cold Hit Outcome Project (CHOP) is an extension of the CAL-DNA Data Bank. It is an interactive database designed to follow the course of progress of offender hits and case-to-case matches. The CHOP database can also be used as a tool for the management of unsolved DNA cases. CHOP will eventually serve as a clearinghouse for state-wide information on DNA Data Bank hits and unsolved DNA cases.
CHOP was developed by the California Department of Justice (DOJ), Bureau of Forensic Services (BFS) in partnership with the Western States Information Network (WSIN). The CHOP database is located within WSIN's Regional Information Sharing System Network (RISSNET). On September 15, 2009, the CHOP database was deployed to a limited group of agencies participating in the pilot version of CHOP; additional participants are being added on a continuing basis. To date the CHOP users group has grown to 270 individuals in 13 counties. Presentation to include CHOP benefits, restrictions, database requirements and how to become a CHOP user.
INTEGRATION OF THE AUTOMATED PREPFILER™ EXTRACTION SYSTEM INTO AN AUTOMATED HIGH VOLUME CASEWORK SCHEME
Robert Binz, Orange County Crime Laboratory
Over the course of a year, the Orange County Crime Lab (OCCL) receives thousands of burglary cases, containing tens of thousands of samples. As a result, the DNA lab has decided to incorporate the automated PrepFiler™ extraction system, developed by Applied Biosystems™, into their DNA processing scheme to handle the increased caseload. This system, which utilizes the Tecan Freedom EVO® robotic liquid handling system, will be used to extract DNA from samples collected from high volume property crimes. In addition to blood and cigarette butts, these samples include swabs of handled items, which tend to contain lower quantities of DNA. In order to accomplish the validation rapidly and to involve less OCCL analyst time, the services of an outside vendor were utilized. The automated extraction system, in conjunction with other downstream robotic systems, will be one of the final steps in completing our high volume casework line and is anticipated to greatly reduce the amount of analyst time in processing samples. This presentation will illustrate the steps needed to prepare for this validation, the validation process itself, the pros and cons of using an outside validation team, and the overall benefit of automation for use in processing high volume property crime evidence.
MICRO-TOTAL ANALYSIS SYSTEMS FOR NUCLEIC ACID ANALYSIS
Ivan K. Dimov (Presenting) and Ben Ross, DiAssess, Department of Bioengineering, University of California, Berkeley
Compared to conventional macro-scale laboratory methods, integrated Micro-total analysis systems (μ-TAS) offer potential advantages of lower cost, higher speed, smaller sample and reagent volumes, and automation of all processes from sample preparation to analytical result: the "sample-to-answer" concept. However, potentially the most important consequences of successfully implementing μ-TAS are the enhanced assay reliability with less contamination and precise quantitative results relative to classical analytical procedures. In this presentation we will examine applications of μ-TAS systems in genetic analysis, specifically forensics sample-to-answer systems and the use of isothermal nucleic acid amplification. Due to the high robustness and low requirements of Loop-mediated isothermal amplification (LAMP) a novel set of devices for multi-disease point of care are being developed. This technology was initially leveraged for the combined diagnostics of HIV and TB, diseases that combined kill about 5 million people per year. LAMP amplification is also combined with a novel aptamer desorption sensing technique to enable the highly sensitive detection (down to 50 bindings) of protein biomarkers with visual readout. Finally we will conclude the talk with potential future applications of this technology for portable analyses systems that produce onsite results and eliminate the need for sample collection, transportation and preservation and reduce potential contamination and the required sample volumes.
THE 'INVESTIGATOR QUANTIPLEX KIT' - A NOVEL FAST AND ACCURATE REAL-TIME PCR QUANTIFICATION ASSAY - COMBINED WITH AUTOMATED REACTION SETUP FURTHER STREAMLINES THE FORENSIC WORKFLOW
Scott Burrows (Presenting), Francesca Di Pasquale, Stefan Cornelius, Margaretha König, Mario Scherer, Claudia Schmid, Claudia Dienemann, Lars Brochmann, Anke Prochnow, Thomas Schnibbe and Holger Engel QIAGEN GmbH, QIAGEN Strasse 1, 40724 Hilden, Germany
Commonly short tandem repeat (STR) analysis is performed for human identification, although alternative approaches like the analysis of deletions and insertions (DIPs) have recently become commercially available.
However, these multiplex assays used for human identification are complex systems that require a defined range of DNA template input. Accuracy of quantification, even for samples of low concentration, and an assessment of the presence of PCR inhibitors are key requirements to ensure successful genotyping on the first pass.
Quantitative real-time PCR has become the standard method for quantification of DNA in forensic samples. However, there is a need for advanced solutions further streamlining the forensic workflow by increasing the accuracy of the quantification results, especially for samples of low concentration, and reducing the time for analysis by faster procedures. Therefore we developed a novel human DNA quantification assay - the Investigator Quantiplex Kit - which provides fast and accurate quantification of human DNA in forensic database and casework samples. The assay provides sensitivity down to less than 2 pg/reaction (preliminary data - developmental validation of limit of detection still ongoing), with highly accurate quantification in linear range of standard curve of less than 10 pg/reaction. Detection of PCR inhibitors is ensured by a balanced internal amplification control. The Investigator Quantiplex assay makes use of PCR fast cycling technology allowing fast time to result. When used with the Rotor-Gene Q Real-Time PCR system, quantification can be performed in less than 50 minutes.
Automation of laboratory procedures is gaining more and more importance in the forensic laboratories, saving time for routine procedures like PCR set-up and performing dilutions while also limiting user errors.
The QIAgility system is a bench top instrument allowing automation of routine procedures in the forensic PCR laboratory workflow, involving PCR setup for real-time PCR based DNA quantification. The instrument also allows automated adjustment of DNA concentration of forensic samples to a specified concentration making use of real-time PCR based quantification results. Additionally, the reaction setup of the multiplex human identification assay, either STR or DIP based, can be performed by the instrument, as well as preparing samples for CE.
The combination of the new human DNA quantification assay with advanced instrumentation like the Rotor-Gene Q significantly shortens time to results in forensic DNA quantification with increased accuracy and sensitivity. When combined with the QIAgility instrument, the workflow can be further streamlined and time consuming and error-prone manual interactions are minimized.
TOOLS FOR ESTIMATING THE WEIGHT OF EVIDENCE FOR DIFFICULT DNA PROFILES
Kirk E. Lohmueller, PhD; Norah Rudin, PhD; Keith E. Peterson Inman, M.Crim. University of California, Dept. of Integrative Biology; Forensic DNA Consulting; California State East Bay, Dept. of Criminal Justice Administration
One of the most difficult issues with which forensic DNA analysts currently struggle is the interpretation of complex samples. In particular, low template (LT) samples, or worse yet mixtures including LT components, present a particular challenge to the practitioner in estimating the weight of such evidence. Many laboratories employ a combined probability approach, e.g. CPI, CPE, RMNE. Various iterations of those calculations include using peak heights or information about a known intimate contributor to attempt to deconvolute a mixture. Another common approach is to employ some variation of "2p" to estimate the statistical weight of an observed single allele.
The advantage to such approaches is mostly that the calculations are relatively easy. Another proffered advantage is that they generally tend to underweight the evidence, and hence are described as "conservative." In fact, a combined probability statistic, in particular, potentially discards much of the information in a sample, artificially reducing the weight of such evidence. However, underweighting the evidence is not necessarily "conservative" in the context of the case. For example, the defense may have an alternate suspect who could be a minor contributor to a sample, in which case a greater evidential weight would be more beneficial to the defendant. Situations also exist in which a combined probability statistic can actually overweight the evidence, in particular if the H0 (primary) hypothesis (which may or may not be the prosecution hypothesis) requires allelic drop-out. In the extreme, a reference subject can actually be falsely included by assuming that the impact of potential drop-out is neutral.
Most analysts understand that a combined probability approach is not the optimal method for estimating the statistical weight of the evidence, but perceive roadblocks in implementing the more sophisticated and powerful approach inherent in a likelihood ratio (LR). The two main challenges are: 1) lack of an accessible, inexpensive, user-friendly computer program, and 2) a reliable method to estimate allelic dropout (DO) probabilities. In this workshop we will present solutions to both of these issues. In particular, we will review the open source R-code program written by Dr. David Balding(1) and freely available for download on his web site(2). We will discuss a current project to add a user interface to the R-code that would make it more accessible to the average analyst(3). We will also present ongoing work to estimate the probability of drop-out using a method similar to that suggested by Tvedebrink et al.(4)
Specific examples that demonstrate the utility of a LR approach in assisting the analyst to provide an accurate and reliable estimate of the weight for a difficult profile will be presented.
1. Balding, D.J., Buckleton, J. Interpreting low template DNA profiles. (2009)
Forensic Science International: Genetics 4, 1-10.
2. www.zebfontaine.eclipse.co.uk/djb.htm; scroll down to "software"
3. Partially funded by a McLaughlin grant
4. Tvedebrink, T., Eriksen, P.S., Mogensen, H.S., Morling, N. (2009) Estimating the probability of allelic drop-out of STR alleles in forensic genetics. Forensic Science International: Genetics 3, 222-226.
SPECIES DISCRIMINATION OF WHITE-TAILED DEER AND MULE DEER BY MICROSATELLITE MARKERS
Megan Caulder, California Department of Justice Forensic Services, Jan Bashinski DNA Laboratory
Wildlife forensic casework often requires species identification prior to individualization. Particularly challenging cases may require discrimination of phylogenetically closely related species with overlapping geographic distributions, such as North American deer. We screened deer (Odocoileus sp.), cattle (Bos Taurus), and elk (Cervus elaphus) nuclear microsatellite DNA loci for differences in allele characteristics to develop a panel that would discriminate between whitetailed deer (O. virginianus) and mule deer (O. hemionus). Using our panel of nine microsatellite loci and one sex-typing marker, we established population data for 237 deer spanning the states of Washington, Wyoming, Montana, Colorado, and Arizona. All of the individual species assignments using this autosomal DNA data, and an analysis using the software GeneClass2, correlated with their reported assignment based on morphology. These results provide a new tool for forensic poaching cases involving deer species identification.
THE EVOLUTION OF FORENSIC DNA TECHNOLOGIES
Brad Dixon, Applied Biosystems Part of Life Technologies
This presentation will discuss Applied Biosystems' role in the development of DNA technology for human identification applications. As forensic analysts are presented with an increasing number of sample submissions from a wider range of sample types, Applied Biosystems' forensic technologies have expanded to address the complete DNA analysis workflow, from extraction to data analysis.
The Prepfiler™ Forensic DNA Extraction kit chemistry has been developed to yield high quantity and high quality DNA for low to high throughput workflows. The Automate Express™ instrument employs the Prepfiler kit chemistry in an easy to use, flexible benchtop system with a convenient 13 sample throughput for casework laboratories. The Quantifiler ® Duo DNA Quantification kit is a powerful predictive tool allowing analysts to detect the presence of male:female DNA mixtures, indicate the presence of inhibitors and determine the quantity of total human and male DNA.
Early advancements in short tandem repeat STR kit development included the application of 5-dye technology and mobility modifiers to accommodate more loci in a smaller size range, the development of enhanced buffer systems to overcome inhibitors of the polymerase chain reaction (PCR) and the launch of the AmpFlSTR® Minifiler™ kit, the first commercially available kit to reduce the amplicon size enabling better amplification of degraded DNA.
We will discuss the recent optimization of the Identifiler ® kit chemistry to address the specific requirements of casework and databasing laboratories. To relieve the data analysis bottleneck, the GeneMapper® ID-X software has been developed as an expert system for analysis of single source databasing samples with enhanced features such as the mixture analysis tool to aid in the interpretation of casework samples. These technology advancements and efficiency improvements are driven by global adoption of DNA methods and rapidly expanding worldwide databases. Forensic analysts seek methodologies designed to increase productivity, reduce time to result, maximize the quality of results obtained and decrease costs.
Improvements to each step of the workflow: extraction, quantification, amplification and data analysis have been made to increase the efficiency of forensic DNA sample processing.
THE IMPLICATIONS OF SUPPRESSED, FALSIFIED OR UNDISCLOSED LAB INFORMATION IN LITIGATION: A REVIEW OF THE LAW AND PRACTICALITIES
John Philipsborn, Attorney
This presentation will use concrete examples such as the "SFPD Lab 'Scandal' " and the DNA section issues in Houston, to review the legal obligations of the prosecution to provide exculpatory or impeaching information under the Brady doctrine, and the practicalities of the way that lawyers knowledgeable about such litigations approach these sorts of issues.
This presentation will be given by a lawyer who has been involved in such litigation in various parts of the country.
EXPLORATION OF GASOLINE-POOL TABLET MIXTURES
Katherine Hutches, Bureau of Alcohol, Tobacco, Firearms and Explosives
Hypergolic, or self-igniting mixtures are potentially used as more subtle means of ignition for incendiary devices. In online forums such as the Jolly Roger, there are references to a new type of hypergolic mixture consisting of gasoline and pool chlorinator, which supposedly form an instant fireball on combination. The effectiveness of this mixture for energetic self-reaction, as well as the effects of the mixture on fire debris analysis, will be discussed.
Paul Hora, Alameda County Deputy District Attorney
A presentation on the Hans Reiser Murder case. The murder occurred on September 3, 2006. Nina Reiser, Hans' estranged wife, was initially reported as a missing person, but the missing person investigation resulted in Hans Reiser's arrest for murder on October 10th, 2006. Nina's body was never located and the case proceeded to trial. The jury convicted Hans Reiser of 1st degree murder. Following his conviction, Hans Reiser agreed to disclose the location of Nina's body in exchange for a plea of guilty to 2nd degree murder. The case involved an extensive and lengthy investigation including a substantial amount of criminalist work. My presentation will provide an overview of the murder case, including but not limited to: the investigation, forensics, evidence collection, the trial and the body recovery.
THE CONFOCAL MICROSCOPY ANALYSIS OF TEN CONSECUTIVELY MANUFACTURED RUGER P95 BREECH FACES
Todd Weller, Oakland Police Department Crime Laboratory
This presentation will show the results of confocal microscopy analysis of ten consecutively manufactured pistol slides. Confocal microscopy allows one to collect and numerically record three dimensional topography. The purpose of this study was to use this technique to study test fires recovered from pistols with consecutively manufactured breech faces.
This study provides numerical, objective validation that consecutively manufactured firearms can be distinguished from each other using the marks left on fired cartridge casings. Additionally, this study provides objective validation that cartridge cases can be associated to a firearm through the comparison of these same markings.
EXAMINING 3D TOPOGRAPHY RELATIONSHIPS OF STRIATED MARKS ON BULLETS USING THROUGH FOCUS MICROSCOPY
Jessica Morning, University of California, Davis Forensic Science Graduate Group
After attending this presentation, attendees will have an understanding as to the current research on striated marks within the land impression of bullets and efforts to reproducibly record them in a quantitative way. Previous work has focused on using confocal microscopy to record the surface of the land impressions and then make comparisons based on cross correlation functions of the entire surface. It was determined that this method involved too much computing power for it to be feasible as a new national searchable database. This study is the first step in developing a simpler record of the striations for each land impression that can be used in a database on an average desktop computer. We asked what is the topographical nature and relationship of striated marks on bullets within the land impressions? There is an expectation that the stria will start, stop and drift as you move toward the nose of the bullet. Through focus microscopy uses layered multiple image slices to render three dimensional images in full focus along with height data. We are using this technique to make multiple comparisons along the length of the bullet surface, specifically examining profiles that cut across the striations. From these profiles, the positions of the maximum heights, corresponding to peaks or light regions in an image, and minimum heights, signifying valleys or dark regions in an image, are to be ascertained. These positions are recorded for comparison. In this way, the variations of the striae within a specified area can be compared to the data collected by a firearms examiner using a bridge microscope. The ultimate goal is to determine the position and total number of profiles required to capture all or the vast majority of the variation within the area.
FORENSIC BREATH ANALYSIS LIE DETECTION: A NOVEL IDEA
Michael K. Hemp
In 1994, I had a conversation in a Carmel cottage with the president of a high tech firm located in Mountain View, California. He explained to me in fascinating detail some of the capabilities of an emerging technology his company had acquired, utilizing new GC-MS techniques. Its capabilities stunned me and as I later thought of all the chemical processes and ultratrace-level compounds that could be definitively analyzed, it struck me: "What if that most exquisite electrochemical machine, the human brain, could be monitored to identify a thought process using GC-MS breath analysis? Everyone knows that various "breathalyzers" can accurately identify compounds in the breath. What other evidence is there in the bouquet of chemical compounds expelled in the human breath? Could there be an unexplored record of our human behavioral chemistry in that gaseous chemical exhaust? Could it identify the chemistry of the human lie?
Had the hypothesis that GC-MS/LI-MS could identify the molecular biochemical signature for the human lie emerged from a laboratory, it would surely be far advanced in feasibility and development-and probably highly classified. However, since it emerged from a historian's fertile mind, it is neither widely known nor accepted as yet in forensic circles, (though SRI has shown particular interest).
Earliest support for the premise of a breath and skinpore analysis lie detection technology came from an expert source: leading forensic biochemist, Dr. Brian Andresen-former director of the Forensic Science Center at Lawrence Livermore National Laboratory. In the Epilogue of The Nadjik Pheromone he writes:
In The Nadjik Pheromone, Michael Hemp presents a fictional, robotic system-a computer guided gas chromatography-mass spectrometry (GC-MS) instrument able to detect specific, universal biological molecular markers for the human act of lying. While monitoring breath and skin utilizing specialized polymer concentrators for deception compounds, this new GC-MS lie detector technology literally "smells the truth" in gaseous chemical pheromone-like human effusion.
What is new today in the premise of "The Nadjik Pheromone" is that the search for the specific bio-chemical fingerprints for the human act of lying is a real goal. The futuristic "Nadjik Pheromone" lie detector technology of breath and pore analysis technology may soon be a reality for all of us."
"The Nadjik Pheromone" began as a screenplay in 1994; in 2008, it became a novel: an American war correspondent's passion to end genocide and crimes against humanity. A March 2010 presentation of "The Nadjik Pheromone" to the ACS San Francisco conference at Moscone Center heralded the initial awareness and interest by the forensic science community. That presentation prompted its nomination for a subsequent presentation to the CAC.
The application of an irrefutable and scientifically verifiable lie detection technology has implications of unprecedented historic and global consequence. Therefore, this presentation will center on the sincere proposal to the interested scientific community to apply their newest pre-concentration techniques to "fast GC-MS analysis" in a search for key chemical fingerprint profiles that can point to a "real" non-fictional lie detection technology.
CHARACTERIZATION OF SURFACE-MODIFIED FIBERS BY X-RAY PHOTOELECTRON SPECTROSCOPY
X-ray photoelectron spectroscopy (XPS) is a method of surface analysis. In XPS a surface is irradiated with a monochromatic x-ray beam and the number and kinetic energy of escaping electrons is measured. With most surfaces examined the depth of penetration is no more than 10 nm, with most of the signal coming from within 6 nm or less. Because the binding energies of electrons at various energy levels for the different elements are known, XPS is a quantitative method of elemental analysis for surface layers. However, because the binding energy of an electron in an atom is slightly affected by the atom's oxidation state as well as to which other atoms it is bonded, XPS also provides information about the chemical state of the elements in the sample.
INHALANTS AN UNDETECTED DANGER: CREATION AND VALIDATION OF A HEADSPACE GAS CHROMATOGRAPH METHOD FOR THE ANALYSIS OF HYDROFLUOROCARBONS IN BLOOD
Chelsea Carter, San Diego PD, Forensic Chemistry Unit
This presentation will discuss the research, development, and validation of an inhalant detection method now being utilized at the San Diego Police Department. Social implications of inhalant abuse such as inhalant abuse in children, adolescents, and adults, the prevalence of inhalant abuse in our military, as well as the physiological effects of the drug will be discussed.
Inhalants are considered any volatile substance whose chemical vapors can be inhaled to produce psychoactive effects. They are considered a gateway drug, much like alcohol and marijuana, which can lead to lifetime drug use. In a national 2008 study, it was noted that there were twice as many new inhalant abusers as there were cocaine abusers; and inhalant abusers covered a much larger age range. Accessibility is partly to blame for this rise in abuse as there are over 1,000 commonly sold products that are cheap, legal, and toxic. An increase in inhalant based arrests led to the development of a method that would detect commonly abused inhalants.
The method created accurately separates and detects 1,1- Difluoroethane, 1,1,2-Tetrafluoroethane, Ethylene Dichloride, and Toluene. This method was recently utilized in a manslaughter case that is currently being adjudicated. A case discussion will be included in this presentation.
SUSTAINED COMBUSTION OF BODIES: SOME OBSERVATIONS
John D. DeHaan, Ph.D., President Fire-Ex Forensics, Inc.
When a body is involved in a fire, it is often thought of by fire investigators as a passive target of heat and flame. In some cases, however, it becomes involved as a fuel package, contributing flames and heat of its own. It is, in rare cases, the major fuel package supporting flaming combustion in the vicinity of the body for much longer times than other fuels nearby. This paper will explore the combustion of human cadavers and similar large-animal carcasses as they burn in sustained fire environments. Previous tests have explored the thermal response and fuel characteristics in intense fires of relatively short exposure times. The tests discussed here will concentrate on fire tests where the body was the primary fuel package, but will also compare the results of fire exposures in well-fueled, well-ventilated fires in both vehicles and furnished rooms. These tests focused on long duration fires involving both intact human cadavers and torsos and whole pig carcasses of various sizes. Test fires included both fully involved vehicle and compartment fires, as well as non-accelerated, long-duration fires involving only the bedding and clothing (in the manner of typical accidental deaths where a dropped match ignites such materials).
It was observed that bodies are a complex fuel package offering several different fuels whose behavior and thermal properties vary a great deal. The subcutaneous body fat presented in nearly all bodies is, by far, the best fuel present. For it to contribute, however, the dermal layers have to shrink and split (from external fire exposure of several minutes duration),
the body fat has to render out, and be absorbed by a porous, rigid substrate (often the charred remains of the bedding, clothing, upholstery, carpet or wood floor). The combustion then takes place where the body fat burns on the porous wick as a flaming fire. Fires of 20-60 kW heat output have been observed in tests where the body was the main fuel source. The flaming combustion of the body has been observed to be sustained for 4 to 8 hrs.
The limited size of the fires means that radiant heat to nearby target surfaces is insufficient to ignite them, and usually only enough to scorch or soften them, and that the air supply needed to sustain the fire is very modest. A sustained fire fueled by a body is capable of burning for extended periods of time without spreading to nearby fuels, unless those fuels are in direct contact with the small flames produced. Such fires can be maintained in ordinary rooms, even with doors and windows closed. The small flames produced are capable of desiccation, charring, and calcination of exposed bone, with eventual collapse of exposed bony structures. Muscle and
collagenic components will be charred and burned away if they are exposed to the direct flames. This paper will demonstrate the destructive effects of fire under a variety of conditions and address some of the mythology and misconceptions about bodies in fires.
CASTRO VALLEY JANE DOE
Greg Landeros, Detective, Alameda County Sheriff's Office
Investigators will discuss the three year investigation into the murder of a sixteen year old girl whose decomposed body was found behind a local restaurant in Castro Valley, CA. The case led investigators to Mexico on three separate occasions as they utilized forensic artists, forensic sculpting and DNA to eventually learn the identity of the victim, Yesenia Nungary Becerra and her killer, Miguel Angel Castaneda.
EVALUATING THE PROBATIVE VALUE OF SEXUAL ASSAULT EVIDENCE COLLECTED FROM SUSPECTS
Chani Sentiwany, Oakland Police Department
The objective of this study was to determine the probative value of collecting evidence from the suspect in a sexual assault. A retrospective study was designed to review information gathered from all analyzed suspect sexual assault exams from 2000 through 2009 at the Oakland Police Department. This included review of 49 suspect sexual assault kits collected by Highland Hospital in Oakland prior to February 2006 and 57 kits collected by VBS Services after February 2006. This study focused on the laboratory results from analysis of the penile swabs, scrotal swabs, and finger swabs. Data results will focus on the probative nature of each type of swab.
Probative value was evaluated based on the percentage of the victim's DNA profile obtained. This talk will provide general descriptive information on age, sex, and ethnicity of both victim and suspect. Post assault interval results and trends will be provided. Data on the correlation of presence or absence of epithelial cells and obtaining foreign DNA will be discussed. A few illustrative cases will be described.
A RETROSPECTIVE STUDY OF 148 SEXUAL ASSAULT KITS
Shannon Cavness, Oakland PD Criminalistics Division
The objective of this study was to determine if there are predictors of yield within the forensic medical report with respect to DNA profiling. A retrospective study was designed in which 148 sexual assault cases were selected for review from approximately 350 cases occurring between August 2003 and October 2007. In all cases, evidence was collected by medical practitioners at Highland Hospital in Oakland California and examined by criminalists at the Oakland Police Department (OPD) Criminalistics Laboratory. All cases assigned the penal code: 261 completed by laboratory criminalists within a specific time frame were examined for this report. No other penal code cases were utilized for this study. These cases include only sexual assault examination of victims aged 14 years and older. Of the 148 cases, 93 cases (63%) yielded a complete probative profile, a complete profile being defined as obtaining all alleles at all attempted loci for the specific amplification kit utilized during the processing of the case.
It was determined that if sperm were observed by hospital staff during microscopic examination of the vaginal slide, they would be seen by laboratory staff 100% of the time. The inverse was not found to be true.
N-ACETYLBENZOCAINE: FORMATION VIA TRANSACETYLATION OF BENZOCAINE AND ACETYLSALICYLIC ACID IN A COCAINE EXHIBIT.
Minh C. Nguyen, Forensic Chemist, DEA Western Laboratory
N-Acetylbenzocaine was recently identified in an illicit cocaine HCl exhibit which also contained salicylic acid and traces of acetylsalicylic acid, and benzocaine. This presentation discusses the analysis and characterization of N-acetylbenzocaine, as well as its transacetylation synthesis pathway. Supporting analytical data from gas chromatography/mass spectrometry, gas chromatography flame ionization detection, Fourier-transform infrared spectroscopy, and Fouriertransform nuclear magnetic resonance spectroscopy are presented.
SURVEY OF SEXUAL ASSAULT EVIDENCE KITS
Jennifer Riedel, Forensic Scientist, Oregon State Police, Springfield Forensic Laboratory
Statistics regarding the results of Sexual Assault Forensic Evidence (SAFE) kit analyses would be helpful in educating law enforcement and medical personnel on sexual assault response efforts. This study evaluated the incidence of semen positive results from 469 rape victims' SAFE kit samples. The kits were submitted to two Oregon State Police laboratories between 2003 and 2005. Information from officer's reports and victims' statements was also collected. Overall, 46% of the 469 victims had at least one sample that was positive for semen. As the time elapse between assault and sample collection increased, the probability of a positive result decreased. That probability leveled out to approximately 26-27% after 36 hours, with a spike of 40% in the 48-60 hour range. Additional conclusions evaluated positive results based on body locations reportedly penetrated, condom usage, reported voluntary intercourse, and other factors. Instances when both vaginal and cervical samples were collected and yielded different results were also evaluated. This study determined that while the victim's statement remains a good trigger for which samples should be collected, they should not be solely relied upon. Vaginal and cervical samples should both be collected when possible.
CASES EXAMPLES: LAB, CORONER, AND PD WORKING TOGETHER WELL
Dr. M.J. Ferenc, Forensic Pathologist
The Coroner is often an overlooked or marginalized component in a death investigation. The usual presumption is that the Coroner does the autopsy and then should not be heard from until the case reaches a courtroom. Two cases are given as examples of how the Coroner, the crime lab, and police can work together assembling criminal cases that they probably could not have put together otherwise
THE RECOVERY OF DNA ON IMPROVISED INCENDIARY DEVICES (MOLOTOV COCKTAILS) UTILIZING VARIOUS FIRE SUPPRESSION TECHNIQUES
Lauren Buban(1) (presenting), John Jermain(2) (presenting), Clarissa Trogdon(1), and Steven B. Lee(1);
(1) San Jose State University, (2) Bureau of Alcohol, Tobacco, Firearms, and Explosives
The use of improvised incendiary devices (weapons) against property and persons for various reasons has been an increasing problem in urban environments. Improvised incendiary devices are inexpensive to make and easily constructed. However, the damage inflicted by such a device is immeasurable and can cause serious physical injury and/or death. Of all improvised incendiary devices that can be constructed, the Molotov cocktail is the most common. Molotov Cocktails most commonly consist of a breakable glass container, an ignitable liquid (usually gasoline) and a lighted wick. The wick can consist of many different materials (examples: cloth or paper). The effects of a Molotov cocktail are maximized after the device is thrown against a hard surface, thus breaking the container and causing the liquid to ignite (from the lighted wick). While Molotov Cocktails are inexpensive to make and easy to construct, from a fire investigation perspective they can be easy to detect at a fire scene. Portions of the bottle bearing the most information about its origin, the neck with its labeling and the base with its cast-in-production data are the pieces of the bottle most resistant to mechanical and fire damage and usually survive intact. Identification of individuals who manufacture and use Molotov cocktails is of interest to law enforcement. Previous research conducted by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) has shown that DNA can be successfully recovered from the remains of a charred Molotov cocktail. While this is promising information, many Fire Investigators have speculated that perhaps the fire suppression techniques could be a factor in the DNA recovery.
In this study two samples sets of Molotov cocktails were prepared in replicate and were either ignited and unignited. Both sets were deployed at the Milpitas FD Training Tower. The two sample sets were further divided into six subsets where either they were allowed to self extinguish or were treated with different suppression techniques; water, foam, CO2, dry chemical, and Met-L-X. In each subset, 50 μl of saliva were deposited onto three bottle lips, and 50 μl of TE on one bottle lip, for a total of forty-eight bottles. Two sequential wet swabs were used to collect DNA from each bottle lip, resulting in a total of ninety-six swabs. A phenol chloroform organic extraction was used to extract DNA, and quantitative PCR analysis was performed in duplicate to assess both inhibition and recovery. Amplification results with Identifiler and Identifiler plus without and with amplification enhancers will also be evaluated. Separation and detection of the amplicons will be performed by capillary electrophoresis (ABI 310). Qualitative and quantitative analysis of peak heights and balance will be conducted using Genemapper ID to compare recovery and inhibition from different extinguishers on control (unignited) and test (ignited) samples. Recovery of 190 ng of DNA was achieved from replicate 50 μl aliquots of liquid saliva. No detectable DNA was observed from negative controls. Preliminary results on control samples (self extinguished) indicate a higher recovery from the Molotov cocktail bottles that were unignited versus the ignited samples. DNA recovery was inversely proportional to the time it took to self extinguish. The recovery of DNA from the second wet swab was lower and in many replicates resulted in no detectable DNA indicating that taking a second swab may not be needed. This presentation will demonstrate the effects various fire suppression techniques have on the recovery of DNA from Molotov Cocktails.
USING THE NEANDERTAL GENOME TO UNDERSTAND RECENT HUMAN EVOLUTION
Richard Green, University of California, Santa Cruz
Recent technological advances have enabled large-scale retrieval and sequencing of DNA from our closest relatives, the extinct Neandertals. To detect regions of recent positive selection in humans, to better understand our relationship to Neandertals, and to eventually understand Neandertal-specific biology we recently embarked on a project to sequence the complete Neandertal genome. To achieve this goal, several technological advances were required in recovery and identification of ancient DNA sequence from fossil bones. Having have now accumulated and analyzed these data to address questions about recent human evolution. From these data, we estimate an average Neandertal-human genome divergence of about 800,000 years and a population split time of about 300,000 years. The latter estimate rules of one model of hominid evolution, namely that Neandertals are the descendants of H. heidelbergensis. Because Neandertals share some of the genetic diversity still extant within human populations, they make an ideal genetic comparison to test for recent positive selection in humans. Comparing Neandertal with human diversity, we find regions where little or no variation is shared with Neandertals. These are thus candidate regions for evolutionary changes that are the genetic basis of being fully modern humans.