124th SEMI-ANNUAL SEMINAR (Fall 2014)
CALIFORNIA ASSOCIATION OF CRIMINALISTS
October 20-24, 2014
Rohnert Park, California
Jennifer Thompson and Ron Cotton
Jennifer Thompson incorrectly (and unintentionally) identified Ron Cotton as the man who sexually assaulted her. Years later Mr. Cotton was exonerated. Their story is described as "One man's fight for truth. One woman's struggle to recover. Two lives forever connected. A true story of forgiveness and hope". This will be a powerful firsthand account of false conviction and how it affects everyone involved.
CAN WE "SEE" INNOCENCE?
Linda Starr and Melissa O'Connell
Since its inception in 2001, The Northern California Innocence Project (NCIP) at Santa Clara University has won victory for 17 people. In some of those victories forensic science played a pivotal part. Linda Starr, legal director of NCIP, will provide an overview of NCIP's work, and identify some lessons learned from working with forensic scientists, as well as some thoughts for forensic scientists working with NCIP. Staff attorney Melissa O'Connell will then present the NCIP exoneration of Johnny Williams. In Mr. Williams' case, exculpatory biological evidence was inadvertently missed during initial testing. Thirteen years after his conviction, the evidence was re-examined, biological material was discovered and DNA testing proved his innocence. His exoneration demonstrates how re-testing can be critical to uncovering the truth.
TURNS OUT YOU CAN DO PCR IN A BARN: EXCEEDING THE LIMITS OF SCIENCE-A CASE REPORT
Lynne Burley and Norah Rudin
David Camm is a former state trooper who was acquitted and released in October 2013 after his third trial on charges of murdering his wife and two children on September 28, 2000. In 2005, another suspect, Charles Boney, was identified by way of a CODIS hit to crime scene evidence analyzed by the Indiana State Police. Boney was found guilty of the killings, but maintained that he and Camm acted together. In Camm's third trial, the prosecution theorized that Camm either hired or assisted Boney in the homicides; the defense contended that Boney acted alone. A private DNA laboratory, IFS, was hired by the defense to test hundreds of crime scene samples. We were retained by the prosecution team to review the work conducted by IFS. Our critical review addressed various technical issues including accreditation, proficiency testing, validation, case approach, interpretation, and statistics, as well as the overall efficacy of the DNA testing. We will present the various issues that arose in each of these areas, and the ultimate impact of the new DNA analysis on the third trial.
MISSING PERSONS CASES IN MEXICO AND MISSING MIGRANT WORKERS IN THE US
Lance Gima and Eberth Castanon
Workers from Mexico have been traveling to the United States for decades. However, the complexities and arguably failure of the United States' guest worker programs have led to large numbers of Mexican nationals illegally entering the US. In order to avoid being apprehended, migrant workers, once in the US, travel through remote areas of California, Arizona, New Mexico, and Texas to find work. Unfortunately many of these "undocumented border crossers" or UBC's, never reach their intended destinations and their bodies are left in the southern deserts of the United States. Some have called the death of so many human beings in our deserts a humanitarian crisis, however the identification of the found human remains is the responsibility of local coroner's offices and that identification often relies on forensic DNA technology. This presentation will offer statistics regarding the number of human remains found and some estimates as to the cause of death. Additionally, this presentation will include the viewpoint of the Mexican Migrant Worker Identification problem from a DNA Technical Leader from Chihuahua Mexico. The presentation will also summarize a project, funded by the National Institute of Justice that establishes a partnership between five Attorney Generals' Offices in Mexico and the Conference of Western Attorneys General, to acquire reference samples from families of the missing migrant workers in Mexico for analysis in the US with the resultant profiles entered into CODIS. The project also includes the submission of human remains samples found in Mexico thought to be from US citizens, submitted for analysis in the US with resultant profiles entered into CODIS Finally, the problem of database fragmentation in Mexico will be discussed.
THE EGG ROLL DUI DEFENSE: CHALLENGES AND LESSONS AT DUI TRIAL
After attending a holiday social gathering on December 21, 2012, where he had been eating and drinking, the Defendant Coulter Mann was traveling northbound on Highway 101 in far northern California.
At approximately 8:54 PM, and at the moment of receiving a cell phone call, the Defendant drifted into the southbound Lane of Hwy 101, causing a fatal head-on collision with the driver traveling south. Due to the condition of the Defendant's vehicle after the collision, and his broken ankle, he had to be extricated from the vehicle and transported to a local hospital for emergency treatment. His legal blood draw occurred at 10:55 PM and was a 0.20%.
The Defendant was an Assistant Principal at a local middle school and was a very well-liked and well-respected member of the community, as was his entire family. During trial in January of 2014, the Defendant and his two attorneys, one of which was the Defendant's father, and a toxicologist defense expert put forth the defense that the Defendant was not impaired at the time of the collision, and that the cell phone call was the sole cause of the collision. The Defendant had admitted to drinking several high ABV beers and eating food. Of specific interest to the Defense was that the Defendant had consumed 6-7 egg rolls just prior to arriving at his social gathering. According to the Defense the multitude of ingredients in the egg rolls slowed down the Defendant's absorption to the point that he had not absorbed enough alcohol to be at or above a 0.08% BAC at the time of the collision so he was not impaired. The lack of impairment was supported, from the Defense's perspective, by lack of perceived impairment by lay personnel, an emergency medical responder, and the physician at the emergency room where the Defendant was treated for his injuries. The Defense further opined that the impact of the collision caused the quantity of unabsorbed alcohol that was in his stomach to be finally pushed into the small intestine where it was all absorbed by the time of the legal blood draw.
Greg Matheson (CAC Editorial Secretary) and John Houde, (CACNews Art Director) will share with attendees the impressive history of the CACNews and the importance of members and non-members to support the production of the CACNews through technical, editorial and special interest submissions.
SPRING CAC SEMINAR-VENTURA COUNTY
A preview of the upcoming Spring CAC Seminar.
LET'S GET NAKED
Many analysts may rely on biological screening results to determine the next step in their analysis, whether it is taking a sample through the DNA process or stopping testing. In this presentation, interesting results regarding presumptive saliva negative cases will be shared to show one analyst`s life altering experience. Curious as to how other analysts would have processed certain samples, a survey was created and the results will also be shared.
PROGRESS TOWARDS A GELSIGHT-BASED 3D-TOPOGRAPHY IMAGING AND ANALYSIS SYSTEM FOR FIREARM FORENSICS
Ryan Lilien, Todd Weller, Pierre Duez, and Marcus Brubaker
We will present recent results obtained using TopMatchGS-3D, an accurate, fast, and low- cost 3D imaging and analysis system for cartridge casings [1,2]. The prototype scanner incorporates the GelSight retrographic sensor to measure 3D surface topography at a resolution of 1.4 microns per pixel . Last year we introduced the base scanning system and presented initial results obtained using a small dataset. In this presentation we will describe results from a larger dataset of over one hundred 9mm Luger firearms, representing more than 20 firearm manufacturers and 7 ammunition types. The casings represent the types of evidence and test-fires seen in a real-world setting. They contain milled, filed, granular, and striated marks as well as poorly marked casings. Data collection took place both in-house and at several collaborating California crime labs.
Our algorithm's match score is a function of the similarity between the casings' true breech-face impression and their aperture shears. For breech-face impression comparison, automatically identified distinctive features (corresponding to informative microscopic toolmarks) are used to match and align two casings. By requiring spatial coherence of matched features, the methodology is able to strongly indicate when two casings were fired through the same firearm. In contrast to cross correlation based methods, feature- based techniques compute the match score using only the portions of the surface identified as informative (ie., the matching microscopic toolmarks). The algorithm compares aperture shears by first extracting the linear shear profile and then aligning two profiles while accounting for baseline correction and warping. The scoring function is a confidence score where each candidate match (pair of casings) is scored based on the likelihood that the two casings were fired through the same firearm. Unlike other systems, the TopMatch score reflects the true confidence of the match. In addition, the system can explain the rationale of its decision, providing interpretability to the match score.
The TopMatch system is able to match casings with high accuracy. True positives (known matches) have extremely high scores while True negatives (known non-matches) have low match scores. There are virtually no false positives (ie. known non-matches mistakenly identified as a match).
 Lilien, Brubaker, and Weller. "Development of a 3D-Topography Imaging and Analysis System for Firearm Identification using GelSight and Feature Based Case Matching." The Association of Firearm and Tool Mark Examiners (AFTE) Annual Training Seminar (Albuquerque), 2013.
 Lilien, Brubaker, Duez, and Weller. "Progress Towards a Novel 3D-Topography Imaging and Analysis System for Firearm Identification, TopMatch-GS 3D" The Association of Firearm and Tool Mark Examiners (AFTE) Annual Training Seminar (Seattle), 2014.
 Johnson, Cole, Raj, and Adelson. "Microgeometry Capture using an Elastomeric Sensor."
ACM Trans. on Graphics, Proc. of SIGGRAPH, 30:46:1-8, 2011.
3D LASER SCANNING FOR CRIME AND ACCIDENT RECONSTRUCTION
3D Laser Scanning has revolutionized all phases of accident and crime reconstruction. The Documentation of physical evidence is now so accurate and complete that experts can work directly with the 3D Working Model years after the fact as if they were working in the crime scene itself. Measuring millions of data points in mere minutes, a modern 3D Laser Scan is capable of capturing every inch of a scene with precision and detail sufficient to locate the smallest evidence.
A typical scan contains approximately 10,000,000 data points - a level of detail akin to having the entire scene and all the physical evidence extracted and delivered to the experts lab for thorough and exacting analytical forensics. Harnessing these rich datasets with the analytical power of modern computers allows unparalleled depth of Analysis. From determining the velocity of vehicles involved in accidents, deriving critical values from video footage and scene photographs to exacting line of sight calculations and ballistic trajectory trace back, the 3D Working Model provides the expert with a toolset based upon physical evidence that was previously unavailable.
One of the fastest growing areas of growth is the use of the 3D working Model to analyze opposing expert's conclusions and opinions. Being able to plug the underlying assumptions back into the 3D Working Model allows the expert to determine how well, or not, the results match the physical evidence.
Once the dataset has been utilized to complete a thorough investigation and derive fact-based conclusions supported by the physical evidence, the final stage of the process also benefits greatly from the underlying 3D Working Model. The Visualization of the dataset and the conclusions via 3D computer animation and simulation allows the expert to present their findings in a clear, compelling manner to the trier of fact. Using the laser scan data directly in the visualization provides a level of realism and accuracy that far exceeds what was possible before. In addition to being visually compelling in its own right, the scan data gives the expert the opportunity to animate over the exact same dataset upon which their calculations were performed. This increases the accuracy of the final visualization, eliminating the need to resort to mere illustrations and elevating the animation to a true engineering visualization. This ability to maintain the highest level of scene fidelity increases the likelihood that the animation will be admitted into the trial setting and significantly helps combat the CSI-effect often seen in urban courtrooms. Today's juror comes to the trial with an expectation, born from TV and other media that the facts and findings will be presented in a visually compelling manner. Mr. Craig Fries pioneered the use of the 3D Animation and 3D Working Model in forensics in the US. In this presentation he will demonstrate its use via compelling graphics and analyses in all three phases of the reconstruction process, pulling from 20 years of experience and over 1000 cases, all while maintaining a 100% admissions trial record.
SYNTHETIC CANNABINOIDS AND CATHINONES: A CASE STUDY FROM SEIZURE TO TRIAL
Brittany C. Huntington
Synthetic cannabinoids and cathinones, often referred to as "Spice" and "Bath Salts," have plagued law enforcement investigators and controlled substance forensic chemists for over five years. These substances started off as legitimate research chemicals in academia, but were adopted by users for the high they produced while skirting state and federal controlled substance laws. As these substances slowly became controlled substances, suppliers and distributors would quickly switch to different, but similarly structured substances. The new substance would often differ from the controlled substance by only a few atoms, different ring structures, or as positional isomers, which would allow for its distribution without expressly breaking the law.
While the current laws have had difficulty keeping up with the massive number of synthetics being trafficked and identified, most of these compounds could be prosecuted under The Federal Analogue Act. Passed in 1986, the Act allows any substances "substantially similar" in chemical structure to a Schedule I or II controlled substance, and which have an activity or is represented to have an activity similar to a Schedule I or II substance, to be charged as such. Because of the huge influx of these substances as drugs of abuse, and the serious concern they have caused nationally, prosecuting attorneys have begun to prosecute these cases using The Federal Analogue Act.
This presentation will follow one large synthetics importation and distribution case through the seizure, analyses, and trial phases, and will include many of the chemical issues encountered.
ADVERSE EFFECTS OF BLANKET QUALITY ASSURANCE CRITERIA ON THE INTERPRETATION OF SAMPLE-TO-SAMPLE AND LAB-TO-LAB VARIABLE DNA DATA
It is generally accepted that the data generated from an experiment speaks for itself and that while there may be disagreement as to the interpretation of a particular result, the disagreement can be articulated and each argument will be given the weight it commands. Because of the virtually universal adoption of PCR-based DNA analysis of "forensic unknowns," together with the sensitivity and personal discrimination provided by this universal technology the FBI QA Standards, CODIS Operating Procedures, and Scientific Working Group Guidelines define and prescribe various criteria that attempt to assure the quality of experimental data generated by accredited and CODIS-participating laboratories. However, the interpretation of that data will vary from sample to sample and from lab to lab, even with the same sample. That inherent and unavoidable variation allows for QA criteria intended to strengthen our reliance on the data to be applied in ways that undermine or mischaracterize the sample data or even ignore the sample data. Some case-specific examples including pre-trial and post-conviction evidence admissibility, mixture-interpretation avoidance, and CODIS eligibility as the result of the misuse of QA criteria will be presented.
I-502 AND THE WASHINGTON STATE PATROL CRIME LABORATORIES
Catherine Dunn and Jason Dunn
Washington state voters chose to change the law in 2012 by supporting Initiative 502 and making recreational marijuana use legal for adults. This vote generated several changes including a legal redefinition of marijuana, the Washington State Patrol (WSP) Crime Laboratories' approach to marijuana analysis, and regulation of marijuana sales. The WSP Crime Laboratories reviewed available literature, designed an analytical protocol for quantitative analysis of delta-9-tetrahydrocannabinol, and worked through the legislative process to alter a major flaw in the wording of the initiative. As the law was altered in 2014, the WSP Crime Laboratories continue to adapt procedures to meet the demands of the law regarding marijuana analysis.
RIP ROARING RAPIDS: EVALUATION AND COMPARISON OF THE INTEGEN X RAPIDHIT 200 VS. TRADITIONAL DNA TECHNIQUES FOR CRIME SCENE SAMPLES
Alice Neumann Hilker, Lilia Patino, and Tan Ho
Based on an actual crime scene scenario, we compared and evaluated the RapidHIT DNA instrument's performance versus traditional DNA lab techniques in the areas of time spent and concordance of data. Is it realistic to expect that crime scene personnel can load questioned samples into the RapidHIT at the scene and generate results during the course of an active scene and review the data upon arrival at the laboratory? Can mixed source samples that require differential extraction be loaded into the RapidHit instrument after an evaluation for sperm content and after the first part of the differential is performed?
In a brief evaluation period of two days, the San Mateo County Sheriff's Office was provided with one kit (28 sample cartridges) for evidence runs and one cartridge of 7 samples to run as a QC and reference run. Drawn blood and other forensic samples were used to re-create an actual crime scene. Duplicate swabs were collected allowing one analyst to run the questioned samples using the RapidHIT in "real time" while a second analyst used the laboratory's validated protocol to run the second swabs in "real lab time" at the laboratory. We compared the speed of analysis as well as the quality of the results obtained.
INTRODUCTION TO ADOBE LIGHTROOM
A brief explanation and demonstration of the uses and versatility of this software from the perspective of a criminalist who routinely uses it to assist with his crime scene reponse reports.
L.A. COUNTY SHERIFF'S OLDEST COLD HITS
Susannah Knetchel and Amber Sage
The Los Angeles County Sheriff's Department Scientific Services Bureau has been uploading forensic unknown profiles to CODIS since 1994. In that time, we have entered 8,152 profiles. Since our first hit in 1987, we have had 3,864 Cold Hits, or matches, to convicted offenders, and 1,164 case to case hits. A review was undertaken of the oldest Cold Hit cases worked by our laboratory. The criteria for the case review was one, it had a profile uploaded to CODIS, two, it hit on a convicted offender, and three, it was otherwise unsolved until the hit. Ten of the oldest cases that were reviewed will be presented. These cases were sexual assaults and homicides, and span 1972 up to the early 1980s. The focus of the presentation will be the individual case circumstances as well as the unique obstacles that older evidence can present when DNA analysis is necessary. The initial laboratory work will be contrasted against the different techniques and technologies that were used in the CODIS era to obtain a profile suitable for upload. When possible, the outcome of the cases will be presented as well as any additional work that was done on the case after the Cold Hit.
CAC AWARDS OVERVIEW
A brief introduction to the various awards and honors that are available to members of the CAC. Each year, the CAC recognizes its newer members, journeyman-level members, and "seasoned" members with a variety of awards, some that include significant financial benefit. However, there are relatively few members that either apply or are nominated to receive these awards. This talk hopes to inform members that these awards exist, what their benefits are, and encourage members to apply for them.
Greg Laskowski will provide a brief overview of the NIST Scholarship program.
HISTORY AND DEVELOPMENT OF THE CAC ETHICS ENFORCEMENT PROCEDURE
In October 1977 the CAC BOD adopted a revised policy on ethics enforcement entitled "Handling of Charges of Unethical Conduct; Procedures Regarding the Ethics Committee" in order to provide "firm guidelines". These procedures were to provide: 1) for the "full and knowledgeable participation of the membership in the proceedings" and 2) that "the burden of proof that a charge of ethical violation is founded rests solely with the Ethics Committee". Some other association business also occurred in October 1977. An ethics matter surfaced which proved to be the catalyst for an in-depth critical analysis of the propriety of the newly adopted ethics enforcement procedure. As a result of this critical analysis, the newly adopted ethics enforcement procedure was modified to handle the October 1977 ethics matter. In June 1979, a three person ad hoc committee was formed to draft a revised policy for enforcing the CAC Ethics Code. The final draft of this policy (the 5th one) was adopted by the CAC Membership on November 7, 1980 at the fall CAC Seminar in Yosemite Valley.
MEETING THE AB 1517 GOALS: THE OPD LAB STREAMLINED PROCESSES
Jennifer Mihalovich and Helena Wong
AB 1517 encourages "evidence of sexual assault ", which includes sexual assault evidence collection kits, to be submitted to the laboratory within 20 days of an incident OR for specimens collected at the hospital to be sent directly from the hospital to the crime lab within five days of the incident. The Bill encourages profiles from such evidence to be uploaded to CODIS within 120 days.
Alameda County has been in the untested sexual assault evidence collection kits (SA kit) spotlight for the last several years. The number of untested kits reported in the news ranged from 644 to over 2000 just for Oakland. The Oakland Police Department Criminalistics Laboratory has been analyzing SA kits under various programs for years. On December 31, 2013, the Department determined that approximately 220 victim SA kits had yet to be analyzed. Two different case management approaches were utilized to eliminate this backlog. One approach was to assign four scientists to work 80 kits in six weeks and the second was "All Hands on Deck". The backlog elimination date was set - August 31, 2014; all eligible DNA profiles have been submitted to CODIS as of August 22, 2014.
A RADS program was implemented within Alameda County on May 1, 2014 in which one to three samples were submitted by the hospitals directly to a lab. Since the OPD lab had streamlined SA kit processing, the Department elected to analyze contemporary SA kits within 20 business days. The OPD Laboratory approach was to analyze all potentially probative swabs and underpants. The PODS, teams of Forensic Biology scientists, acquired the kits from Property and Evidence Unit on Monday or Tuesday of the week with a CODIS eligible DNA profile entered into LDIS within ten business days of the receipt of the kit. The laboratory has met this goal and continues to meet the submission deadline of CODIS eligible profiles within the 120 days as recommended by the Bill.
BURN BARREL BABY
Heather Campbell and Kerry Russell
On August 18, 2012 a mother "freaked out". She admitted something bad had happened to her daughter and that she had made it worse. This presentation will cover the crime scene of a 2-year-old child burned in a burn barrel.
SYNTHETIC CANNABINOIDS INVESTIGATION/COURT PROCEEDINGS
Joseph E. Andreoli
This presentation will cover an investigation into the manufacturing and illegal sales of synthetic cannabinoids occurring in Boise, Idaho in 2011. The presentation will take a detailed look into the investigation leading up to search warrants, the execution of those search warrants, dismantling of the manufacturing operation and arrests, as well as the court battles that were fought regarding the investigation as well as the legality of the synthetic cannabinoids being used in the manufacturing process.
EFFECTS OF DIFFERENT SWABBING SOLUTIONS ON DNA RECOVERY
Nicole Grosey, Edward Panacek, MD, William Green, MD, and Cassandra Calloway
Recovering high yields of DNA from low copy number samples and samples with small amounts of DNA are important in forensic investigations. Swabbing methods and swab material have both been analyzed to improve DNA recovery, however, swabbing solution has not been thoroughly studied. Sterile water, currently, stands as the swabbing solution used for collecting potential DNA from surfaces, although, it has never been determined if it is better than other solutions. Detergents are known for their solubilization characteristics and may recover more DNA. Sterile water and five detergents (Triton-X 100, SDS, Tween 20, Formula 409, and Simple Green) were compared in their ability to recover DNA from a known saliva stain deposited on a glass slide, plastic cup, and glass bottle using quantitative PCR. Two different concentrations (2 and 3%) of SDS and Triton-X 100 were studied as well.
No differences were found between the eight different swabbing solutions. The five different detergents were not any more successful than water at recovering DNA from saliva deposited on a glass slide, plastic cup, and glass bottle. Even with a sample increase for water, SDS 3%, and Triton X-100 3%, the DNA yields were still similar to each other.
High variability was seen within solutions and between substrates with high standard deviations. Statistical significance was not present between solutions. Therefore, water should continue to be used as the swabbing solution for collection of saliva. In addition, on average, DNA recovery from the glass bottle and the plastic cup was less than DNA recovery from the glass slide. The glass bottle and plastic cup were technically more difficult to swab due to the curved shape of the substrates, which resulted in the lower DNA recovery.
THE EFFECT OF CYANOACRYLATE FUMING ON THE BLUESTAR REACTION
Trevor Allen and Rebecca Nelson
Cyanoacrylate (CA) fuming is sometimes performed while processing the interior of vehicles to preserve latent prints. Occasionally reagents such as Bluestar Forensic are also employed to detect latent bloodstains inside these vehicles. A white polymer coating is applied to surfaces within a vehicle upon CA fuming, which gave rise to the question if it interfered with the Bluestar reaction. An experiment was devised to determine if the Bluestar reaction would be inhibited by CA fuming on several different substrates commonly found in vehicles. Different blood dilutions were applied to these substrates and the Bluestar reagent was applied to sample sets before and after CA fuming. These results were photographed under the same settings and light conditions. Adobe Photoshop and Adobe Lightroom were used to evaluate the RGB color values associated with these reactions to determine if the color of the reaction was altered due to CA fuming.
THE GOOD NEWS/BAD NEWS CAPER: A COLD CASE COLLABORATION CROSSING STATE LINES IN SEARCH OF A SERIAL KILLER
Alice Neumann Hilker and Brittany Baguley
This presentation will discuss the investigation of the homicides of six young women in Northern California and Nevada in the early months of 1976. Our investigation spans nearly forty years and ten law enforcement agencies. It involves forensic evidence, profiling, re-testing, canvassing, and novel approaches to investigating cold cases.
ARE MONOZYGOTIC TWINS DISTINGUISHABLE BY HAIR PROTEIN PROFILES
Pei-Wen Wu, Robert H. Rice
Hair evidence can be an important element in criminal investigations because it is commonly recovered at crime scenes and is easily transferred between individuals and inanimate objects. Microscopic comparison and DNA analysis of hair shafts both provide useful information for identification of suspects. However, since nuclear DNA is generally lacking from hair shafts, the information gained is of limited discrimination ability. This project applies protein profiling to augment the value of human hair evidence based on findings that inbred mouse strains are distinguishable by profiles of their hair shaft proteins. Recent work has also shown that individual humans are distinguishable by their hair protein profiles, but whether identical (monozygotic or MZ) twins can be distinguished is uncertain. MZ twins are genetically identical, but significant phenotypic discordance can exist. Such differences may be attributable to epigenetic effects from developmental or environmental influences that alter gene expression. Therefore, this project explores the relative contributions of an individual's genetic constitution and development/environment to protein expression. Our study was conducted in a MZ twin cohort of 8 adult pairs through the cooperation of the California Twins Research Registry, and questionnaires regarding subject lifestyle and diet were also obtained. We collected samples of scalp hair for protein extraction followed by shotgun mass spectrometry analysis and spectral matching to the human protein database. Since certain peptides can overlap among the keratins, data were analyzed as either weighted-normalized or exclusive spectral counts to avoid this problem. Using either approach, twin pairs were readily distinguishable from each other by their protein profiles, consistent with previous findings comparing unrelated individuals. By contrast, distinguishing between the two twins of an MZ pair was difficult. Using exclusive spectral counts, the most discriminating option, profiles of several proteins distinguished between individuals in a single twin pair, and the twins in only one pair were distinguished by profiles of as many as three proteins. These results mimicked those with siblings of inbred mice, analogous to human MZ twins. Unlike dermatoglyphs, which are generated by developmental processes, hair protein profiles appear to be under strong genetic control and thus are much less discriminating among MZ twins than fingerprints. A role for epigenetic effects of ageing cannot be ruled out but, if it occurs, it appears to be uniform within twin pairs. Epigenetic effects of development and other environmental influences appeared small in this cohort. Thus, our preliminary data support the possibility of establishing a protein database for distinguishing among individuals (except MZ siblings). In conducting this study, an improvement in methodology was introduced. Instead of using sodium dodecyl sulfate to disrupt the hair structure and permit efficient disulfide reduction and alkylation, sodium dodecanoate was employed. This related detergent was removable by extraction with organic solvent after acidification, avoiding the ethanol precipitation step in our original protocol for detergent removal. This innovation is anticipated to permit processing of much smaller hair samples than were previously practical.
QUANTITATIVE ALGORITHM FOR DIGITAL COMPARISON OF TORN AND CUT DUCT TAPE
Alicia Alfter, Fred Tulleners M.A., and William Ristenpart Ph.D.
The NRC established a need at the national level for the validation of forensic science methods. Currently, duct tape end matching is based on human judgment with no quantitative criteria for identification. In this research, the needs of the forensic science community are met by minimizing human contextual bias via a quantitative imaging algorithm, and corresponding mathematical methods to extract the edge profiles of torn and cut duct tape samples. The detected edges of the exemplar and an arbitrarily large number of test samples are algorithmically subtracted from one another. The resulting residuals are then used to calculate the sum of squared errors (SSE), a succinct metric that allows quantitative comparison of possible matches. A best or "most likely" match is determined by identification of the match with minimal SSE. The digital results are compared to a prior study of the same set of duct tapes that were visually assessed by a group of three researchers as part of an error determination study, thus providing a quantitative estimate of the respective error rates.
The MATLAB® software platform is used to code a series of mathematical functions in order to extract useful information from an image or a series of measurements. This research uses MATLAB® to obtain an edge profile of the duct tape image and performs analysis on the data. A digital image of the duct tape is collected using a high-resolution scanner at 1,200 DPI. A digital profile of the tape is developed using the tear region and the parallel edges of the duct tape. The software performs a series of automated tasks which include the software setting threshold levels, performing an ad hoc smoothing mechanism to remove the yarns, and converting the coordinate points into a graphical format to assess the degree of difference along the tear region. The results are displayed on a color map graph showing the difference of the SSE values for a matching piece of duct tape in comparison to the other duct tape pieces in the database. The user examines the residual calculations and determines whether one pair is quantitatively a better match than other pairs examined. The results establish that if other pairs of known matches have SSE values in the same range, it strongly suggests that it is the correct match. Using our quantitative mathematical algorithm, we will discuss the capability of the algorithm to identify matching specimens in set of 200 duct tapes of a particular brand, look at overall residue values by themselves as an indication of uniqueness, and quantify the number of false positives and false negatives. This study will compare and contrast our results with the findings of prior researchers who conducted a manual comparison of these same duct tape specimens. This prior study was published in JFS 2012 by McCabe et. al. The end product is a quantitative and statistically rigorous guideline for end match comparison.
VALIDATION OF AUTOMATED PREPFILER VERSUS ORGANIC MANUAL EXTRACTION
Luis Sandoval, Steven Lee, Brooke Barloewen
The isolation of DNA from forensic samples is the most imperative, yet challenging, step in DNA profiling. Biological samples at crime scenes can be found in a variety of conditions which can expose the DNA to inhibitors and nucleases; all which impede STR Profiling. We investigated the efficiency of manual DNA Organic Extraction as compared to that of the new PrepFiler kit, which uses magnetic particles to bind and elute DNA, and is coupled with an automated robotic system. We also introduced the use of the Lysep Column which simplified the separation of a substrate from the lysate, thus minimizing human manipulation of a sample. We hypothesized the PrepFiler Extraction kit will improve the quantity and quality of DNA isolation in comparison to Organic Extraction. Blood and saliva samples in a variety of concentrations were extracted and evaluated in a substrate study to address sensitivity, reproducibility, and accuracy. The performance of both extractions were assayed using qPCR to compare quantities of DNA isolated, and STR amplification to detect any inhibitor or nuclease contamination. Results showed traditional manual techniques had greater recovery and sensitivity compared to PrepFiler at higher concentrations, but at lower concentrations the PrepFiler kit outperformed by yielding higher quantity and quality of DNA. Future work includes testing PrepFiler efficacy on other biological samples, and samples with nucleases and inhibitors. Overall future laboratory workflow would benefit from using the robotic system coupled with the PrepFiler kit, especially in cases with limited DNA samples, and would allow for higher throughput, reduction of PCR inhibitors, and eliminate use of toxic Phenol:Chloroform:Isoamyl Alcohol.
DEVELOPMENT AND PRESERVATION OF ENVIRONMENTALLY INSULTED FINGERPRINTS THROUGH THE USE OF COLUMNAR THIN FILMS
Zachary C. Goecker, B.S., Stephen E. Swiontek, M.S., Akhlesh Lakhtakia, Ph.D., D.Sc., and Reena Roy, Ph.D.
Traditional fingerprint-development techniques do not generally protect the latent residue. This is especially disadvantageous in cases where genetic material in the residue may be useful for identification. Fingerprints that have been exposed to environmental insults such as ultraviolet radiation, extreme temperatures, humidity, and time could yield degraded and low amounts of DNA. That in turn may generate incomplete DNA profiles. By analyzing genetic degradation through quantitative Polymerase Chain Reaction (qPCR) of the DNA recovered from fingerprints, development techniques can be compared in regards to their ability to protect the molecular integrity of genetic material.
The fingerprint-development techniques that are used in this research are cyanoacrylate fuming, black-powder dusting, and columnar-thin-film (CTF) deposition. The CTF technique involves the resistive heating of a material inside a low-pressure chamber. That material evaporates and condenses conformally as a tight stack of upright nanoscale columns atop a fingerprint. The CTF entombs the entirety of the residue, serving as a barrier between the residue and the environment, and potentially preserving DNA in the residue.
Latent fingerprints were harvested from multiple donors and placed on one-square-inch brass substrates. These samples were subjected to two types of environmental insults (quantified by temperature and humidity) for certain durations. An equal number of samples were then developed by the CTF, cyanoacrylate fuming, or black-powder-dusting techniques. The quality of each of those developed fingerprints was determined subjectively using a comparative-quality method employed previously in this laboratory. The quality was also assessed using an objective-quantitative assay formulated through the use of Universal Latent Workstation (ULW) and other software.
Biological material from the developed fingerprints was collected using a wet swab and subjected to low-template DNA-analysis methods involving centrifugal separation of cellular components, previously used in this laboratory. DNA was then quantified using the newly developed Trio kit from Applied Biosystems® and the InnoQuant™ kit from InnoGenomics. The yield of DNA from fingerprints, which had been aged for defined periods of time, allowed the researchers to compare the degree of degradation due to the chosen development techniques. The collected data was also beneficial to explore the relationships between the development techniques, environmental insults, and the degree of DNA degradation.
The results from this research indicate there is a sufficient quantity of DNA in multiple latent fingerprints to analyze DNA amplicon length ratios. Thus, it is possible to determine the amount of degradation in the sample. Also, DNA was successfully extracted from beneath the CTF, pointing to the potential of the CTF development technique in the biological sector of criminalistics. Current data shows that the post-development quality of fingerprints previously exposed to -10°C decreases as the duration of exposure increases, although development itself can either improve or worsen the quality, depending on the parameters used for the development technique.