83rd SEMI-ANNUAL SEMINAR (Spring 1994)
CALIFORNIA ASSOCIATION OF CRIMINALISTS
BEING AN EXPERT DOESN'T MAKE AN EXPERT WITNESS
Richard Koniecska, Sound Communication, 3633 Beach Drive Soutbwest, Suite 402, Seattle, Washington, 98116
The purpose of the presentation is to sensitize the audience to the difficulties involved in reaching a jury with technical information. The emphasis will be placed on making the information simple and easily understood and presenting the information in a conversational manner that will help build credibility and trust with the jury. Examples of techno-rhetoric that distances the witness from the jury will be provided as well as ways of simplifying the language. The attendees will walk away with a heightened appreciation of the jury's dilemma of ruling on a case with only limited information and that burden can be eased with simpler testimony.
STRATEGIES AND CONSIDERATIONS FOR CHOOSING THE MOST APPROPRIATE DNA TYPING TESTS FOR A VARIETY OF SAMPLES
Rebecca Reynolds, Human Genetics Department, Roche Molecular Systems, Inc., 1145 Atlantic Ave, Alameda, CA
The availability of several validated RFLP and PCR-based DNA typing assays creates the need for the criminalist to make a choice about which test is most likely to yield the most discriminating information for a particular sample. The characteristics of a sample that can influence this choice include quantity and quality of extracted DNA, likelihood of a mixture, source, and age. For example, a large, week-old bloodstain is likely to yield unambiguous results using the RFLP method. Since this method is the most discriminating of all available single tests, a criminalist should perform RFLP typing if the sample is likely to be probative (provided the laboratory has the capability and no time constraints). For more limited samples and mixtures, the choice of test is less obvious and more critical, particularly if only one or two assays can be performed. The importance of the ability of several PCR-based typing tests to amplify degraded DNA and to detect and distinguish mixtures will be related to and weighed against the ease of results interpretation and power of discrimination for each system.
TRACKING DOWN DNA CONTAMINATION IN REAGENTS
Marc Scott Taylor and Ann Challed, Technical Associates, Inc., 952 Athens St., Altadena, CA 91001
The discovery of DNA in reagent blanks can be one of the most disruptive occurrences in the functioning of a DNA testing laboratory. An incidence of non-human DNA as a contaminant in a reagent purchased from a supplier will be described. The procedures for reagent and solution tracking utilized in this laboratory that allowed for the rapid isolation and identification of the source of the contaminating DNA will be discussed. The incidental discovery of nonspecific amplification of 300+ bp product from this nonhuman DNA when utilizing the Amplitype PM (Polymarker) reagent set will also be shown.
QUANTIBLOT: RAPID, ACCURATE AND SENSITIVE QUANTITATION OF HUMAN DNA
Sean Walsh, May Alaveren, Joseph Varlaro, Rebecca Reynolds, Human Genetics Department, Rocbe Molecular Systems, Inc., 1145 Atlantic Ave., Alameda, CA
The QuantiBlot Human DNA Quantitation Kit provides a sensitive and simple method for the quantitation of human DNA. This method is based on probe hybridization to a human alpha satellite locus, D17Z1. Sample DNA is immobilized onto a nylon membrane, and then hybridized with the biotinylated QuantiBlot probe. The subsequent binding of streptavidin-horseradish peroxidase to the bound probe allows for either colorimetric (TMB) or chemiluminescent (ECL) detection. For either detection method, the entire procedure can be performed in less than two hours, which is significantly faster than the 8 or more hours required for alkaline phosphatase-based detection systems, and can detect DNA quantities down to 150 pg. Much lower quantities of DNA can be quantitated when using chemiluminescent detection by performing longer film exposures. The chemiluminescent method also allows for very convenient multiple film exposures. Several development and validation studies will be presented demonstrating the specificity and accuracy of the QuantiBlot Kit method for forensic samples. QuantiBlot is particularly useful for quantitation of Chelex extracted DNA samples and other non-purified DNA samples that cannot be accurately quantitated by other methods. The importance of DNA quantitation in achieving optimal results for different DNA based typing systems will be discussed.
DEVELOPMENT OF THE AMELOGENIN LOCUS FOR FORENSIC GENDER IDENTIFICATION
Caroline Garcia and Norah Rudin, Department of Justice DNA Laboratory, Berkeley, CA 94710
Gender identification is one of the first major steps in the analysis of forensic biological evidence. The human amelogenin gene on the X-chromosome and the amelogenin-like gene on the Y chromosome have been cloned, sequenced and utilized in a PCR based gender identification system (Nakahori et al, 1991). X and Y sequences are co-amplified and yield fragments of different lengths: X-specific 977 bp and a Y-specific 788 bp fragments. 250ng of DNA was required (Akane et al, 1991). The goals of this study were to:
- Improve the sensitivity of the Amelogenin locus PCR based gender ID system;
- design a new primer to improve the resolution between X and Y products and;
- test for compatibility with other genetic marker systems for simultaneous analysis.
DNA was extracted from bloodstains using an organic extraction. A new Amelogenin primer was designed which produces smaller products: X-specific 540 bp and Y-specific 356 bp fragments. These primers were tested under different conditions in order to improve the sensitivity and resolution of this system. The new primer sequence provides several advantages:
- The sensitivity of both the original and new system was increased down to 0.5ng using new amplification conditions;
- The resolution was increased due to better separation of smaller X and Y PCR products. Furthermore, the smaller products will more reliably amplify from degraded DNA template and;
- Preliminary studies have shown that fragments produced with the new primers show compatibility with some STR systems for simultaneous analysis on a single gel matrix (Lee et al. 1994, this meeting).
CO-AMPLIFICATION OF THE AMELOGENIN GENE WITH DQ-ALPHA UTILIZING THE AMPLITYPE REACTION MIX AND AMPLIFICATION PROTOCOL
Marc Scott Taylor and Ann Challed, Technical Associates, Inc., 952 Athens St., Altadena, CA 91001; Elizabeth A. Jobnson, Ph.D., Harris County Forensic Center, 1885 Old Spanish Trail, Houston, TX 77054
Co-amplification of genetic loci is of extreme interest to the Forensic Scientist because many evidence samples have very limited quantities of DNA. A multiplex system utilizing primers for the amelogenin gene added to the standard AmpliType HLA DQ-alpha reaction mix and utilizing the standard DQ-alpha thermal cycling parameters has been explored based on the work of Mannucci, et al (AAFS 1994 Poster). This system allows determination of the gender of the source individual in addition to the DQ-alpha type. Problems encountered with this system, modifications to balance the amplification of the target genes and utilization of a high resolution gel system for detection of the amelogenin PCR product will be discussed.
DNA SEQUENCE ANALYSIS OF D1S80 COMMON AND VARIANT ALLELES
Rebecca Reynolds, Gregg McClure, Joseph Varlaro, Susan Flood, Human Genetics Department, Roche Molecular Systems, Inc., 1145 Atlantic Ave., Alameda, CA
The Ampli FLP D1S80 Allelic Ladder contains 27 D1S80 alleles. The ladder alleles are the most common form of each allele, based on frequencies in the FBI D1S80 database. D1S80 allele variants exist and are detected by their mobility shift relative to the corresponding allele in the ladder. We have sequenced ladder alleles 14,16,17, 18, 21 and 24. This information allowed allele designations to be made based on the number of repeat units. In addition, the 18 allele from a total of 8 individuals from three population groups was sequenced and all of the allele 18 sequences are identical. A variant of allele 17 and of allele 21 has also been sequenced. The two most striking observations from comparison of all of the sequences described above are that at least 15 distinct l6 bp repeat unit sequences exist and, aside from two conserved blocks of sequences, the arrangement of the remaining repeat units between alleles appears to be random, even between the common and variant forms of alleles 17 and 21. This study suggests that the mobility difference between common and variant alleles is most likely due to sequence variation rather than length variation.
THE APPLICATION AND EVALUATION OF D1S80 FOR CASEWORK ANALYSIS
Renee Montgomery(1), Richard Showalter(2), Steve Myers(1), Gary Sims(1), Donna Dowden(1), and Keith Inman(3)
(1) California Department of Justice, DNA Laboratory, Berkeley CA
(2) Agouron Pharmaceutical Inc., La Jolla CA
(3) Oakland Police Department, Oakland CA
The Polymerase Chain Reaction (PCR) can be used to amplify units of repetitive sequences known as Variable Number of Tandem Repeats (VNTRs) which contain fragment length polymorphisms. By using gel electrophoresis on amplified fragment length polymorphisms (such as D1S80), a discrete band pattern can be achieved. In our laboratory we have validated a D1S80 typing system based on the PE/RMS AmpliFLP D1S80 PCR Amplification Kit and a modified version of the vertical gel system by Sajantila and Lukka (Intt J Leg Med 1993: 105:355-359). This marker proves to be helpful with interpretation of small amounts of mixed samples, such as sexual assault evidence that can often be difficult to interpret with DQA1 results alone. D1S80 in conjunction with DQA1 can provide sufficient information to discriminate between individuals. We will be presenting some of our early casework experience in which D1S80 was able to clarify the interpretation of results obtained by DQA1 typing.
ARTIFACTS IN D1S80 TYPING: EXPLANATIONS AND SOLUTIONS
Mary Hong and Eva Steinberger, Orange County Sheriff-Coroner, 320 N. Flower Street, Santa Ana, CA 92703
The quality of D1S80 data is usually excellent. Occasionally, however, artifacts interfering with the interpretation of the analysis are observed. The most troublesome artifacts are the appearances of unexpected bands in a D1S80 profile. We determined that "extra" bands, weak or strong, usually with an electrophoretic mobility different from common D1S80 alleles, are most likely due to heteroduplex formation among the PCR products. Weak bands, smaller than the main PCR products, but in line with common ladder alleles, can be explained through PCR product reannealing in the PCR plateau phase. We show that both artifacts are caused by excessive initial PCR template concentration. Sample overloading in composite gel electrophoresis was found to be the cause for "buddy" bands, probably due to a correspondingly high amount of breakdown DNA products in the sample. As described in the literature, allelic dropout was observed at suboptimal MgCl2 concentrations in the reaction mix. Several reasons for unsatisfactory DNA band quality as a consequence of electrophoretic or silver staining artifacts will be discussed.
STRS ALLELIC STRUCTURE AND APPLICABILITY TO FORENSIC CASEWORK
S. Rand, B. Brinkmann, Institute of Legal Medicine, Von-Esmarch-Str. 86, D-48149, Munster, Germany
The most effective way to identify the alleles in STR (short tandem repeat) systems is by comparison with a defined allelic ladder. This is achieved by sequencing all the alleles in simple systems such as HumTH01 and selected alleles in more complicated systems such as HumACTBP2 (SE33). The nomenclature for simple systems such as HumTH01 is straight forward but for systems such as SE33, where the repeat structure and sequences are variable, the nomenclature becomes more complicated. In stain cases, however, this presents no problems when a direct side-by-side comparison with the allelic ladder is carried out. Although sequence differences between alleles of the same length can lead to different mobilities in different gel systems, identification is non-problematic as long as the same gel system is used.
USE OF SHORT TANDEM REPEAT MARKERS FOR FINE MAPPING OF A GENE
L.M. Calandro and G.F. Sensabaugh, U.C. Berkeley School of Public Health, Berkeley, CA 94720
Short tandem repeat (STR) markers have become increasingly useful in the mapping of hereditary human diseases. Typing of an ordered set of STR markers has provided linkage information for a number of genetic diseases. We have utilized 3 STRs on chromosome 6 to fine map the location of the hereditary hemochromatosis (HHC) gene. HHC is an autosomal recessive disorder of iron metabolism. The gene has been previously localized to the short arm of chromosome 6 due to an association of the HLA-A3. We have been able to further delineate the gene region by typing affected individuals and their families at STR loci around HLA-A. In our study mapping has been facilitated by detection of a recombinant individual. Whole blood from HHC family members was collected and each individual was HLA typed by serology. DNA was extracted from buffy coats using a non-organic extraction method. The STR markers D6S105, D6S89 and F13A1 were typed by PCR with one primer end-labeled. Typing of the proband of one family revealed a recombination between HLA-A and D6S105 with its origin in the proband's mother. The proband appears to have acquired HHC as a result of this recombination. Typing this family for 5 chromosome 6 markers has enabled us to localized the candidate gene region to telomeric to HLA-A.
MICROWAVE EXTRACTION AND FIVE-MINUTE QUANTITATION OF DNA FROM BLOOD FOR PCR: AMPLIFICATION OF SHORT TANDEM REPEATS
S. B. Lee, M. Ma, K:P. Inman, B. McNamee, J, Bashinski, *J. W. Schumm, "C. Sprecher and *A. Lins, Department of Justice DNA Laboratory, Berkeley, CA 94710; Promega Corporation, 2800 Woods Hollow Road, Madison WI 55711
The objectives of this study were to:
- Evaluate the utility of a microwave mini-prep technique (.Goodwin and Lee. 1993 Biotechniques 15:438) for extraction of DNA from liquid and dried blood,
- develop a rapid, accurate, DNA dot quantitation method and
- amplify STRs from the microwave extracted DNA.
Blood samples in lysis buffer were incubated at 4°C for 1 hr, then microwaved for 1 min. After one organic extraction, DNA was precipitated in isopropanol and resuspended in TE. 1 μl each of standard DNA and unknown DNA was spotted onto agarose/EtBr poured onto a glass slide. DNA visualized under UV was quantitated by comparison to standards. The DNA was transferred by alkaline capillary blotting (30 minutes) and quantitated using a chemiluminescent probe (ACES kit). Th01, CSF1PO and TPOX were amplified from 10-15 ng of DNA, separated by acrylamide gel electrophoresis and detected by silver staining using Promega protocols. Microwave extraction yielded from 40-650 ng per 50μl of blood (averaging 210 ng). The 5 minute dot quantitation method yielded results that were comparable to previously validated methods (2-4 hours) as determined by computer densitometry of standards. Amplification of STRs using 10-15 ng from every tested sample demonstrated the utility of microwave DNA extraction from blood for PCR.
VALIDATION OF THE AMPLITYPE EM PCR AMPLIFICATION AND TYPING KIT
Nicola Fildes, B.S., B. May Alavaren, and Rebecca Reynolds, PhD., Roche Molecular Systems, Inc., 1145 Atlantic Ave., Alameda, CA 94501
The AmpliType PM PCR Amplification and Typing Kit has been developed for the DNA typing of biological tissues and fluids by forensic scientists. The AmpliType PM system uses the polymerase chain reaction (PCR) to coamplify six genetic loci, including DQAl, which are subsequently detected using immobilized sequence specific oligonucleotide probes. The five PM loci are detected on a single DNA probe strip and the DQA1 locus is typed on a separate DNA probe strip. The power of discrimination of the AmpliType PM system, including DQA1, ranges from 0.9994 to 0.9999, depending upon the population. Roche Molecular Systems validates it human identity products in accordance with the Technical Working Group of DNA Analysis Methods (TWGDAM) guidelines. The results of the validation studies will be presented, including analysis of mixed samples, liquid versus stain samples and non-human DNA. The effect of degradation on the AmpliType PM system will be discussed and compared to results obtained when each locus is amplified individually with degraded DNA. The results of two AmpliType Field Trials that demonstrate the consistency and reproducibility of the AmpliType PM Kit will also be reviewed.
FORENSIC APPLICATIONS OF FT-IR MICROSCOPY
William T. Wihlborg and John A. Reffner, Spectra-Tech Inc., 2 Research Drive, PO Box 869, Shelton, CT 06484-0869
FT-IR microscopy is a widely accepted tool for trace evidence evaluation. Spectroscopic characterization of fibers, paint, documents, explosive devices or any other condensed phase material of forensic importance are quickly and non-destructively analyzed. Specific casework and research results are presented to illustrate the usefulness of FT-IR microscopy in characterizing evidence.
THE CURRENT STATUS OF CALIFORNIA LEGAL ADMISSIBILITY STANDARDS
Rockne P. Hanmon, Senior Deputy District Attorney, Alameda County
Since 1976 California has adhered to a legal admissibility standard based on the California Supreme Court's interpretation of Frye v. United States. This rule is know as the Kelly-Fry rule. Subsequent decisions by the California Supreme Court clearly limited the scope and duration of Kelly-Frye admissibility hearings. Litigation arising out of the admissibility of forensic DNA typing has had a significant impact on the current interpretation of Kelly-Frye. A decision by the First District Court of Appeal, People v. Barney (1992), broadened the scope of Kelly-Frye admissibility hearings and created a new requirement that some level of admissibility hearing is always necessary. The California Supreme Court declined to review Barney or any of the other subsequent appellate decisions. There have been numerous appellate decisions since People v. Barney. Most have been non-published. None has resulted in the reversal of a conviction. None of these decisions engaged in the type of appellate review mandated in People v. Barney, nor attempted to assess the scientific landscape to evaluate developments since Barney was decided. The failure to continue. to make these evaluations is itself a violation of the method of appellate review prescribed in Barney. Instead, each of these decisions relies on Barney as having definitively decided the admissibility issue. In so doing, each has relied on the "snapshot" of Barney rather than the "moving picture" of science. In People v. Leahy dealing with the admissibility of "horizontal gaze nystagmus" field sobriety test for driving under the influence, the California Supreme Court has invited the parties to address whether Kelly-Frye should be maintained, or whether it should adopt the less austere admissibility test recently described by the United States Supreme Court in Daubert v. Merrell-Dow. Amicus curiae briefs have been filed by the California Attorney General, the California District Attorneys' Association and the Criminal Justice Legal Foundation making numerous recommendations.
A BITE MARK THROUGH CLOTHING?
Duane E. Spencer, D.D.S., Forensic Dental Consultant, 1855 San Miguel Dr. Suite 9, Walnut Creek, CA 94596
The bodies of two murdered women were found in a grassy field near Richmond CA. Bite marks were found on each body. Ants had also been active with the bodies prior to discovery. A suspect was apprehended and the odontologists compared his teeth with the bite marks. The bite mark comparisons will be explained as well as a discussion of the importance of obtaining saliva washings from suspected bite marks. Just prior to trial the defense suggested that one of the bites may have occurred through the victims panties. How was this important to the subsequent verdict? A guilty verdict was returned and a sentence of life without parole was issued.
SIMULATING BLOOD SPURTS WITH THE EFD AIR-POWERED DISPENSER, MODEL 2000XL-15
George Levine, California Department Of Justice-Santa Barbara, 820 Francis Botello Rd
Goleta, CA, 95117
To validate a theory about an unusual blood splatter pattern on a victim's leg, the EFT air powered dispenser, Model 2000XL-15, was used to duplicate the conditions of systolic blood pressure. The tube used had an inside diameter that approximated the artery diameter and a hole cut in the side of the tube approximated the partial severing of the artery. What makes the theory less plausible is the artery's location behind the victim's mouth. The theory has enormous implications in the case, disputing the defendant's claim that the wounds were self inflicted.
ARE WE SEEING THE SAME THING? RESULTS OF A SURVEY PRESENTED TO FORENSIC DOCUMENT EXAMINERS
Martha Blake, Forensic Document Examiner, San Francisco Police Department, 850 Bryant St., San Francisco, CA 94103
The methodology used by document examiners in handwriting comparisons is often criticized for lacking scientific foundation. In an attempt to validate handwriting comparisons, a pilot study was designed to see if document examiners are consistent in assigning evidential value to handwriting characteristics. In May of 1993, at the Southwestern Association of Forensic Document Examiners seminar, a document problem and a survey were distributed to attendees. Examiners were asked to compare a hand printed robbery note to hand printed request exemplars from a subject and determine if the note was written by the subject. The examiners were then asked to rank each letter type (and other hand printing characteristics) as low, moderate or high in significance (high meaning more individual quality of the observed letter form, etc. in this case only). The problem/ survey was also distributed to students with no experience in forensic document examination. The results of surveys completed by 33 Forensic Document Examiners and 36 students were compared and will be discussed.
CANINE ACCELERANT DETECTION TEAMS: VALIDATION AND CERTIFICATION
JD DeHaan, CA-DOJ-CCI, 4949 Broadway, Sacramento, CA 95820
Since 1986, canines have become more common in fire investigations. Today, both public and private agencies offer canine support, with some 18 teams operating in the western U.S. The dogs have demonstrated great sensitivity to gasoline and other common flammable liquid accelerants but questions have been raised regarding their specificity and reliability. Since a canine (or even its handler) cannot be cross-examined about its analytical approach, accuracy, reproducibility or limits of detection (like a criminalist can), it becomes necessary to independently validate the canine's "indications." This paper will report on a series of discrimination and detection limit tests. Samples of various burned substrates were prepared and spiked with small (0.3-10μl) quantities of various flammable liquids. The samples were presented to the canines as blind samples, and their reactions (indications) were videotaped. The samples were returned to the laboratory for verification. The paper will also report on a joint Fire Marshal/CCI project to certify canine teams based on their performance on a standardized test. This January 1994 test, included both "can" tests and a search of a burned room which had been spiked with 20-50 μl quantities of 6 accelerants. These test results will be described and discussed.
FROM ALCHEMY TO MASS SPECTROMETRY
JD DeHaan, CA-DOJ-CCI , 4949 Broadway, Sacramento, CA 95820
Very few criminalists practicing today remember what was required of them in fire investigation cases 40 years ago. In this paper, we get a glimpse of what laboratory science could (or couldn't) do in the days before gas chromatography or personal computers. Debris analysis was limited to steam distillation, followed by measurements of refractive index, flash point, and specific gravity. If there were less than 0.5 ml recovered, one could not be very specific in an identification. Chemical spot tests sufficed for most incendiary identifications. While emission spectrography was available, infrared and even UV spectrophotometry were almost unheard of. At the scene, detection was limited to what could be smelled and our understanding of the physics and chemistry was far from adequate. This look back should reassure us that we really have made great progress - with our access to gas chromatography/mass Spectrometry, computer-fire models, and even canine assistance!
PEOPLE VS. RANDY KRAFT: A SMALL CASE WHICH BECAME A NATIONAL EVENT
Robert R. Ogle, Jr., Forensics Consultant, 124 Valley Oak Lane, P.O. Box 5267
Vallejo, CA 94591
This paper points out the disastrous results which resulted from a failure to communicate amongst the investigators in the People vs. Kraft case, a serial murder case with thirty-seven alleged victims prior to trial. Had the cases of all thirty-seven alleged victims been presented, the Kraft case would have been the largest serial murder case tried in the United States up to that point in time (at trial, sixteen victims were alleged in the guilt phase, eight instead of twenty-one were alleged in aggravation). This paper describes the presence of compelling evidence in two cases in 1985, which, taken together, would have presented a strong case against the defendant at that time. However, the failure to share information between jurisdictions involved frustrated the arrest of the defendant at that time. At the time of the defendant's arrest some eight years later, the deaths of twenty-three of the victims to be presented at trial had occurred, all of which could have been prevented had the investigating agencies shared their information in 1985. The conclusion drawn from this case is that when multiple jurisdictions are involved in the investigation of serial homicide cases, it is imperative that all the agencies and investigators involved in the investigation cooperate in the sharing of information regarding potential suspects.
ANALYSIS OF OLEORESIN CAPSICUM REVISITED-WITH EMPHASIS ON "PEPPER SPRAY" DEVICES
John P. Bowden, California Department of Justice, California Criminalistics Institute
4949 Broadway, Sacramento, CA 95820
Recently the State of California approved the use of oleoresin capsicum ("pepper spray") hand-held tear gas devices, first for law enforcement use and subsequently for the general public. The author worked with due Dept. of Justice, Bureau of Criminal Identification and Information in developing standards for the tear gas devices. His studies included instrumental analyses of Capsicum pepper extracts and of commercial spray device contents. The presentation will cover the application of Gas Chromatography/ Mass Spectrometry (GC/MS) and Gas Chromatography/Fourier Transform Infrared Spectrophotometry (GC/FT-IR) in the analysis of these products. Methodology and identification of the numerous components present will be discussed.
METHCATHINONE - A POTENT NEW DRUG OF ABUSE
William L. Pickard, University of California at Berkeley
Methcathinone ("cat"), a novel amphetamine analogue, is being observed in emergency room admissions in the midwestern United States. As a strong euphoriant and stimulant with a short duration of action, methcathinone abuse is growing and represents a potentially severe public health problem. Reportedly the drug of choice in the Russian "speed" culture, this amphetamine analogue could potentially supplant methamphetamine due to its extremely facile synthesis and the ready availability of chemical precursors. Chemical syntheses are currently being discussed on electronic-mail networks. We will present information on the chemistry, pharmacology, and toxicology of methcathinone. Historical details of the pharmacoepidemiology will be presented, from its widespread abuse in Russia to the seizures of the first clandestine laboratories in the United States - items which led to methcathinone's recent classification as a Schedule I drug by the Drug Enforcement Administration. Subjective effects of methcathinone include increased alertness, euphoria, and increased libido. Heavy or repeated use may result in agitation and symptoms of psychosis. Clinicians should be cognizant of this new stimulant of abuse.
APPLICATION OF MULTILINEAR EVENTS SEQUENCING (MES) ANALYSIS TO THE RECONSTRUCTION OF A SHOOTING INCIDENT
Peter D. Barnett, Forensic Science Associates, 3053 Research Drive, Richmond CA 94806
Multilinear Events Sequencing (MES) is an analytical procedure for the organization, validation, and quality assurance of the investigation of a unique event. Originally developed for complex accident investigations, MES is applicable to the investigation of any unique event. MES is based on the concept that reconstruction of an event requires an understanding of the changes that occur in the system being studied. Each change is initiated by an "actor", and each change in turn initiates one or more other changes leading to the final state of the system. MES analysis combines investigative information, observations at the scene, and technical findings to define a sequence of events. Each event, a change produced by an actor at a particular time, represents a building block. These building blocks, when combined in a flow chart defined by actor and time, recon-struct the event being studied. In this presentation MES will be applied to the reconstruction of a shooting in which the position of the shooter was disputed. The changes in the gun, bullet, vehicle, shooter, victim, and blood are combined in a sequence of building blocks to define the reconstruction.
CURRENT STATUS AND ACTIVITIES OF ASTM COMMITTEE E30 ON FORENSIC SCIENCE
Peter D. Barnett, Forensic Science Associates, 3053 Research Drive, Richmond CA 94806
ASTM develops standards for materials, products, systems, and services. The various standards development activities are carried out by over 130 technical committees in areas as diverse as Steel and Emergency Medical Services. Committee E30 on Forensic Science has been in existence for over 15 years, but in the past 5 years has shown a resurgence of activity. E30 is composed of several subcommittees, including Criminalis-tics, Engineering, Questioned Documents, and Terminology. Committee E30 considers the development of standard procedures and practices to go along with the processes of individual certification by the American Board of Criminalistics, and laboratory accreditation by ASCLD-LAB, as part of a three part approach to quality assurance in criminalistics. The criminalistics subcommittee has produced over 10 standards in areas including analysis of fire debris, analysis of gun shot residue, and documentation and labeling of evidence. Current standards under development by the Criminalistics subcommittee deal with paint analysis, analysis of controlled drugs, and procedures for reconstruction of incidents. Membership in ASTM is available to anyone, but participation on the task groups that actually develop the standards is not restricted to ASTM members.
THE CAC CRIMINALISTICS E-MAIL FORUM
Ronald L. Moore, Orange County Sheriff-Coroner, 320 N. Flower St., Santa Ana, California, 92703
Electronic mail and other types of computer communication can provide an increased level of communication between forensic scientists, and make available more information and resources. This can be accomplished using existing computers with modems and existing network service providers. The CAC is starting an E-mail forum, an on-line study group on criminalistics. Subscribers will submit to a central E-mail address questions on techniques, bulletins, announcements, general questions, and comments, which will be emailed to all subscribers E-mail accounts. Subscribers read the submissions and may respond by sending their own message to the central address, which repeats the process. Thus ongoing discussions are possible. The advantages of E-mail and mailing lists as a communication media for forensic scientists will be discussed.
A COMPARISON OF BLOOD AND BREATH ALCOHOL LEVELS FROM ARRESTED DRIVERS
Ronald L. Moore, Orange County Sheriff-Coroner, 320 N. Flower St., Santa Ana, California, 92703
Blood and breath tests from drivers arrested in Orange County who voluntarily gave both samples were collected over a period of one year. Blood samples were analyzed by headspace gas-chromatography. Breath samples were analyzed by Intoxilyzer 5000. Both samples were analyzed in the normal course of operations of the crime lab. Comparison of these results shows a very good correlation between blood and breath results in the range of concentrations typical of traffic law enforcement. Several possibilities are offered for the majority of underestimations of blood alcohol level from the breath test results and also for the range of observed Blood-Breath Ratios.
PUTTING THE RATIO TO REST
Ronald L. Moore, Orange County Sheriff-Coroner, 320 N. Flower St., Santa Ana, California, 92703
The Blood-Breath Ratio is an often misused or misunderstood concept, both in court and in scientific literature. Because of the mathematical properties of ratios it is easy to manipulate or misinterpret the meaning of calculated blood-breath ratio. It is argued that the partition coefficient rather than the blood-breath ratio is the basis for breath testing results. Mathematical fluctuations in the blood-breath ratio are irrelevant to the accuracy of breath testing. To support this position the sources of deviation in the blood-breath ratio are examined, such as instrumental fluctuation and level of calculation, as well as various physiological factors which have also been alleged to have dramatic influence on the breath results. This is contrasted with the combined results of numerous correlation studies showing the actual agreement between real blood and breath tests.