91st SEMI-ANNUAL SEMINAR (Spring 1998)
CALIFORNIA ASSOCIATION OF CRIMINALISTS
May 6-9, 1998
PEPPERSPRAY: HISTORY AND DETECTION
Boyd G. Stephens, MD., Chief Medical Examiner, San Francisco, CA
The "peppers" as a food, are used by most civilizations around the world. The United States imports more than 60 million pounds each year, and produces more than that amount within the country. Pepper extracts are also used as repellants and as control agents. In California, there are no restrictions on the purchase or possession of pepper spray. The potential relationship to crime and or in - custody deaths exists and is of considerable concern in all jurisdictions.
This presentation will present the origin of the pepper extracts, some of the technology of manufacture, information on potential complications, including death, as well as methods for localizing and detecting the chemical. Some information on components and sources for reference standards is also included.
DIGITAL PHOTOGRAPHS - HOW TO PROVIDE THEM AND HOW TO USE THEM FOR DISCOVERY
Peter D. Barnett, Forensic Science Associates; Stephen A. Shaffer, Microdataware, Inc.
Photographs can be stored in a digital format either by scanning using desktop scanners, by having film processed commercially and images returned on disk, or by using digital cameras directly. The digital image has some advantages over traditional negatives or prints, but the use of digital images requires some planning on how to use these images or how to provide to others to use. There are many solutions to this problem using various types of cameras, film processing services, scanners, and software for digital image acquisition, storage, transmittal, processing and display. We will present practical requirements for using digital images as an alternative to traditional discovery formats, including recommendations for cameras, processing services, scanning, and image storage and retrieval. In order to be useful, a set of digitally stored images must be in a format compatible with standard software that is widely available (recommended formats are JPEG, GIF, BMP, or PCD), be accompanied by some sort of a descriptive annotation of each image, and have some procedure by which images may be previewed in "thumbnail" form. File management programs, such as Drag and File, have built in image viewing, printing and basic image manipulation facilities. Using Thumbs Plus, a widely used shareware program, simple image databases can be developed which include descriptive and searchable data fields along with the images. Images can be retrieved, viewed, and printed directly from the program. Paint Shop Pro or Photo finish, two inexpensive image processing programs, provide basic image manipulation capabilities, including cropping, enlargement, color and density correction, and translation from or between various digital formats. More advanced image manipulation software, like Photoshop allows more sophisticated image manipulation including various types of enhancements and special effects that may be used to extract useful data from an image.
ADDITIONAL FORENSIC SCIENCE APPLICATIONS OF FT -NIR SPECTROSCOPY
Robert D. Blackledge, Naval Criminal Investigative Service; Sharon A. Cooke, NIR Applications Spectroscopist, Perkin-Elmer Corporation, Beaconsfield, Bucks, United Kingdom
Heretofore, the primary application of near infrared reflectance spectroscopy has been for quality control analysis of agricultural products, pharmaceuticals, petroleum products, and foods. However, applications in additional areas are now made possible by the development of high-resolution FT-NIR instruments with greater measurement stability, incorporated internal standards for calibration, PC-control, and whose software have algorithms that facilitate simpler method development and sample comparisons.
A poster at the '98 AAFS meeting (and also on display at this CAC Seminar), detailed several applications related to controlled substances. Our oral presentation will detail further results from applications in the areas of paper comparisons, counterfeit currency detection, and the preliminary comparison of soil samples.
Initially, ten genuine and ten counterfeit twenty dollar bills were examined in an attempt to discriminate between different sources of paper. Following the success of this application, fifty seven different sources of commercial white paper, previously examined by other methods [Blackledge, R. & Gernandt, M. "The pH Pen: A Means of comparing Paper Products" JFS 38(1), 134-142 (1993).], were analyzed for discrimination purposes. Finally, eighteen soil samples were studied. In each case discrimination was attempted by the simple execution of the COMPARE algorithm. COMPARE looks at a library of spectra and produces a hit list with respect to a correlation value showing the closeness of fit. A repeat scan using different portions of the sample produced its stored spectrum as the closest hit in the majority, but not all, cases. Therefore a SIMCA (Soft Independent Modeling of Class Analogy) model was built for each of the above applications in order to better discriminate between the different types of samples. This is a chemometric approach using statistics to obtain information for qualitative analysis. The results from these applications to date are discussed here along with plans for future work in this area.
FT-RAMAN SPECTROSCOPY: AN EXPLOSIVE AND MIND-BLOWING TECHNIQUE FOR FORENSIC SCIENCE
Roel Ferwerda and Ben Garland, Nicolet Instrument Corporation
The use of FT-IR spectroscopy is well established in forensic laboratories. The specificity of the technique enables the user to do both qualitative of unknown samples and quantitative analysis of mixture and solutions. However, sample preparation is often necessary, making it unavoidable to handle dangerous materials or possibly changing the compound's properties. Therefore other analytical techniques for faster, easier and safer analysis are always under investigation.
Raman spectroscopy has not become a routine technique due to technical and application difficulties. Furthermore, the appearance of strong and broad backgrounds due to fluorescence, prevented the user from obtaining spectra of most real-life samples. Because the fluorescence signal is so much stronger than the Raman signal (up to one million times), even the fluorescence caused by trace contaminants may completely overwhelm the Raman spectrum of the compound. Therefore, the technique was virtually useless for routine analysis or quick screening of unknowns.
With the development of FT-Raman spectroscopy where NIR (1064 nm) lasers are used as the excitation radiation, these problems have largely been overcome. Also, due to the design of a FT instrument, alignment (sample positioning) is not an issue; the technique is extremely easy to use. Because NIR radiation is used and it is an emission technique, samples can be measured directly in the packaging material such as glass bottles or plastic evidence bags.
In this presentation, the specific nature of FT-Raman and its power as a screening technique will be shown for different illicit drugs (street samples) and explosive samples.
MENTORING: MULTIPLYING OUR LEADERSHIP INTO FUTURE GENERATIONS
Ronald G. Nichols, Forensic Analytical Specialties
I wish to address the topic of mentoring. If integrity is the key to leadership, mentoring is the key to multiplying that leadership throughout the generations.
As I have indicated so many times, we need to become more proactive in our quality assurance and quality control. Developing a laboratory with a solid reputation for good work will depend much on its quality assurance and quality control program. But this program cannot start with the proficiency test designed to test a skill. It has to start with the training and development of the individual to develop the critical thinking process necessary to make the decision to even use that skill. This requires a solid mentoring program.
Mentoring requires three simple ingredients, each as important as the other. The first is commitment on the part of all levels of management. This is not a commitment towards developing idiot proof quality assurance and quality control programs but rather a commitment towards developing such a proficient staff that idiots don't exist. The second is finding a mentor who is so people skilled and relationship minded that their chief goal and desire is to uplift others. and put them into a position to receive all the credit while at the same time protecting them from needless backlash. The third is to find a willing apprentice, someone who wants to learn. Develop them properly and you will have a satisfied, loyal, long-term employee, one who can now mentor others. The cycle begins.
FORENSIC APPLICATION OF FT-NIR IN CONTROLLED SUBSTANCE VALIDATION
Robert D. Blackledge, MS, Naval Criminal Investigative Service Regional Forensic Laboratory
This poster will demonstrate that FT - NIR can:
- Quickly, cheaply, and simply validate the identity of controlled substances and other chemical standards
- That for large seizures of multiple visually-similar package it can rapidly show whether their contents are all the same, and
- That rapid re-analysis of contraband items in evidence storage can easily verify that the contents have not been altered.
Method: Fourier transform near infrared spectroscopy examination of drug and chemical standards in glass or plastic packaging; simulation of pilfering and adulteration by weight-for-weight replacement of 10% of the drug standard with lactose followed by reexamination; and use of a robust hand held diffuse reflectance NIR probe for examination of kilo "bricks" wrapped opaque packaging. A Perkin-Elmer ldenticheck™ FT-NIR System utilizing Paragon ldenticheck Software was used for all experiments.
In the wake of the Tylenol® poisoning cases in the early eighties, Robert Lodder, who was then a chemistry graduate student at Indiana University, developed a sample holder that would hold intact capsules while an NIR instrument scanned the contents through the gelatin capsules. Lodder also developed a software program to analyze the NIR data and show if the capsules had been tampered (Lodder, R.A.; Selby, M.; Hieftje, a.M. "Detection of capsule tampering by near-infrared reflectance analysis." Anal. Chern. 59, 1987). The author wrote Lodder and asked if his NIR method might be able to quickly demonstrate if large drug seizures had subsequently been tampered with while in evidence storage. As a "worst case" scenario I proposed testing a drug sample in which 5% had been removed and replaced with an equivalent weight of KBr or NaCl. [Detection of KBr or NaCl should be difficult because not only are they white powders (as are pure cocaine, heroin, or methamphetamine), but they have virtually no absorption in the mid-IR range and therefore their overtones would not be seen in NIR.]
Lodder examined a sample of pure dextrose, and a sample of dextrose containing 5% KBr. Using his software program (a method of discriminate analysis), he found that the adulterated sample was more than 3 standard deviations beyond the measurement for the pure dextrose, and therefore would have been detected by his procedure.
THE PROGRAM AND SERVICES OF THE NATIONAL LAW ENFORCEMENT AND CORRECTIONS TECHNOLOGY CENTER
The National Law Enforcement and Corrections Technology Center (NLECTC) is a program of the National Institute of Justice (NIJ). NIJ, a research arm of the Federal Department of Justice (DOJ), has created an outreach program to state and local law enforcement and corrections agencies in the area of science and technology. The outreach program takes its form primarily in the operation of regional centers which become focal points for technology assistance to the corrections and law enforcement communities.
The NLECTC for the Western US is located in El Segundo California and is operated by the Aerospace Corporation, a non-profit company primarily servicing the Air Force space program for the last 35 years. Making use of an agreement between the Defense Department and DOJ, Aerospace is free to apply its 1700 scientists and engineers to problems encountered by law enforcement and corrections agencies.
The presentation outlines the services available, the skills mix which can be applied to the technical issues of the western region as well as some case histories and lessons learned from these case histories. The predominant case work has been in the area of video tape enhancement with audio work and other forensic laboratory work supported to a lesser extent.
The presentation will conclude with some words on how to obtain services from the NLECTC and the Western Region in particular and the extent to which the Center can support an agency for little or no cost to the agency.
G. Michele Yezzo, Forensic Scientist, S/A Supervisor Larry D. Harden, and S/A David Barnes; Office of the Attorney General, Ohio Bureau of Criminal Identification and Investigation and Capt. Michael L. Corwin, Bucyrus, Ohio, Police Department
Physical evidence is being demanded more by courts and juries in instances of violence. At the same time the media continues to give the perpetrators of these crimes more information about ways to dispose of the evidence. Therefore it is not only what we find it is what we don't find that may be of significance.
This case presentation is a combination of:
- observations and documentation via photographs and enhancement techniques of impressions found in snow near the scene of a multi victim homicide
- the investigative work which lead to locating the vehicle
- the examination of the subject vehicle
- the background information from references
- the information synthesized from these efforts which helped lead to a conviction.
Although snow is not a common medium for impression evidence in many parts of California, the methods used to seek information may be valuable to examiners working on impressions registered in any type of material. For those who work in areas where snow impressions are more likely, suggested methods of documentation will also be discussed.
G. Michele Yezzo, Forensic Scientist, S/A Supervisor Larry D. Harden, and S/A David Barnes; Office of the Attorney General, Ohio Bureau of Criminal Identification and Investigation and Capt. Michael L. Corwin, Bucyrus, Ohio, Police Department
Have you ever seen a tire impression left on the clothing of a hit-run victim? What about a positive impression registered on the inside of the garment which is more clearly recorded than the one on the exterior?
This presentation illustrates physical evidence from the vehicular manslaughter of a police officer struck down while directing traffic. Critical evidence in this case included a positively registered tire impression on the inside surface of the deceased's pantleg and pattern injuries as well as various other types of trace evidence. Documentation and use of this evidence will be discussed.
EFFECTS OF VARIABLES ON THE APPEARANCE OF GUNSHOT DEPOSITIONS USING 9MM LUGER AMMUNITION
Ronald G. Nichols, Forensic Analytical Specialties
Reconstruction of the circumstances in which a shooting took place is a common practice in many forensic laboratories. The analyst is asked to examine various elements of a shooting and render an opinion as to the muzzle to target distance from which the shot or shots may have been fired. This study examines the effects of different variables on the appearance of gunshot depositions on targets when using 9mm luger ammunition.
The various features of the deposition patterns which were examined include the presence of smoke, the presence of a smoke gradient, the powder pattern diameter, the powder pattern density and distribution, and the maximum distance at which significant amounts of powder were deposited onto a target. The variables examined include the muzzle to target distance, the barrel length, the type of ammunition used and the type of target material.
Two firearms selected for this study were both IMI Uzi's imported by Action Arms, one a pistol with a four and one-half inch barrel and one a carbine with a twenty inch barrel. Four types of ammunition were used including two with flattened ball powder, one with flake powder and one with disc powder. Five different target materials were used including cotton flannel, acetate, denim, fleece and 90 pound card stock. Test targets were obtained by firing the firearm from a stable rest at distances including at least some of the following: 1, 3, 6, 9, 12, 18, 24, 30, 36, 48, 60, 72, 84 and 96 inches. Prior to the shooting of each test pattern, a dry patch was pulled through the barrel to clean it.
All test shots with the carbine at 12" muzzle to target distance produced smoke (n=11) whereas only half the shots with the pistol at the same distance produced smoke (n=12). The presence of a smoke gradient also appeared to be barrel length dependent as 11 of 12 test shots using the carbine produced a gradient at 3" muzzle to target distance and 4 of 12 shots produced a gradient at 6". For the pistol, these figures were 7 of 12 and 0 of 12 respectively. The effects of ammunition type and fabric are less readily apparent but certain combinations of ammunition and target material did produce widely variant results.
With some exceptions, as muzzle to target distance increased, the powder pattern diameter increased. The test shots from the carbine produced a consistently tighter pattern than similar shots from the pistol as has been reported elsewhere. Pattern diameters showed marked variability with regards to ammunition type as well as fabric.
Powder pattern density and distribution was measured using a circular plotting grid and appeared to be affected by all variables: muzzle to target distance, barrel length, powder type and target material. As the muzzle to target distance increased, the distribution and density of the powder pattern became less and less distinctive making a distinction between patterns based on this criteria alone quite difficult. This was especially evident at distances of 24 inches and beyond. Ammunition type was a significant factor as the Winchester brand ammunition with flattened ball powder consistently displayed a denser pattern than any of the other ammunition types. With regards to target material, those materials with a tighter weave produced a more dense pattern.
The distance at which significant amounts of powder were deposited onto the target differed for the different types of ammunition. Morphology seemed to be the key as the more aerodynamically sound shape of the flattened ball powder traveled further than the disc shape which in turn traveled further than the flake shape. At the closer distances in which there is a marked distinction among both smoke and density and distribution of powder, it may be possible to produce a tighter range of possible muzzle to target distances from which a particular shot may have been fired. However, at intermediate to longer distances, i.e., greater than 12 inches, when pattern diameter becomes the most distinctive feature, the opportunity for error appears to be greater. Ideally, to obtain the best results, this study confirms the results of earlier studies in that the weapon, similar ammunition and similar target material be used when attempting to reconstruct a muzzle to target distance.
Acknowledgements: This study was funded through the A. Reed and Virginia McLaughlin Endowment. I also wish to thank Curtis Sato and Jennifer Hannaford for their assistance in the many test fires that were conducted.
A TWIST OF THE WRIST
Nancy D. McCombs, Fresno Regional Laboratory
A cartridge case ejection pattern on the left side of a shooter is indicative of a top ejecting pistol as opposed to one that ejects to the right. However, the recent trend of holding a pistol horizontally when firing might be expected to influence the cartridge case ejection pattern.
Top ejecting and right ejecting pistols were fired from vertical and horizontal positions using various ammunition in order to determine the effect of the cartridge case distribution patterns.
"MAN DOWN": EARLY INFLUENCES ON EXPECTATIONS FOR SCIENTIFIC CRIME INVESTIGATIONS
Duayne J. Dillon, D. Crim., Document Services
The expectations of clients of scientific investigators were certainly affected by accounts of successful applications of such types of investigations. Early accounts by proponents are to be found in scientific journals, the popular press and books by "true crime" writers. Interestingly, there has been little in the way of critical assessment of these early accounts, even though contemporary texts often contain references to early "principles" or abbreviated accounts of these pioneering cases.
While the passage of years has, in many instances, precluded the verification of many reports of rather amazingly successful applications of "science" to criminal investigations, an intercomparison of differing descriptions of the same case can lead to some surprising conclusions. While exposed discrepancies can, in some cases, be attributed to the "literary license" of authors, in other instances we are faced with evidence extensive exaggeration if not fraud.
This paper discusses illustrations of a plaster cast appearing in five books with differing accounts as to its source. The cast in question is attributed to either Edmond Locard of Lyon, France or Alphonse Bertillon of Paris. The intercomparison of accounts reveals that one account is entirely fictitious and the cast, itself, did not originate in the described manner.
THINGS I HAVE ALWAYS WANTED TO SAY TO PROSECUTION EXPERTS AND THINGS I HAVE ALWAYS WANTED TO SAY TO DEFENSE EXPERTS
John I Thornton. Forensic Analytical Specialties, Inc.
As scientists we are all impartial, dispassionate seekers of the truth. As forensic scientists we are hopefully still that, but the reality is that we are also the handmaidens of a system that places pressure on us to please our masters. Over the past 35 years, the author has been the creature of both the prosecution and the defense, and, as a result of this experience, certain recurring themes have presented themselves. When called by the prosecution, the author has often wanted to shackle the defense consultant and discuss with him on several points of which he is obviously unaware, (to be charitable), or ignorant, (to be less kind). When called by the defense, the author has often wanted to do the same to the prosecution expert. The author would like to take this opportunity, hopefully in a nice way, to vent his spleen.
RAPID mtDNA TYPING USING IMMOBILIZED SEQUENCE-SPECIFIC OLIGONUCLEOTIDE (SSO) PROBES: ADVANTAGES AND LIMITATIONS
R. Reynolds, J Varlaro, K. Walker, M Alavaren, J Griggs; Roche Molecular Systems
Mitochondrial DNA (mtDNA) has unique features that make it a potentially useful target for the analysis of telogen hairs, mass disaster and missing person remains, and other biological samples that are too small or too degraded to be analyzed by conventional DNA analysis. One approach' to typing mtDNA is DNA sequence analysis of multiple amplified sections of the hypervariable region of the mitochondrial genome. Another method, developed by Stoneking et al., uses a panel of 23 SSO probes in a dot blot format. Both of these procedures and requisite data analysis are very time-consuming but they provide a substantial amount of information. To provide a faster, less expensive method for mtDNA analysis, we developed an immobilized sequence-specific oligonucleotide (SSO) probe-based typing system. Using an optimized reaction mix containing AmpliTaq Gold DNA polymerase, a 415 bp portion of hypervariable region II (HVII) is amplified. A panel of 16 SSO probes immobilized on a single strip is used to determine the HVII mitotype. It is possible to type and interpret the results of up to 40 samples in approximately 2.5 hours post amplification compared to 2 or more days for obtaining and analyzing DNA sequencing and forward dot blot results. We typed 689 unrelated individuals from 4 population groups and sequenced ~ 100 samples. The discriminatory potential of this system is comparable to DIS80 and HLA DQAl, making it a useful screening method. We have typed and sequenced multiple shed and plucked hairs from over 10 people. We found that the majority of these individuals had one or more hairs with a different mitotype than the mitotype obtained from their blood, saliva, and other hairs. Regardless of the method of analysis, heteroplasmy must be considered when interpreting results.
FOOTLOOSE AND FAT-FREE: UNUSUAL APPLICATIONS OF DNA TYPING
Mary M Hong, Orange County Sheriff-Coroner
There is no question that DNA typing has had a significant impact on the ability to analyze evidence. Not only has DNA typing been shown to be much more sensitive, both in terms of quantity and quality of samples, its presence in all nucleated cells of the body has allowed it to be applied to a broader range of evidence than conventional protein typing. I will present some unusual types of evidence where DNA typing has been applied to address case issues.
FORENSIC ODONTOLOGY MEETS THE NEW MILLENNIUM-SALIVARY AND DENTAL DNA EVIDENCE
Dean Hildebrand, Ph.D., and Co-Author David Sweet, DMD, Ph.D., Bold Lab, Vancouver, British Columbia, Canada
Forensic dental evidence is becoming increasingly important in the successful investigation of crimes. Human bite marks determined to have low forensic significance as physical evidence are now recognized as valuable sources of biological evidence. Salivary DNA can be recovered from bitten objects and human skin. Teeth are the hardest substances in the human body. They shield valuable DNA evidence from postmortem changes. DNA can be recovered and successfully typed to identify a victim, determine the origin of fragments, or for comparison to other DNA evidence at the crime scene. This paper will highlight the ongoing research and forensic casework of the Bureau of Legal Dentistry Laboratory in Vancouver, Canada. Advances in PCR-based typing at STR loci of DNA from saliva and teeth will be discussed in addition to protocols for the recovery, handling, and analysis of dental DNA evidence.
A STUDY OF HARDY-WEINBERG EQUILIBRIUM, LINKAGE EQUILIBRIUM, AND POPULATION STRUCTURE IN HISPANICS USING SEVEN GENETIC MARKERS
Donald T Jones, San Bernardino Sheriff's Dept., Scientific Investigations Division
Blood samples from two hundred sixty Hispanic subjects were analyzed for seven genetic markers commonly used in forensic science: esterase D (EsD), erythrocyte acid phosphotase (AcP), phosphoglucomutase (pGM), adenosine deaminase (ADA), adenylate kinase (AK), group specific component (Gc) and DQ alpha. The samples were divided into three groups: 100 Mexicans, 88 El Salvadorans, and 72 Guatemalans.
There were no significant Hardy-Weinberg Equilibrium (HWE) deviations at the seven loci in each of the three groups except for the El Salvadoran Gc locus (p = 0.05). The Guatemalan group was monomorphic for a single adenyl ate kinase allele. The El Salvadoran group had one significant linkage correlation (p = 0.01) between EsD and ADA; however, heterozygosity variance tests for each group showed no significant linkage among loci.
In the combined Hispanic sample there was no significant deviation (p > 0.05) from HWE at each locus. Twenty one two-locus linkage correlation tests revealed one pair (EsD/AcP) with a significant correlation (p = 0.05); the heterozygosity variance test showed no significant correlations among the seven loci. An FST value of 0.0109 (p = 0.01) for EsD may indicate the presence of population structure; however, none of the other six loci (FST < 0.01) indicated significant (p > 0.05) population structure.
THE USE OF TRACE EVIDENCE IN BLOOD SPATTER INTERPRETATION
Faye Springer, Sacramento County Laboratory o/Forensic Services, 4800 Broadway, Sacramento, CA 95820
(No abstract available)
IMPULSE AND MOMENTUM OF IMPACT BLOODSTAIN PATTERNS
Patricia Lough and Co-Author Javier Torner, San Bernardino Sheriff's Dept.
Objective: To enhance the knowledge of the bloodstain pattern analyst relating to impact pattern causes and effects. Analysts will have the use of alternate terminology to aid in more accurately' describing impact patterns. An inconsistency exists in the terminology used among bloodstain pattern analysts. The literature interchangeably uses terms including velocity, energy and force of impact to describe the cause and effects of impact stain patterns, but they do not answer what causes the patterns. This paper discusses the concepts of momentum transfer and impulse as an alternative to explain the similarities and differences of bloodstains produced in different situations.
Velocity and mechanical or kinetic energy are not conserved in a collision and these terms are inadequate when describing the product of a bloodstain pattern. Momentum is conserved in a collision. Both the velocity and mass of a moving object are determining factors in the initial momentum. This momentum is transferred in a collision over time. The resulting size of the bloodstain in the pattern is related to the change in momentum, i.e. impulse, which is defined as the product of the average force and time of contact.
Velocity, energy and force are important factors in the study of impact spatter patterns. However, because they are not conserved quantities, they cannot be used to uniquely characterize impact spatter patterns. The terms low, medium or high momentum transfer of impulse patterns more precisely describe those now called low, medium or high energy/velocity impact patterns.
OF FACTS AND STONE
Anita K. Y Wonder, MA, Wonder Institute, Carmichael, CA
An excellent discussion of terminology, Impulse and Momentum of Impact Bloodstain Patterns, was presented by Patricia Schechter Lough, MS, at the 50th Annual Meeting of the AAFS. A semantics controversy has been acknowledged by informed scientists for years, yet science principles upon which bloodspatter terms are based are usually accepted without question. Such postulate acceptance may not be warranted.
In 1903 a verse was included in a science manuscript, La Science et J'Hypothese. "Science is built up with facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house." Jules Henri Poincare (1854-1912). Poincare's quote provides a new light by which we should evaluate facts applied to bloodstain pattern analysis. How does velocity actually form and disperse blood drops? What is the rationale behind drop size/distance traveled, terminal velocity, and surface tension as they apply to violent bloodshed? Some science precepts necessary to understand dynamic validity, or lack of, were discovered between 1950 and 1984, yet most defining citations date from before 1939. Are early facts adequate upon which to build a modern science or are they an irrelevant pile of stones used only to defend out-of-date concepts?
PITFALLS IN BLOODSTAIN PATTERN INTERPRETATION
Jerry Chisum, California Criminalistics Institute, Sacramento, CA 95820
There are four areas that the bloodstain analyst needs to be concerned about as failure to do so results in misinterpretation of "bad science":
- Assuming "all is the same"
- Mind set
- Lack of background knowledge
We will discuss and illustrate examples in each of these areas.
NW INNOCENCE PROJECT
(No abstract available)
Pat Grant, Forensic Science Center, Livermore National Laboratory
For the past several years, counterfeit currency of exceptionally high quality has been interdicted by law enforcement authorities. Identifying the source(s) of illicit currency is a primary focus of the U.S. Secret Service, and the highest quality counterfeit yet detected has been designated the "Supernote." Between 1993-1996, the Livermore Forensic Science Center participated in a federal interagency task force to perform forensic analyses of this counterfeit currency for geolocation information. A diverse suite of multidisciplinary technologies was applied to the problem by the FSC and other Livermore investigators. Chemical, physical, and biologic methods for the analyses and characterization of the paper and various ink formulations will be described.
APPLICATIONS OF ENERGY DISPERSIVE X-RAY MICROANALYSIS TO TONER MATERIALS FROM PHOTOCOPIERS
Goldie Tandon, Dept. of Astronomy and Space Science, Punjabi University Pariala, India
A study has been made of the photocopy toners used in photocopying processes to determine the inorganic contents present using EDXA. A collection of 27 photocopy toners used in various models and brands of photocopiers from 8 manufacturers have been examined using Energy Dispersive X-ray Microanalysis System combined with Scanning Electron Microscope.
Discrimination of toner samples made on the basis of significant qualitative differences in the x-ray spectra produced has shown the categorization of samples as:
- Those with elements present in major amounts, in order of increasing energy.
- Those with elements present in minor amounts.
- Those with elements present in trace amounts.
Differences in relative amounts of elements detected between raw and processed toner and significant variation in the loading of the base papers has been noted. Moreover, a clear distinction between mono component and dual component process toners has been made. A reference collection of spectra of raw toners has been compiled. EDXA has proved to offer a high degree of discrimination which together with FTIR can be recommended as a means of providing reliable identification of inorganic elements and polymers used in toners. Though the instrumentation is quite expensive, SEM combined with EDXA is an excellent analytical system which is least destructive, fast and produces a good quality spectra.
GROSSMONT COLLEGE EVIDENCE TECHNICIAN COURSE
(No abstract available)
CRIMINAL PROFILING: THE DEDUCTIVE METHOD & SADISM
Brent E. Turvey, MS., Knowledge Solutions LLC
The subject of this presentation is the use of the Deductive Criminal Profiling method to help understand offender Modus Operandi, Signature, and other behavioral aspects of the crime scene. The purpose of this presentation will be to demonstrate the Deductive Criminal Profiling method's usefulness in suspect generation during the investigative process and then informing the trier of fact at trial.
The Deductive method requires a minimum of four stages in its development. The first three stages are the Forensic Analysis, Victimology, and the Crime Scene Characteristics, in that order. The fourth stage is the information deducted from the first three, the Offender Characteristics. By virtue of its reliance on a full exploitation of the physical evidence in a crime scene, the Deductive method places a strong emphasis on competent forensic reconstructions, wound pattern analysis, and teamwork between disciplines.
This presentation will show the usefulness of the Deductive method by using two case examples where the behavioral evidence of a crime has been used to suggest Sadism.