Individuality of handwriting

Motivated by several rulings in United States courts concerning expert testimony in general, and handwriting testimony in particular, we undertook a study to objectively validate the hypothesis that handwriting is individual. Handwriting samples of 1,500 individuals, representative of the U.S. population with respect to gender, age, ethnic groups, etc., were obtained. Analyzing differences in handwriting was done by using computer algorithms for extracting features from scanned images of handwriting. Attributes characteristic of the handwriting were obtained, e.g., line separation, slant, character shapes, etc. These attributes, which are a subset of attributes used by forensic document examiners (FDEs), were used to quantitatively establish individuality by using machine learning approaches. Using global attributes of handwriting and very few characters in the writing, the ability to determine the writer with a high degree of confidence was established. The work is a step towards providing scientific support for admitting handwriting evidence in court. The mathematical approach and the resulting software also have the promise of aiding the FDE.     

Blind field test evaluation of Raman spectroscopy as a forensic tool

Analytical instrumentation for Raman spectroscopy has advanced rapidly in recent years to the point where commercial field-portable instruments are available. Raman analysis with portable instrumentation is a new capability that can provide emergency response teams with on-site evaluation of hazardous materials. Before Raman analysis is accepted and implemented in the field, realistic studies applied to unknown samples need to be performed to define the reliability of this technique. Studies described herein provide a rigorous blind field test that utilizes two instruments and two operators to analyze a matrix that consists of 58 unknown samples. Samples were searched against a custom hazardous materials reference library (Hazardous Material Response Unit (HMRU) Spectral Library Database). Experimental design included a number of intentionally difficult situations including binary solvent mixtures and a variety of compounds that yield medium-quality spectra that were not contained in the HMRU library. Results showed that over 97% of the samples were correctly identified with no occurrences of false positive identifications (compounds that were not in the library were never identified as library constituents). Statistical analysis indicated equivalent performance for both the operators and instruments. These results indicate a high level of performance that should extrapolate to actual field situations. Implementation of Raman techniques to emergency field situations should proceed with a corresponding level of confidence.     

Attitudes of people with disabilities toward physician-assisted suicide legislation: broadening the dialogue

This article presents the methods, findings, and implications of a participatory action research project that attempted to shed additional light on the debate over death with dignity (DWD) or physician-assisted suicide (PAS) legislation. In-depth, qualitative interviews with forty-five physically disabled residents of the San Francisco Bay Area, conducted by others with disabilities, revealed a wide breadth of opinions about and attitudes toward such legislation. For close to half of the participants, the desire for autonomy in making end-of-life decisions was a primary concern, yet fear that PAS legislation could violate this autonomy in various ways was a deep concern as well. Also reported were widespread accounts of disability-based discrimination and frequent expressions of fear about openly discussing positions that diverge from the official, publicly held opinions of disability leaders who oppose such legislation. The findings support those of a recent Harris poll demonstrating considerable diversity of opinion about PAS legislation among people with disabilities. The findings further suggest the need for additional research on the apparent disjunction between the diversity of attitudes held by those interviewed and the more unified position taken by many disability activists. Use of the study findings to promote greater dialogue within the community and to better position people with disabilities to take their place at the policy table also is discussed. In addition, the findings are seen as reinforcing the need for the public health community to become more engaged in this central ethical debate.     

A highly polymorphic STR locus in Cannabis sativa

We report on the first short tandem repeat (STR) locus to be isolated from the plant Cannabis sativa. The STR locus, isolated by a hybrid-capture enrichment procedure, was found to contain a simple sequence repeat motif of 6 bp. This 6 bp repeat motif showed no variation in repeat length but with minor variations in repeat unit sequences. The data show the locus to be highly polymorphic with the number of repeat units ranging from 3 to 40 in 108 screened samples. The observed heterozygosity was approximately 87.04%. The forward and reverse primers (CS1F and CS1R) produced no PCR products in cross-reaction study from 20 species of plants, including highly related species such as Humulus japonicus and Nicotiana tabacum. This hexanucleotide repeat DNA locus could be used to identify cannabis samples and predict their genetic relationship as the test is specific to C. sativa and is highly reproducible.     

Allele frequencies and haplotypes of six new Y-specific STR loci in Koreans

Six Y-specific STR loci, DYS434, DYS435, DYS436, DYS437, DYS438, and DYS439 were analyzed in 300 unrelated Korean males using single multiplex PCR system.     

Population genetics of nine STR loci: TH01, TPOX, CSF1PO, vWA, FESFPS, F13A01, D13S317, D7S820 and D16S539 in a Korean population

Allele frequencies for nine STR loci namely, TH01, TPOX, CSF1PO, vWA, FESFPS, F13A01, D13S317, D7S820 and D16S539 were obtained from a sample of 437 unrelated individuals living in Chungcheong-do, South Korea.