Comparison of age estimated from degree of racemization of aspartic acid, glutamic acid and alanine in the femur

Aspartic acid (Asp) is generally used for estimation of age by measuring the degree of racemization. For other amino acids, however, there are few reports regarding the usefulness of the degree of racemization for the estimation of age. Accordingly, in this study using the femur (obtained from 21 cadavers) as the specimen, we measured the degree of racemization of glutamic acid (Glu) and alanine (Ala) along with Asp in the total amino acid (TAA) fraction as well as in acid-insoluble collagen-rich (IC) and acid-soluble peptide (SP) sub-fractions. We compared the degrees of racemization of each amino acid and the accuracy of the ages estimated from them. The degree of racemization and the reaction rate of racemization were ranked in the order of Asp > Glu > Ala in the TAA and IC fractions, but Asp > Ala > Glu in the SP fraction. It is noteworthy that the degrees of racemization differed between the three amino acids depending on the fraction tested. The correlation coefficient (r) between the degree of racemization and the chronological age was higher in the SP than in the TAA or IC fraction. Among three amino acids, Asp showed the highest correlation coefficient as predicted. The present study confirmed that Asp from the SP fraction is the best indicator for age estimation using racemization rates.     

The evaluation of the extent of transporting or "tracking" an identifiable ignitable liquid (gasoline) throughout fire scenes during the investigative process

Tests have determined that boots or shoes of individuals at a fire scene do not transport sufficient contaminants ("tracking") through the fire scene to produce a positive laboratory result for the presence of gasoline in a fire scene that was not present at the time of the fire. Questions about the validity of forensic laboratory results have been raised on the basis that low-level gasoline residues detected in the laboratory samples could have been the result of transporting the residue by footwear contaminated from the fire scene ("tracking"). The data collected in this study establish that "tracking" does not lead to false-positive laboratory results. Canines trained and experienced in the detection of trace ignitable liquid residues were also utilized in this study. The canine results confirmed that properly trained canines show a higher sensitivity than do standard ASTM laboratory techniques for fire debris analysis. In a few cases, canines responded to contamination, but laboratory testing (which is the definitive indicator) did not produce positive results.     

Female suicides in Diyarbakir, Turkey

The aim of this study was to investigate the methods used and demographic data of women suicides by examining postmortem investigation and autopsy reports from the Branch of the Council of Forensic Medicine in Diyarbakir Province, Turkey, between 1996 and 2001. Fifty-eight percent (174/302) of suicides were females and 42% (128/302) were males. The suicide rates were similarly higher for females than for males (2.6 and 1.8 per 10,000 population, respectively). Over half of female suicides (56.3%) occurred in those under 20 years of age. The most common suicide method for women was hanging (32.2%), and for men was firearms (51.7%), but for women younger than 20 years the most frequent method was firearms. Among the female suicides, five (2.8%) were known to have attempted suicide at least once in the past. Twenty-nine women (16.7%) were documented to have any psychiatric illness. None of the women had a history of drug or alcohol abuse. A suicide note was found in only six cases (3.4%). The predominant suicide motive was family problems (in 32% or 56/174). The higher rate of suicide in females than in males, and the absolute female predominance in suicides in Diyarbakir, Turkey, are in contrast to most of the medical literature and statistical information about suicide rates by country, in which suicide rates are usually higher among males.     

Organic explosives analysis using on column-ion trap EI/NICI GC-MS with an external source

In this study, a standard method by gas chromatography coupled with mass spectrometry (GC/MS) for the analysis of classical organic explosives was developed. This method was validated in the EI mode, based on the XPT 90-210 standard method. Detection limits (LOD) and quantitation limits (LOQ) were both determined using electronic impact (EI) and negative ion chemical ionization (NICI) modes. These were compared and results showed that in the NICI mode, detection limits were lower than in the EI mode, thus NICI mode appeared to be the best way to analyze nitrate esters. Results of ion trap MS detection were then compared with those obtained in a previous study with single quadrupolar technology. Major ions that were obtained using ion trap MS detection in these two modes were reported.     

Priming Unconscious Racial Stereotypes About Adolescent Offenders

Two studies examined unconscious racial stereotypes of decision makers in the juvenile justice system. Police officers (Experiment 1) and juvenile probation officers (Experiment 2) were subliminally exposed to words related to the category Black or to words neutral with respect to race. In a presumably unrelated task, officers read 2 vignettes about a hypothetical adolescent who allegedly committed either a property crime (shoplifting from a convenience store) or an interpersonal crime (assaulting a peer). The race of the offender was left unstated and the scenarios were ambiguous about the causes of the crime. Respondents rated the hypothetical offender on a number of traits (e.g., hostility and immaturity) and made judgments about culpability, expected recidivism, and deserved punishment. They also completed a self-report measure of conscious attitudes about race. As hypothesized, officers in the racial prime condition reported more negative trait ratings, greater culpability, and expected recidivism, and they endorsed harsher punishment than did officers in the neutral condition. The effects of the racial primes were not moderated by consciously held attitudes about African Americans. The implications of the findings for racial disparity in the juvenile justice system and for changing unconscious stereotypes were discussed.