Trends in explosive contamination

This study sought to assign a rough order of magnitude for the amount of explosive residue likely to be available in real-world searches for clandestine explosives. A variety of explosives (TNT, TATP, HMX, AN, RDX, PETN) in various forms (powder, flake, detonating cord, plastic) were carefully weighed or cut into containers, and the amount of residue inadvertently remaining on the work area, hands, or containers was quantified. This was used to evaluate the spillage potential of each explosive. The adhesion of each explosive to a glass surface was quantified from amount of explosive adhering to the inside of a glass vial into which the explosive had been placed and then removed by vigorous tapping. In powdered form, most of the explosives--TNT, PETN, RDX, HMX, and TATP--exhibited similar spillage and adhesion to glass. However, PETN as sheet explosive and plasticized RDX (C-4), showed very little potential to contaminate surfaces, either by spillage or adhesion to glass.     

A novel multiplex PCR system consisting of Y-STRs DYS441, DYS442, DYS443, DYS444, and DYS445

We have developed a new sensitive multiplex PCR system consisting of five male-specific and polymorphic tetranucleotide STRs--DYS441 (GDB: 10013873), DYS442 (GDB: 10030304), DYS443 (GDB: 10807127), DYS444 (GDB: 10807128), and DYS445 (GDB: 10807129) on the Y chromosome. Fifty pg DNA per 10 microL reaction volume was required for the correct typing of five STRs. Using this system, the five Y-STRs were correctly typed from blood and semen stains that had been stored for several years at room temperature.     

Writer identification using hand-printed and non-hand-printed questioned documents

Several federal district court judges have recently referred to the purported lack of information on the proficiency of forensic document examiners (FDEs) in identifying writers of hand-printed documents. In order to provide the necessary information, we have re-analyzed data on writer identification that were collected in 1996 from 90 forensic document examiners and 34 laypersons. These data were used previously to assess the proficiency of FDEs using handwritten documents in several different types of writing. In the new analysis we separated data on hand-printed (HP) documents from data on non-hand-printed (NHP) documents and compiled error rates and statistics in each category. The main findings are: (1) whether or not the documents were hand-printed, the performance of FDEs was much better than that of laypersons; (2) statistical tests found no difference between the data provided by the FDEs in the HP and NHP categories; (3) statistical tests found no difference between the data provided by laypersons in the HP and NHP categories; and (4) statistical tests found differences between the data provided by the FDEs and the laypersons in both the HP and NHP categories. Similar results were obtained when hand-printed documents were compared to cursive documents and when cursive documents were compared to non-cursive documents. All the evidence indicates that in our proficiency test the performance of FDEs in writer identification was much better than the performance of laypersons in each one of the following document categories: (1) hand-printed; (2) non-hand-printed; (3) cursive; and (4) non-cursive.     

Lifetime distributional effects of Social Security retirement benefits

This article presents three measures of the distribution of actual and projected net benefits (benefits minus payroll taxes) from Social Security's Old-Age and Survivors Insurance (OASI) for people born between 1931 and 1960. The results are based on simulations with the Social Security Administration's Model of Income in the Near Term (MINT), which projects retirement income through 2020. The base sample for MINT is the U.S. Census Bureau's Survey of Income and Program Participation panels for 1990 to 1993, matched with Social Security administrative records. The study population is grouped into 5-year birth cohorts and then ranked by economic status in three ways. First, the population is divided into five groups on the basis of individual lifetime covered earnings, and their lifetime present values of OASI benefits received and payroll taxes paid are calculated. By this measure, OASI provides much higher benefits to the lowest quintile of earners than to other groups, but it becomes less redistributive toward lower earners in more recent birth cohorts. Second, people are ranked by shared lifetime covered earnings, and the values of shared benefits received and payroll taxes paid are computed. Individuals are assumed to split covered earnings, benefits, and payroll taxes with their spouses in the years they are married. By the shared covered earnings measure, OASI is still much more favorable to persons in the lower income quintiles, although to a lesser degree than when people are ranked by individual covered earnings. OASI becomes more progressive among recent cohorts, even as net lifetime benefits decline for the entire population. Finally, individuals are ranked on the basis of their shared permanent income from age 62, when they become eligible for early retirement benefits, until death. Their annual Social Security benefits are compared with the benefits they would have received if they had saved their payroll taxes in individual accounts and used the proceeds to buy either of two annuities that provide level payments from age 62 until death: a unisex annuity that is based on the average life expectancy of the birth cohort or an age-adjusted annuity that is based on the worker's own life expectancy. On the permanent income measure, OASI is generally more favorable to people in higher income quintiles. Moreover, it is particularly unfavorable to those in the lowest quintile. Because people in the lowest quintile have a shorter life expectancy, they receive OASI benefits for a shorter period. This group would receive greater benefits in retirement if they invested their payroll taxes in the age-adjusted annuity. OASI is more favorable to them than the unisex annuity, however, OASI is becoming more progressive in that the net benefits it provides drop more rapidly among higher income quintiles than lower ones. This article also examines how OASI affects individuals by educational attainment, race, and sex. On both the lifetime covered earnings and the permanent income measures, OASI is more favorable to workers with less education and more favorable to women. The results by race and ethnicity are mixed. When people are ranked by the present value of their shared lifetime covered earnings, OASI appears more favorable to non-Hispanic blacks and Hispanics than to non-Hispanic whites. When people are ranked by shared permanent income in retirement, however, OASI produces negative returns for both non-Hispanic blacks and non-Hispanic whites in the most recent birth cohorts, with non-Hispanic blacks faring relatively worse. The changes across cohorts occur partly because of changes in tax rates and benefits, but more importantly because of changing demographics and earnings patterns of the workforce. Of particular importance is the increasing share of beneficiaries who receive worker benefits instead of auxiliary benefits as wives or widows. OASI benefits are based on the lifetime covered earnings of current or former married couples, as well as on earned retirement benefits of individuals. The reduced importance of auxiliary benefits (due to the higher lifetime covered earnings of women) and the increased proportion of divorced retirees make OASI more progressive--even as net benefits decline--for current and future cohorts than for cohorts who retired in the 1990s. Analysis of these findings suggests that simulations of policy changes in Social Security must take into account the decreasing importance of auxiliary benefits across birth cohorts and the complex changes in individuals' marital histories.     

Once again: risk of injury caused by blank pistols

The nature and extent of the use of blank pistols in Hamburg (according to the Hamburg crime statistics about 300 to 400 such cases per year; 34 cases involving head and neck wounds from 1989 to 1999 were investigated at our institute; among these 8 suicides, no homicide) as well as patterns of injuries caused by close distance blank pistol shots were analysed. 7 of these cases are described in detail. The results of our studies corroborate the warning statements made by many criminological and medico-legal experts regarding the danger inherent in these allegedly harmless weapons. Blank cartridge pistols can, when shot from a close distance, cause most severe injuries involving penetration into body cavities and bodily organs (especially in the head and neck), and even perforation of the skull. Therefore, we call for a much stricter control of weapons of this kind.     

Combined homicide-suicide in Galveston County

Combined homicide-suicides have been classified based on the psychopathology of the perpetrator and the nature of the relationship between perpetrator and victim(s). To further understand the nature of this tragic phenomenon and to test the validity and practicality of a previously suggested classification system, investigators systematically collected data on all combined homicide-suicide events that occurred in Galveston County, Texas over a continuous 18-year period (n = 20). The most common psychopathological finding for perpetrators was high serum alcohol levels that suggested intoxication. Most combined homicide-suicides fell into one of the relational categories and most of these, as predicted, were of the consortial type, possessive subtype. As expected, due to the small sample size, the less common types of combined homicide-suicide were not represented in this sample.     

Glucose and lactate in vitreous humor compared with the determination of fructosamine for the postmortem diagnosis of diabetes mellitus

Diabetes mellitus is a chronic metabolic illness responsible for a great number of deaths. In postmortem diagnosis, because of the difficulty involved in interpreting blood glucose levels and relatively nonspecific pathologic features, biochemical markers in vitreous humor are useful. The aim of this study was to compare the results obtained for the combined determination of lactate and glucose with fructosamine levels recorded in the vitreous humor of two diagnostic groups (one diabetic and the other nondiabetic). The authors intended to ascertain the capacity of different markers measured in vitreous humor to diagnose diabetes mellitus. Fifty-one cadavers (mean age, 58.7 years; standard deviation, 17.09) were studied. The mean postmortem interval was 16.4 hours (standard deviation, 9.05). Cases were assigned to two diagnostic groups according to whether they were previously diagnosed as either diabetic or nondiabetic. Statistically significant differences for glucose, fructosamine, and the sum values of glucose and lactate were found between the two diagnostic groups. The highest levels were obtained in the group of cases with a previous diagnosis of diabetes mellitus. After the comparison of receiver operating characteristic curves, the sum values of glucose and lactate in vitreous humor is a better predictor of antemortem diabetes mellitus than the fructosamine.