A quantitative comparison of smokeless measurements

Measurements of the type and concentration of propellant and stabilizer additives in smokeless gunpowder are used by forensic scientists investigating the source of explosives and by military laboratories assuring the safety and efficacy of munitions. The National Institute of Standards and Technology recently assessed the state-of-the-practice of smokeless powder measurements through an international measurement comparison exercise. We here present results provided by the five participants (of 20 total) reporting quantitative as well as qualitative values for two handgun reloading powders. All five of these participants reported values for nitroglycerin (NG), ethyl centralite (EC), diphenylamine (DPA), and N-nitrosodiphenylamine (NnDPA). Several participants additionally reported the concentrations of secondary stabilizer decomposition products. The unstable NG propellant additive appears to be more susceptible to method-specific calibration biases then are the stabilizer additives. All results from one participant were strongly biased relative to those of the other four. The within-participant measurement uncertainties for all analytes were self-reported to be 1 to 5% relative; among the four concordant participants, the measurement ranges are 5 to 10% relative. There was little consistency among the participants as to what components of measurement variance were included in their uncertainty statements. A discussion of the certainties in these measurements and factors that affect the accuracy of gunpowder additive determinations is presented.     

A novel method for the analysis of discharged smokeless powder residues

A novel method for the estimation of intermediate-long firing distance range is proposed. The method is based on the characterization and chemical analysis of the smokeless powder particles on the target. An adhesive lifter is applied to collect the suspected gunshot residues (GSRs) from the surface of an object, and a Modified Griess Test (MGT) is carried out after alkaline hydrolysis on the adhesive lifter. Visualized particles are removed from the adhesive lifter under a microscope. Two systems are used for the analysis of organic discharge residues from the smokeless powder: (1) gas chromatography/thermal energy analysis (GC/TEA) for the analysis of nitroglycerine (NG) and 2,4-dinitrotoluene (2,4-DNT), (2) gas chromatography/mass spectrometry (GC/MS) for the identification of organic components such as DNT, NG, and some stabilizers. By using this procedure and confirming that the suspected particles are indeed GSR, one can estimate the intermediate-long firing distance of c. 0.75-3 m in the presence of very few particles and provide information for the classification of ammunition type in casework.     

A comparison of smokeless powders and mixtures by capillary zone electrophoresis

The analysis of inorganic ions present in smokeless and muzzleloading powders has been performed using capillary zone electrophoresis (CZE). Previous publications have examined inorganic low explosives using CZE, but have not looked at the ion profiles from smokeless powders. In this report, seven commercially available smokeless powders were analyzed as unburned powder and burned residue. The results demonstrate that ionic profiles can be used to characterize smokeless powders. Our analysis also included a smokeless powder/ Pyrodex combination to determine if smokeless powder ions are distinguishable in a mixture; however, the high concentration of ions present in Pyrodex RS prevented its detection. In addition, five different smokeless powder samples as well as Pyrodex RS were collected for analysis subsequent to deflagration in fifteen plastic pipe bombs. The relative ion concentrations between these powders can be used to illustrate the differences between open burning and pipe bomb deflagration.     

Developing a quantitative extraction technique for determining the organic additives in smokeless handgun powder.

Compositional analysis of the organic additives in smokeless handgun powder can provide forensic information to associate known and questioned samples. A reliable method for the quantitative extraction of smokeless powder additives would strengthen these measurements. To achieve quantitative recovery, both supercritical fluid extraction (SFE) and ultrasonic solvent extraction (USE) were evaluated as candidate techniques. Following a detailed evaluation of the solvent choice, the recovery of spiked additive compounds, and the effect of the powder matrix, a reliable USE technique was developed. When quantitative USE recovery of the target analytes, nitroglycerin (NG), diphenylamine (DPA), and ethyl centralite (EC), is coupled with additive measurement by micellar capillary electrophoresis (CE), compositional information can be obtained in less than 1 h.     

The traces of smokeless gunpowder

The experimental investigation resulted in detection of new specific and characteristic signs of smokeless powder. Additional tests for determination and differential diagnosis of smokeless powder variants were suggested.     

A comparison of plastic cable ties based on physical,chemical and stable isotopic measurements

Plastic cable ties can be utilised in a range of serious criminal activities and a comparison of cable ties, or fragments, may form part of the physical evidence presented to a Court of law. This research assessed the potential value of evidence based on the analysis of plastic cable ties. Twenty packets of black coloured plastic cable ties (nominally 200 mm × 4.8 mm) were purchased in pack sizes ranging from 25 to 100 individual cable ties (Brisbane, Australia, March 2015). Representative samples from each packet were visually examined, compared and tested to determine their physical dimensions, chemical compositions and stable isotopic compositions (δ²H, δ¹³C and δ¹⁵N).All of the individual cable ties from a given packet were found to be indistinguishable with respect to appearance, physical, chemical and isotopic measurements (within-batch variability). Individual cable ties were also found to be isotopically homogeneous with respect to hydrogen, carbon and nitrogen. All of the cable ties analysed were found to have very similar chemical compositions and to be manufactured predominantly from nylon 6,6. The elemental compositions of composite samples, prepared from each packet, were found to be highly variable and, as such, were of very limited value.Cable ties from ten of the twenty packets were uniquely characterised by physical appearance (between-batch variability). Physical measurements such as the width, thickness and tooth-count of the grip section did not provide additional discrimination. Cable ties from nineteen of the twenty packets were uniquely characterised by isotopic composition, based on δ²H and δ¹⁵N measurements. Samples from two packets of Crescent brand cable ties were found to be indistinguishable with respect to all of the tests applied in this study. These two packets were inadvertently purchased from the same retailer and had the same barcode and batch number. It was considered a reasonable assumption that these two packets originated from the same manufacturing batch.The authors reason that a likelihood ratio (that might be presented to a Court of law) can be derived from this type of discrete data based on a calculation of the possible combinations of distinguishable objects (unordered sampling with replacement) in a convenience sample collected from the background population. In this example, a database of 19 distinguishable objects can yield a likelihood ratio as high as 210, with a verbal equivalent of “moderately strong support” for a proposition that two cable ties have the same isotopic composition because they originate from the same batch rather than by random chance.     

Comparing the additive composition of smokeless gunpowder and its handgun-fired residues

Detecting the use of handguns via the determination of the organic additives in smokeless gunpowder residues (OGSR) presents a promising alternative to primer metal residue analysis. Compositional analysis of the gunpowder additives nitroglycerin, diphenylamine, and ethyl centralite provides information that can associate residue samples with unfired gunpowder. We evaluated the composition of seven reloading smokeless gunpowders, both in bulk and as single particles, by ultrasonic solvent extraction/capillary electrophoresis. Handgun-fired residues obtained from three common weapon calibers loaded with the known reloading powders were compared with the unfired powders. In general, the composition of the residues was similar to that found in the unfired powders. For double-base powders, comparing the ratio of the propellant (P) to the total amount of stabilizer (S) for both residue and gunpowder samples proved to be a useful measurement for identification. This P/S ratio demonstrated that the additives in the residues did not greatly change relative to the unfired powder, providing a useful indicator to aid in forensic powder and residue evaluation.     

Christianity and punitive mentalities: A qualitative study

According to David Garland (1990) scholars should be concerned about the cultural foundations of punishment in modern western society, such as religion. To this end, Garland conceptualizes punitive mentalities and sensibilities that provide the cultural support for structural systems ofpunishment. Punitive mentalities are ways of thinking about punishment, whereas punitive sensibilities are ways of feeling about punishment. Garlandsuggests that religious traditions are an important source of punitive mentalities and sensibilities. This research is an empirical analysis ofpunitive mentalities and their cultural roots, using qualitative research.Research questions focus on the following: Are there distinctively punitivementalities? How do punitive mentalities influence the desire for officialpunishment? Data from a previous study (Cook, 1998a) are analyzed here to explore terrains of punitive mentalities within the contexts of Christianity.Findings identify four distinct categories: anti-punitive, non-punitive,retributive and vengeful mentalities where Christian (non)belief systemsare important cornerstones. Respondents in each group have specific desires regarding the state's use of punishments, especially the ``death penalty''.     

A comparison of recidivism measures

Three categories-self-reported, F.B.I., and Florida Division of Corrections-of measures designed to tap recidivism are compared. When comparisons are made using different baseline measures, it is observed that variation is greatest between rather than within categories. Further, when two log-linear regressions are fitted where only the recidivism measures are different, the results are radically different. The findings demonstrate that all recidivism measures are not necessarily equally valid or reliable and that the use of different measures can produce discrepant findings.     

Support forMiranda among police chiefs: A qualitative examination

The U.S. Supreme Court recently grappled with the question of whether it should overturn the landmark case of Miranda v. Arizona. Abolitionists argued the warnings handcuffed the police and allowed many criminals to go free. Proponents maintained Miranda protected offenders and engendered a certain level of professionalism among police officers. Before the Court decided to uphold Miranda, 95 police chiefs from the Commonwealth of Virginia were surveyed about their perceptions concerning Miranda. While one could categorize many chiefs as conformists who wished to keep the warnings, a significant proportion were innovators who advocated various changes. Reasons for these beliefs and their implications are discussed.     

A qualitative examination of ethical and legal considerations regarding dating violence

Despite the increased attention to dating violence among adolescents and young adults, limited information is available on ethical and legal considerations specific to this population. Therefore, this qualitative study explores 21 trainees' and practitioners' conceptualization of ethical and legal issues pertaining to adolescent dating violence. Data are collected through focus groups included as part of an ethics and legal issues seminar. Six themes are identified to illustrate ethical and legal issues concerning dating violence: knowledge, client welfare, counseling interventions, informed consent and disclosure, barriers, and counselor reactions.     

A qualitative analysis of the use of community treatment orders in Saskatchewan

This study examined the opinions of patients who have been placed on a community treatment order (CTO), their relatives, mental health clinicians and representatives of community agencies about the use of CTOs in Saskatchewan. Patients were assessed using indepth interviews, while their relatives, mental health professionals and representatives of community agencies took part in facilitated focus groups. Patients had contradictory feelings about CTOs. Most experienced some degree of coercion while on the orders but many believed that CTOs provided necessary structure in their lives. Clinicians were more consistently positive but recognized the difficult choices in balancing the subject's right to self-determination with the benefits of a treatment order. Family members viewed CTOs as necessary to control a chaotic situation caused by the subject's limited insight.     

A qualitative study of early family histories and transitions of homeless youth

Using intensive qualitative interviews with 40 homeless youth, this study examined their early family histories for abuse, neglect, and other family problems and the number and types of transitions that youth experienced. Multiple forms of child maltreatment, family alcoholism, drug use, and criminal activity characterized early family histories of many youth. Leaving home because of either running away or being removed by child protective services often resulted in multiple transitions, which regularly included moving from foster care homes to a group home, back to their parents, and then again returning to the streets. Although having experienced family disorganization set youth on trajectories for early independence, there were many unique paths that youth traveled prior to ending up on the streets.     

A qualitative and quantitative analysis of the impact of Nebraska's decriminalization of marijuana

On January 1, 1979 Nebraska decriminalized first-offense possession of an ounce or less of marijuana. This research evaluates the impact of the new law for the purposes of (a) assessing the effectiveness of Nebraska's new law; (b) clarifying general issues regarding the decriminalization of marijuana; and (c) gaining insight into the issues surrounding the legal theory of decriminalizing a broad range of victimless crimes.     

A comparison study of hair examination methodologies

A study was conducted to investigate the accuracy between two methods of hair analysis: PCR-STR DNA analysis and microscopic comparison analysis. Standard sets of pubic hairs were collected from volunteers, and unknown sets were generated from these samples. Three out of five (60%) of the hairs analyzed produced full DNA profiles that were correctly matched to the standard sets. DNA analysis was inconclusive (partial or no DNA profile) for two out of five (40%) of the samples. In contrast, the microscopic comparison analysis correctly matched four out of five (80%) of the samples to the standard sets but mis-identified one out of five (20%) of the samples. These results reinforce the practice of preliminary microscopic hair examination in narrowing down a set of hairs for DNA analysis. Microscopic comparison analysis is sufficiently reliable to remain a rapid and inexpensive method for forensic hair analysis.     

A comparison of partner and solo arsonists

Data on 225 adult arsonists arrested in a metropolitan county over a four-year period were systematically gathered. In each case 83 variables related to the arsonist and the arson were examined. The presence or absence of a partner in crime clearly differentiated two groups of arsonists . Partner and solo arsonists are characterized by a different level of social functioning and a different burden of mental impairment and criminal history. By focusing on the partner variable, it also becomes clear that the characteristics of the offense are related to those of the offender.     

A test of sex determination from measurements of chest radiographs

Sexually dimorphic distinctions within the human thoracic area may include morphological as well as metric differences in the sternum and 4th rib. This research assesses the validity of a set of previously published measurements from chest radiographs and their use in contemporary forensic situations. The chest plates from 130 adult individuals of a known sample undergoing medico-legal post-mortem examination were examined at autopsy. Thoracic radiographs were taken using a Faxitron cabinet X-ray machine at 40 kV using Kodak Diagnostic Film Ready Pack X-Omat TL. Measurements were taken to the nearest millimetre using a sliding calliper. Logistic regression analysis of measurements of the sternum and 4th rib was undertaken to determine sex. Using 4th rib width and sternal area, sex was predicted at an accuracy of 95.8% for males and 90.3% for females.     

一种指纹快速比对的新方法

目的　提出一种大容量指纹数据的快速比对新方法。方法　采用多处理机并行比对技术 ,通过专用软件调动多处理机并行工作。结果　使指纹比对实现了快速化、准确化和性价比最优化。结论　解决了专用硬件产品价格昂贵且兼容性差、升级困难而仅靠优化比对软件算法提高速度终有极限的难题