The detection of multiply charged dyes using matrix-assisted laser desorption/ionization mass spectrometry for the forensic examination of pen ink dyes directly from paper

Abstract:  Laser desorption mass spectrometry (LDMS) is emerging as a technique for questioned document examination. Its use is limited to detecting ink dyes that are neutral or singly charged. Several inks contain dyes that are multiply charged and LDMS cannot be employed for their identification. We have successfully detected >20 polyionic dyes that can be used in the manufacture of inks using matrix-assisted laser desorption/ionization (MALDI) MS, directly from paper, with the matrix, 2-(4-hydroxyphenylazo)benzoic acid (HABA), and the additive, diammonium hydrogen citrate (DAHC). For example, Acid Violet 49, a charged dye containing one positively-charged site and two negatively charged sulfonate groups, cannot be detected by LDMS, but forms intact, singly charged ions in the MALDI MS experiment. The method described is also useful for identifying multiply charged dye mixtures that are used in modern pen inks.     

Youth Psychopathy and Criminal Recidivism: A Meta-Analysis of the Psychopathy Checklist Measures

Although narrative reviews have suggested that "youth psychopathy" is a strong predictor of future crime and violence, to date no quantitative summaries of this literature have been conducted. We meta-analyzed recidivism data for the Psychopathy Checklist measures across 21 non-overlapping samples of male and female juvenile offenders. After removing outliers, psychopathy was significantly associated with general and violent recidivism (r (w)'s of .24 and .25, respectively), but negligibly related to sexual recidivism in the few studies examining this low base rate outcome. Even after eliminating outliers, however, considerable heterogeneity was noted among the effects, with some of this variability being explained by the gender and ethnic composition of the samples. Effect sizes for the small number of female samples available for analysis were mostly small and nonsignificant, and psychopathy was a weaker predictor of violent recidivism among more ethnically heterogeneous samples. In relation to predicting both general and violent recidivism, psychopathy performed comparably to an instrument designed specifically to assess risk, the Youth Level of Service/Case Management Inventory (Hoge & Andrews, 2002).     

Analysis of Pigmented Inkjet Printer Inks and Printed Documents by Laser Desorption/Mass Spectrometry*,†

Abstract: Anyone with a computer, scanner, and color printer has the capability for creating documents such as identification cards, passports, and counterfeit currency. Laser desorption mass spectrometry (LDMS) has been demonstrated as a powerful tool for colorant analysis. Inkjet printers are now moving largely toward the use of pigments as colorants; their insolubility makes analysis by simpler methods such as thin‐layer chromatography no longer an option. Recent developments in pigmented inkjet printer inks, such as gloss optimizers that coat pigment particles, may prohibit colorant analysis by LDMS. We demonstrate here that pigments used in inks from two Epson printers can be detected and analyzed by LDMS. Also, LDMS spectra of various colors created using a 4‐cartridge (cyan/magenta/yellow/black, CMYK) inkset are evaluated, to begin to develop an approach for unraveling LDMS data from real samples, to determine the number of inks used by a printer, and the chemical composition of the colorants.     

The Differentiation of the Volatile Organic Signatures of Individuals Through SPME-GC/MS of Characteristic Human Scent Compounds

Abstract:  Human scent evidence is utilized as an investigative tool through canine scent discriminations based on the premise that human scent is an individualizing characteristic. This study describes the development of what is effectively a human scent barcode consisting of the relative ratios of an individual's "primary odor" compounds utilized to determine a reproducible and individualizing profile which can be stored in a searchable database for a proof of concept of human scent as a biometric measure. Triplicate hand odor samples were evaluated from 10 subjects utilizing solid phase micro-extraction gas chromatography/mass spectrometry (SPME-GC/MS) and compared via Spearman Rank Correlations. Narrowing the compounds considered for each subject to only those common in all three samples, or a subject's "primary odor constituents," produced a greater degree of both individualization and discrimination; at both correlation thresholds of 0.9 and 0.8, the individuals were correctly discriminated and identified in 99.54% of the cases.     

Police-Induced Confessions,Risk Factors,and Recommendations: Looking Ahead

Reviewing the literature on police-induced confessions, we identified suspect characteristics and interrogation tactics that influence confessions and their effects on juries. We concluded with a call for the mandatory electronic recording of interrogations and a consideration of other possible reforms. The preceding commentaries make important substantive points that can lead us forward—on the effects of videotaping of interrogations on case dispositions; on the study of non-custodial methods, such as the controversial Mr. Big technique; and on an analysis of why confessions, once withdrawn, elicit such intractable responses compared to statements given by child and adult victims. Toward these ends, we hope that this issue provides a platform for future research aimed at improving the diagnostic value of confession evidence.     

Enrollment in Mental Health Courts: Voluntariness,Knowingness, and Adjudicative Competence

Mental health courts (MHCs) are rapidly expanding as a form of diversion from jails and prisons for persons with mental illness charged with crimes. Although intended to be voluntary, little is known about this aspect of the courts. We examined perceptions of voluntariness, and levels of knowingness and legal competence among 200 newly enrolled clients of MHCs at two courts. Although most clients claimed to have chosen to enroll, at the same time, most claimed not to have been told the court was voluntary or told of the requirements prior to entering. The majority knew the “basics” of the courts, but fewer knew more nuanced information. A minority also were found to have impairments in legal competence. Implications are discussed.     

Birds of a Feather Fight Together: Status-Enhancing Violence,Social Distance and the Emergence of Homogenous Gangs

Objectives

This study proposes a theoretical framework for understanding two empirical findings from gang research: (1) gangs are generally racially homogenous, even in heterogeneous environments, and (2) gang violence tends to be intra-racial. We draw from the extensive literature on street gangs as well as from research on group formation and status-enhancing behavior to develop a theoretical model of gang formation.

Methods

Using game theory, we model the simultaneous decisions of individuals to commit status-enhancing acts of violence and to seek protection by joining a gang. We then conduct computer simulations to examine the resulting patterns of violence and gang composition.

Results

We demonstrate that as long as some social distance exists between racial groups in a community, gang violence will be intra-racial and gangs will be homogenous. We find that our results are robust to a number of simple variations of the model and allow us to generate several hypotheses about the nature of gang formation and patterns of violence.

Conclusions

When violence is motivated by socially constructed rewards, socially closer targets are likely to yield greater rewards. In such a system, individuals must reduce their likelihood of victimization by entering a social contract of non-violence (i.e. gang membership) with individuals who might view them as status-enhancing targets (i.e. socially close individuals). The result is that gangs are made up of socially close individuals interested in attacking other socially close individuals. Therefore, gangs tend to be racially homogenous and violence is overwhelmingly intra-racial.

     

What do students really know about criminal justice?

This survey of three hundred and twenty undergraduate students attempted to determine their knowledge of crime and punishment in North Carolina. Respondents answered a series of open- and closed-ended questions regarding various legal topics, such as statutory rape and the legal ages for tobacco and alcohol use. The participants were also asked to list punishments for various offenses, such as possession of marijuana, driving while intoxicated, and rape. They were then asked to define certain legal terms such as larceny. The results indicated that most students were unable to provide correct corresponding punishments for many offenses. They were also unable to accurately define various legal terms, such as robbery or rape. The implications for stronger education in the area of criminal justice are discussed.     

The Balance of Power in Rural Marketing Networks: A Case Study of Snake Trading in Cambodia

Producers in small-scale rural markets often receive unfavourable prices for their goods as a result of more powerful market participants. This study uses a combination of price analysis and interview data to assess the position of snake hunters in the aquatic snake market from Tonle Sap Lake in Cambodia. Despite the hunters' dependence on intermediary traders for market access and credit, the evidence implies that they are not powerless participants. Intermediary traders operate under high competition as a result of the increasing scarcity of snakes and therefore, despite interlocked credit and snake markets, offer relatively high prices to hunters.     

Raman Spectroscopy as a Simple,Rapid, Nondestructive Screening Test for Methamphetamine in Clandestine Laboratory Liquids

Raman spectroscopy has found increased use in the forensic controlled substances laboratory in recent years due to its rapid and nondestructive analysis capabilities. Here, Raman spectroscopy as a screening test for methamphetamine in clandestine laboratory liquid samples is discussed as a way to improve the efficiency of a laboratory by identifying the most probative samples for further workup among multiple samples submitted for analysis. Solutions of methamphetamine in ethanol, diethyl ether, and Coleman fuel were prepared in concentrations ranging from 0.5% to 10% w/v, and Raman spectra of each were collected. A concentration‐dependant Raman peak was observed at 1003 per cm in each solution in 4% w/v and greater solutions. Case samples were analyzed and also found to reliably contain this diagnostic peak when methamphetamine was present. The use of this diagnostic indicator can save the forensic controlled substances laboratory time and materials when analyzing clandestine laboratory liquid submissions.