Detecting Specialization in Offending: Comparing Analytic Approaches

Offending specialization continues to be a subject of empirical inquiry for scholars interested in criminal careers. Early research consistently spoke to the generality of offending profiles, but more recent work has revealed somewhat mixed findings. These results have emerged alongside newly developed and applied methods that detect and describe offending specialization. To what extent these methods shape divergent conclusions and/or provide overlapping insight remains unclear, however. Therefore, the degree to which more recent inquiries are actually studying the same operational definition of specialization is unknown. In order to consider this issue further, this study utilizes four frequently applied approaches with a single data set. The study indicates when and where findings converge and also describes any unique insights provided by each method. The work concludes with a discussion surrounding the utility of applying multiple strategies in assessing specialization in criminal offending.     

Forensic analysis of explosives using isotope ratio mass spectrometry (IRMS) — Preliminary study on TATP and PETN

The application of isotopic techniques to investigations requiring the provision of evidence to a Court is limited. The objective of this research was to investigate the application of light stable isotopes and isotope ratio mass spectrometry (IRMS) to solve complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques.Due to the current threat of organic peroxide explosives, such as triacetone triperoxide (TATP), research was undertaken to determine the potential of IRMS to differentiate samples of TATP that had been manufactured utilising different starting materials and/or manufacturing processes. In addition, due to the prevalence of pentaerythritoltetranitrate (PETN) in detonators, detonating cord, and boosters, the potential of the IRMS technique to differentiate PETN samples from different sources was also investigated.Carbon isotope values were measured in fourteen TATP samples, with three definite groups appearing in the initial sample set based on the carbon data alone. Four additional TATP samples (in a second set of samples) were distinguishable utilising the carbon and hydrogen isotopic compositions individually, and also in combination with the oxygen isotope values. The 3D plot of the carbon, oxygen and hydrogen data demonstrated the clear discrimination of the four samples of TATP. The carbon and nitrogen isotope values measured from fifteen PETN samples, allowed samples from different sources to be readily discriminated.This paper demonstrates the successful application of IRMS to the analysis of explosives of forensic interest to assist in discriminating samples from different sources. This research represents a preliminary evaluation of the IRMS technique for the measurement of stable isotope values in TATP and PETN samples, and supports the dedication of resources for a full evaluation of this application in order to achieve Court reportable IRMS results.     

Forensic analysis of explosives using isotope ratio mass spectrometry (IRMS) — Discrimination of ammonium nitrate sources

An evaluation was undertaken to determine if isotope ratio mass spectrometry (IRMS) could assist in the investigation of complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques. The focus of the research was on ammonium nitrate (AN), a common oxidiser used in improvised explosive mixtures.The potential value of IRMS to attribute Australian AN samples to the manufacturing source was demonstrated through the development of a preliminary AN classification scheme based on nitrogen isotopes. Although the discrimination utilising nitrogen isotopes alone was limited and only relevant to samples from the three Australian manufacturers during the evaluated time period, the classification scheme has potential as an investigative aid.Combining oxygen and hydrogen stable isotope values permitted the differentiation of AN prills from three different Australian manufacturers. Samples from five different overseas sources could be differentiated utilising a combination of the nitrogen, oxygen and hydrogen isotope values. Limited differentiation between Australian and overseas prills was achieved for the samples analysed.The comparison of nitrogen isotope values from intact AN prill samples with those from post-blast AN prill residues highlighted that the nitrogen isotopic composition of the prills was not maintained post-blast; hence, limiting the technique to analysis of un-reacted explosive material.     

Developmental validation of a Cannabis sativa STR multiplex system for forensic analysis

A developmental validation study based on recommendations of the Scientific Working Group on DNA Analysis Methods (SWGDAM) was conducted on a multiplex system of 10 Cannabis sativa short tandem repeat loci. Amplification of the loci in four multiplex reactions was tested across DNA from dried root, stem, and leaf sources, and DNA from fresh, frozen, and dried leaf tissue with a template DNA range of 10.0-0.01 ng. The loci were amplified and scored consistently for all DNA sources when DNA template was in the range of 10.0-1.0 ng. Some allelic dropout and PCR failure occurred in reactions with lower template DNA amounts. Overall, amplification was best using 10.0 ng of template DNA from dried leaf tissue indicating that this is the optimal source material. Cross species amplification was observed in Humulus lupulus for three loci but there was no allelic overlap. This is the first study following SWGDAM validation guidelines to validate short tandem repeat markers for forensic use in plants.     

Judgments of culpability in a filicide scenario

Previous research has indicated that potential jurors are likely to use personal biases, such as those based on gender and ethnicity, in their judgments of culpability of criminal defendants in addition to, or instead of, the facts of the crime. The present paper seeks to extend this literature to the crime of filicide; to examine whether male defendants are judged more harshly than female defendants, as is the case for domestic violence and sexual abuse. 214 participants were provided with a scenario of filicide in which the gender of the perpetrator, the gender of the child, and the family's social class were randomly assigned. Participants were asked to rate the culpability of the defendant in the case. Results indicated that, unlike for other violent crimes, participants did not use gender or social class biases in their judgments of criminal culpability.     

Anger disturbances among perpetrators of intimate partner violence: clinical characteristics and outcomes of court-mandated treatment

In the present study, the authors clustered a pretreatment sample of 190 perpetrators of intimate partner violence (IPV) mandated to attend group counseling based on State-Trait Anger Expression Inventory scores and examined whether these profiles were associated with differential outcomes 1 year postadjudication. Cluster analysis revealed 3 groups: (a) high anger-expressive (HA-E, n = 56), (b) moderate anger-inexpressive (MA-IE; n = 13), and (c) low anger (LA; n = 118). HA-E men perpetrated more IPV, reported experiencing and witnessing more abuse during childhood, scored higher on psychopathology measures, and reported more substance problems. HA-E and MA-IE males had higher program attrition and rearrest rates; MA-IE males were more likely to be arrested for assault-related offenses. Thus, although the majority of partner-abusive men do not present with anger-related disturbances, the presence of anger problems may be a marker for an array of traits that may complicate the treatment process.     

Targeted Neighborhood Sampling: A New Approach for Recruiting Abusive Couples

We conducted two studies to test the utility of a new strategy for recruiting couples experiencing intimate partner violence. This new strategy, Targeted Neighborhood Sampling, involves utilizing police reports of family fight calls to target particular areas within a city for recruitment efforts. Study I compared the efficacy of using this method to recruit a random versus a convenience sample. Results demonstrated that Targeted Neighborhood Sampling was most effective when recruiting a convenience sample of participants who responded to flyers left at their residences. Study II used a convenience sample and replicated the findings from Study I. Across the two studies, 40.4% of those who called after receiving a flyer experienced male-to-female partner violence within the past year. In addition, we combined data across studies and correlated types of violence the couples experienced with variables commonly associated with abuse. Psychological aggression, physical assault, and injury were all positively associated with reports of demand-withdrawal and mutual avoidance during conflict, as well as depression and symptoms of post traumatic disorder syndrome. Sexual coercion was associated with drug abuse. These results demonstrate the utility and validity of Targeted Neighborhood Sampling.

Adolescent Self-Esteem and Gender: Exploring Relations to Sexual Harassment, Body Image, Media Influence, and Emotional Expression

Self-esteem plays a central role in mental health, yet not enough is known about how youth evaluate themselves as they move across adolescence. This study used a cross-sectional design to examine age and gender patterns in self-esteem and to explore how contemporary social influences relate to adolescent self-esteem. Self-reported influences on self-esteem involving the media, sexual harassment, body image, family and peer relationships, and emotional expression were evaluated with 93 boys and 116 girls in Grades 5, 8, and 12. Girls reported lower self-esteem than boys in early adolescence, and late adolescent boys reported lower self-esteem than younger boys. The predictors as a set accounted for a significant portion of the variance in self-esteem, while the best predictor of self-esteem varied by age and gender. Large gender differences were present for emotional expression, with boys becoming more restrictive across adolescence. Girls reported more negative body image and media influence scores than did boys in late childhood and early adolescence. Body image appeared to mediate the relationships between certain predictors and self-esteem for girls, while gender and grade appeared to moderate the relationship between media influence and self-esteem for girls and boys.     

The Impact of the 1994 Federal Assault Weapon Ban on Gun Violence Outcomes: An Assessment of Multiple Outcome Measures and Some Lessons for Policy Evaluation

The Federal Violent Crime Control and Law Enforcement Act of 1994 bans a group of military-style semiautomatic firearms (i.e., assault weapons) and ammunition magazines capable of holding more than 10 rounds. Ban advocates argue that these weapons are particularly dangerous because they facilitate the rapid firing of high numbers of shots. Though the banned guns and magazines were used in only a modest fraction of gun crimes before the law, it was hypothesized that a decrease in their use might reduce gunshot victimizations, particularly those involving multiple wounds and/or victims. In response to a Congressional mandate for an impact assessment of the law, this study utilized national and local data sources and a variety of analytical techniques to examine the ban's short-term impact on gun violence. The ban may have contributed to a reduction in gun homicides, but a statistical power analysis of our model indicated that any likely impact from the ban will be very difficult to detect statistically for several more years. We found no evidence of reductions in multiple-victim gun homicides or multiple-gunshot wound victimizations. The findings should be treated cautiously due to the methodological difficulties of making a short-term assessment of the ban and because the ban's long-term effects could differ from the short-term impacts revealed by this study.