Morphology of low-velocity impact stains produced from single drops of blood

Systematic variation of blood droplet volume, the distance fallen and the surface (paper, wood, plastics, tiles) led to the conclusion that the size and the shape of the stains ("fingers", satellites) allowed to deduce the distance fallen but only if the actual surface structure was known. We found that detailed photography at the crime scene was necessary, yet experiments have to be performed due to the extreme influence of the actual surface texture on all characteristics (size, spines, peripheral spatter) of the blood stains.     

Population data of 10 Y-chromosomal STR Loci in Cebu province, Central Visayas (Philippines)

Population: 103 unrelated male individuals from Cebu province, Central Visayas region of the Philippines.     

Challenging the ‘invariance’ thesis: procedural justice policing and the moderating influence of trust on citizens’ obligation to obey police

Objectives

This paper examines the effects of a procedural justice policing intervention on citizens’ feelings of obligation to obey police. It examines whether the efficacy of procedural justice on citizens’ obligation to obey police may be contingent on citizens’ level of trust in police during a police–citizen encounter.

Methods

This research draws on survey data from the Queensland Community Engagement Trial (QCET). QCET was a randomized controlled field trial implemented by the Queensland Police Service. The trial exposed citizens to either a procedural justice experience (experimental condition) or standard police practice (control condition) during a random roadside stop. Survey responses were received from 1107 drivers in the experimental condition and 1655 drivers in the control condition.

Results

Compared to the control condition, the procedural justice condition yielded higher levels of trust in the police officer conducting the roadside stop. No differences in obligation to obey police were observed between the two conditions. Importantly, citizens’ level of trust in the officer moderated the effect of the intervention on obligation to obey police. Specifically, the procedural justice condition had a negative effect on obligation to obey for those reporting low trust in police. For those high in trust, the procedural justice intervention had a slight but insignificant positive effect on obligation to obey.

Conclusions

The findings suggest that procedural justice effects can vary between individuals; specifically, the findings reveal that procedural justice interventions can sometimes be counter-productive, depending on the level of trust a citizen exhibits toward police during an encounter. Police agencies should therefore be aware of potential counter-productive effects when implementing procedural justice in the field.

     

The application of ultraviolet irradiation to exogenous sources of DNA in plasticware and water for the amplification of low copy number DNA

Using high sensitivity forensic STR polymerase chain reaction (PCR) typing procedures, we have found low concentrations of DNA contamination in plasticware and water assumed to be sterile, which is not detected by standard DNA procedures. One technique commonly used to eliminate the presence of DNA is ultraviolet (UV) irradiation; we optimized such a protocol used in the treatment of water, tubes, plates, and tips for low copy number DNA (LCN) amplification. UV light from a Stratalinker((R)) 2400 was administered to 0.2, 1.5 mL tubes, and PCR plates contaminated with up to 500 pg of DNA. They were subsequently quantified with an ALU-based real-time PCR method using the Rotorgene 3000. Overall, there was a decrease in concentration of DNA recovered as the duration of treatment increased. Nonetheless, following 45 min of irradiating a PCR plate with 500 pg of DNA, nearly 6 pg were still detected. However, when the plate was raised within an inch of the UV source, less than 0.2 pg of DNA was detected. Additionally, lining the area around the samples with aluminum foil further reduced the amount of time necessary for irradiation, as only 30 min eliminated the presence DNA in the raised PCR plate. Similar experiments were conducted using tubes filled with a solution of DNA and water in equivalent concentrations for 50, 15, and 1.5 mL tubes with comparative results. It is plausible that the aluminum foil increased the amount of reflection in the area thereby enhancing penetration of UV rays through the walls of the plasticware. This protocol was tested for the possibility of inhibitors produced from irradiation of plastic tubes. As our protocols require less irradiation time than previous studies, PCR sensitivity was not affected. Moreover, the lifespan of the UV lamps was extended. Our findings demonstrate that this method is useful as an additional precautionary measure to prevent amplification of extraneous DNA from plasticware and water without compromising the sensitivity of LCN DNA amplifications.     

Psychopathology in women arrested for domestic violence

This study examined the prevalence of psychopathology among women arrested for violence and whether the experience of intimate partner violence (IPV) was associated with Axis I psychopathology. Women who were arrested for domestic violence perpetration and court referred to violence intervention programs (N= 103) completed measures of IPV victimization, perpetration, and psychopathology. Results revealed high rates of posttraumatic stress disorder (PTSD), depression, generalized anxiety disorder (GAD), panic disorder, substance use disorders, borderline personality disorder, and antisocial personality disorder. Violence victimization was significantly associated with symptoms of psychopathology. Logistic regression analyses showed that sexual and psychological abuse by partners were associated with the presence of PTSD, depression, and GAD diagnoses. Results highlight the potential importance of the role of violence victimization in psychopathology. Results suggest that Axis I and Axis II psychopathology should routinely be assessed as part of violence intervention programs for women and that intervention programs could be improved by offering adjunct or integrated mental health treatment.     

Development of a pentaplex X-chromosomal short tandem repeat typing system and population genetic studies

Quadruplex and pentaplex systems for polymerase chain reaction amplification of X-chromosomal short tandem repeats DXS101, HPRTB, DXS8377, DXS981 (STRX1) and DXS6789 were developed for automated profiling of liquid and membrane-bound DNA samples. Chinese, Japanese and Thai populations were typed using a quadruplex system, while German and Philippine populations were analyzed using a five-locus system. Out of 88 meioses studied in Philippine family samples at each locus, a possible one repeat deletion (allele 51 to 50) at DXS8377 was observed in a father-daughter pair. Exact tests performed on genotype data from females in the Philippine, German and Thai populations indicated that these groups conform to Hardy-Weinberg equilibrium. Exact tests for population differentiation indicate significant variations in allele distributions, particularly at loci DXS101, DXS981 and DXS6789. Considered individually, DXS8377 was the most polymorphic and HPRTB the least polymorphic locus in these five populations. When the forensic efficiency of the quadruplex system was calculated, the combined power of discrimination among males (PD(M)) was no lower than 0.998, while among females the combined PD(F) was at least 0.9999 in all populations. The combined power of paternity exclusion was a minimum of 0.998 in trio cases and 0.98 in motherless cases. The addition of locus DXS6789 to the German and Philippine population databases using a pentaplex increased the forensic efficiency of the analysis system.     

Parent–Child Discordance and Child Trauma Symptomatology Throughout Therapy: Correlates and Treatment Response

Children and their caregivers often disagree when reporting on child behavioural and emotional difficulties. But how does parent–child discordance relate to outcomes, particularly among children undergoing trauma therapy? This study examined parent–child discordance in relation to children’s trauma symptoms and therapy outcomes. Participants included 96 trauma-exposed children and their caregivers, who received Trauma-Focused Cognitive Behavioural Therapy. Discordance was calculated using absolute difference scores between child- and parent- reported psychological symptoms. Parent–child discordance, calculated at pre-therapy, post-therapy, and at a six-month follow-up, predicted the severity of children’s posttraumatic stress, dissociation, and internalizing and externalizing difficulties at each respective time-point. Pre-therapy discordance predicted improvements in externalizing behaviours after therapy and at follow-up. Improvements in discordance predicted improvements in trauma-specific symptoms over the course of treatment and at follow-up. The findings underscore how changes in parent–child discordance are related to child trauma symptoms and treatment response. Clinical implications and future directions are discussed.