Understanding the chemistry of the development of latent fingerprints by superglue fuming

Cyanoacrylate fuming is a widely used forensic tool for the development of latent fingerprints, however the mechanistic details of the reaction between the fingerprint residue and the cyanoacrylate vapor are not well understood. Here the polymerization of ethyl-cyanoacrylate vapor by sodium lactate or alanine solutions, two of the major components in fingerprint residue, has been examined by monitoring the time dependence of the mass uptake and resultant polymer molecular weight characteristics. This data provides insight into the molecular level actions in the efficient development of latent fingerprints by superglue fuming. The results show that the carboxylate moiety is the primary initiator of the polymerization process and that a basic environment inhibits chain termination while an acidic environment promotes it. The results also indicate that water cannot be the primary initiator in this forensic technique.     

Validating a novel tool for coding body worn camera footage of police-community member interactions

Objectives

This study aimed to validate a tool for coding police body-worn camera (BWC) footage to measure the dynamics of police–community encounters, including items related to community members, officer performance, and situational outcomes.

Methods

Over 1000 BWC videos were scored by five coders who participated in an iterative interrater reliability exercise to improve the agreement. Krippendorf's alphas and a multilevel simultaneous component analysis were used to assess interrater reliability and the component structure of ratings, respectively. Bootstrapped and multilevel exploratory and confirmatory factor analyses were conducted to ascertain any underlying dimensions supporting officer and community member behavior, and cluster analyses were performed to examine whether interactions could be grouped into coherent categories.

Results

The lower bound of unweighted means of bootstrapped alphas ranged from 0.67 to 0.96 depending upon item type, and 21.60% of the total variance in raters was between-subjects. Factor analyses revealed only a single factor (“defensiveness”) underlying four items related to hostility directed toward officers by community members. Cluster analyses described seven categories that were highly overlapping but conceptually plausible with cluster silhouette means ranging from −0.06 to 0.13.

Conclusions

We validated a collection of interval-level coding metrics on a random sample of over 1000 interactions between police officers and community members recorded through BWCs. In doing so, we provide a roadmap for researchers and practitioners to effectively measure the dynamics of police–community encounters and officer performance within those encounters and a framework for addressing the validity and reliability of items in future studies involving the measurement of BWC footage.     

The Frequency of Excess Auto Personal Injury Claims

This study analyzes auto personal injury claims across the statesto estimate the frequency of claims for nonexistent or preexistinginjuries. We develop a series of hypotheses regarding the specificclaiming patterns that would signal the presence of excess claims.We draw on a nationally representative sample of auto-accidentinjury claims closed during 1987 to test these hypotheses. Theresults strongly support the hypotheses. We conclude that approximately42% of reported soft-injury claims in the dollar-threshold andtort states are for nonexistent or preexisting injuries.     

Exploring the Impact of Child Sex Offender Suicide

This paper explores the issues and widespread impact surrounding child sex offenders (CSO) who commit suicide after learning they are under criminal investigation. This phenomenon, which has received scant attention in the literature, affects family, friends, and victims of offenders who may experience a range of conflicting emotions including anger, guilt, confusion, betrayal, and loss. Involved law enforcement may, likewise, experience a range of complex reactions. Law enforcement personnel are neither trained nor required to assess offenders’ suicidality. However, awareness of how CSOs are impacted by an investigation may mitigate the risk of suicide and enhance operational strategies, including officer safety.     

Incentives, criminal defence lawyers and plea bargaining

Plea bargaining has become a central feature of criminal procedure in Anglo-Saxon jurisdictions. This paper explores an area seldom discussed in the economic literature on plea bargaining: the influence of the defence lawyer's fee contract on the terms of the bargain. In particular, it uses data from one jurisdiction of the impact on case trajectories of changes in publicly funded defence lawyers’ contracts to test the proposition that the nature of the lawyer's contract influences how cases are managed. An event study methodology on a pooled time-series cross-section data set of case trajectories before and after the change in the nature of the contract is used to examine whether the new payment regime significantly changed the trajectories of cases through the summary criminal justice system. Overall the results seem to suggest that the behaviour of defence lawyers may be influenced by financial incentives. This implies that the terms of plea bargains reached between prosecution and defence lawyers may be affected by the defence lawyer's remuneration contract. Consequently, the authors conclude that the role of defence lawyers has been under-researched in the literature on the economics of plea bargaining.