Bounding the number of contributors to mixed DNA stains

We derive a simple inequality for the probability of observing a given DNA profile when assuming a fixed number of unknown persons have contributed to the mixed stain. We then show how this inequality can be used to obtain an upper bound for the number of unknown contributors needed to be considered.     

行政立法程序的民主与效率

行政立法程序既应追求行政行为的效率,又应追求立法行为的民主。在民主与效率之间,行政立法程序应以民主为更高的价值追求。针对我国目前的法律、法规及行政立法的现状,在行政立法准备制定阶段应建立更为民主的制度,但同时也不能忽略行政立法程序的效率。     

Restoring accountability in pretrial release: the Philadelphia pretrial release supervision experiments

As drug arrests and jail overcrowding added pressure to increase pretrial release in localities during the 1980s and 1990s, the need to manage a larger and higher-risk pretrial population of defendants awaiting adjudication in the community became a high priority for justice agencies. In the late 1990s Philadelphia officials sought to discover the ingredients of a successful supervision strategy through four interlinked field experiments to provide an empirical basis for a major reform of the pretrial release system. The results of the linked randomized experiments question common assumptions about “supervision,” its impact and effectiveness, about the underlying nature of the noncompliant defendant, and deterrence implications. The study emphasizes the importance of interpreting the findings in the context of implementation of the policy reform. Findings suggest that facilitative notification strategies wield little influence on defendant behavior and that deterrent aims are undermined by the system's failure to deliver consequences for defendant noncompliance during pretrial release. The most significant contribution of the article is its illustration of a major evidence-based policy reform undertaken by a major court system.     

Assessing Market Power: The Trade-off Between Market Concentration and Multi-Market Participation

This analysis reveals that traditional market power measuresare biased under the conditions of multi-market participationand demand interdependence. Specifically, when complementary(substitutable) demands dominate, traditional market power measuresare biased upward (downward). A similar bias carries over tothe evaluation of mergers. To wit, mergers that simultaneouslyincrease market concentration and multi-market participationcan result in lower prices even in the absence of merger economies.It follows that merger guidelines that place undue emphasison market concentration can lead policymakers to block (approve)mergers that enhance (diminish) consumer welfare.     

Proficiency testing (external quality assessment) of drug detection in oral fluid

Eighteen external quality assessment (proficiency testing) samples were prepared from client specimens collected with the Intercept^® oral fluid collection device and by spiking drug-free oral fluid. Samples were circulated in pairs at quarterly intervals to 13 UK and USA based laboratories for analysis by a panel of OraSure micro-plate Intercept^® enzyme immunoassay kits and hyphenated mass spectrophotometric techniques. During the survey, there was a single case of non-specificity in a false report for methadone. The major errors were of lack of sensitivity relative to the concentration thresholds specified for the immunoassays. The sensitivity for overall ‘present’/‘not found’ reports calculated as true positives/(true positives + false negatives) were for the amfetamine specific assay 50%, methyl-amfetamines 93%, barbiturates 64%, cannabinoids 73%, cocaine and metabolites 100%, benzodiazepines 69%, methadone 95%, opiates 79% (opiates excluding oxycodone 93%), phencyclidine 93% and human gamma-globulin 97%. A small number of the sensitivity errors were attributable to errors in chromatographic confirmation techniques.     

The effect of authority and social influence on eyewitness suggestibility and person recognition

This study investigated the influence of an authority figure on eyewitness identification. Participants watched a staged crime and then were administered a photo lineup by either an authority (policeman) or non-authority figure (civilian). Participants in the authority condition were more likely to choose a lineup member than those in the non-authority condition. There was no effect of authority, however, on the accuracy of the identification decisions. The lack of a deleterious effect suggests that the presence of a police officer during identification procedures does not create an unduly suggestive situation or have undesirable effects on eyewitness identification decisions. Although witnesses' choosing behaviors did not increase the rate of identification errors, the effect of the administrator's authority on choosing was reduced when unbiased instructions (vs. biased instructions) were presented to the witnesses. Thus, support was found for the use of neutral instructions during eyewitness identification procedures.