Proper assessment of the JFK assassination bullet lead evidence from metallurgical and statistical perspectives

The bullet evidence in the JFK assassination investigation was reexamined from metallurgical and statistical standpoints. The questioned specimens are comprised of soft lead, possibly from full-metal-jacketed Mannlicher-Carcano (MC), 6.5-mm ammunition. During lead refining, contaminant elements are removed to specified levels for a desired alloy or composition. Microsegregation of trace and minor elements during lead casting and processing can account for the experimental variabilities measured in various evidentiary and comparison samples by laboratory analysts. Thus, elevated concentrations of antimony and copper at crystallographic grain boundaries, the widely varying sizes of grains in MC bullet lead, and the 5-60 mg bullet samples analyzed for assassination intelligence effectively resulted in operational sampling error for the analyses. This deficiency was not considered in the original data interpretation and resulted in an invalid conclusion in favor of the single-bullet theory of the assassination. Alternate statistical calculations, based on the historic analytical data, incorporating weighted averaging and propagation of experimental uncertainties also considerably weaken support for the single-bullet theory. In effect, this assessment of the material composition of the lead specimens from the assassination concludes that the extant evidence is consistent with any number between two and five rounds fired in Dealey Plaza during the shooting.     

The application of pancuronium bromide (Pavulon) forensic analyses to tissue samples from an "Angel of Death" investigation

The case report of a serial killer who worked at several hospitals as a respiratory therapist is presented. The suspect was initially labeled a benevolent Angel of Death who ended the suffering of elderly patients through mercy killing. However, his subsequently declared motive for homicide was very different from other similar cases in medical settings. The application of new analysis techniques for the detection of pancuronium bromide in a series of aged exhumation tissues gave positive results and led to the resultant conviction of the therapist.     

Comparing Effect Sizes in Follow-Up Studies: ROC Area,Cohen's <Emphasis Type="Italic">d</Emphasis>, and <Emphasis Type="Italic">r</Emphasis>

In order to facilitate comparisons across follow-up studies that have used different measures of effect size, we provide a table of effect size equivalencies for the three most common measures: ROC area (AUC), Cohen's d, and r. We outline why AUC is the preferred measure of predictive or diagnostic accuracy in forensic psychology or psychiatry, and we urge researchers and practitioners to use numbers rather than verbal labels to characterize effect sizes. Strictly speaking, d values pertain only to variables scored on an interval scale. When the nondichotomous variable is ordinally scaled, r or AUC should be used. Nevertheless, the values in Table 1 allow one to compare the relative magnitudes across studies that have reported any of the three effect size measures.     

Evaluation of an objective assessment technique for the detection of malingered memory deficits

Clinicians generally operate under the implicit assumption that their clients are being honest and putting forth their best effort on assessment procedures. However, clients may realize substantial secondary gains by appearing impaired. The present study evaluates an objective assessment procedure for the detection of malingered memory deficits. Results demonstrate that college students instructed to malinger memory impairment show different patterns of responding and can be clearly differentiated from students performing their best and from actual memory-impaired patients. Applying one of two scores derived from this test to a sample of 20 students instructed to malinger, 20 control subjects, and 20 memory impaired subjects performing their best resulted in a 100% hit rate for normal controls and memory-impaired subjects, and a 65% hit rate for experimental malingerers.This study was presented in a somewhat different form at the 10th Annual Conference of the National Academy of Neuropsychology; November, 1990; Reno. The test evaluated in this study is available to researchers upon request to the second author.     

Entrapment and the entrapment defense: Dilemmas for a democratic society

Entrapment is defined and distinguished from related law enforcement practices. The subjective test of entrapment formulated by the Supreme Court and the objective test proposed by critics are discussed and evaluated. The argument is advanced that entrapment is a morally unjustifiable practice which is inconsistent with the rights of citizens in a democratic society. Guidelines are proposed for governing police conduct in potential entrapment situations and suggestions made regarding ways these guidelines might be implemented.The authors wish to thank the following individuals for helpful comments on an earlier draft of this paper: Joseph A. Canale; Edward W. Chandler; Gary T. Marx; and Eugene L. Shapiro.     

How do different sources of policy analysis affect policy preferences? Experimental evidence from the United States

Policy Sciences - Analysis of policy options is often unavailable or only available from non-governmental research organizations (“think tanks”) that may have explicit or implicit...     

Can circles of support and accountability (CoSA) significantly reduce sexual recidivism? Results from a randomized controlled trial in Minnesota

Objectives

This study evaluates the effectiveness of Minnesota Circles of Support and Accountability (MnCOSA), a sex offender reentry program implemented by the Minnesota Department of Corrections in 2008.

Methods

Using a randomized controlled trial, this study compares recidivism and cost–benefit outcomes among sex offenders in the MnCOSA (N?=?50) and control groups (N?=?50).

Results

The results suggest MnCOSA significantly reduced sexual recidivism, lowering the risk of rearrest for a new sex offense by 88%. In addition, MnCOSA significantly decreased all four measures of general recidivism, with reductions ranging in size from 49 to 57%. As a result of the reduction in recidivism, findings from the cost–benefit analysis reveal the program has generated an estimated $2 million in costs avoided to the state, resulting in a benefit of $40,923 per participant. For every dollar spent on MnCOSA, the program has yielded an estimated benefit of $3.73.

Conclusions

Although difficult to implement, the CoSA model is a cost-effective intervention for sex offenders that could also be applied to other correctional populations with a high risk of violent recidivism.