Improved Area of Origin Estimation for Bloodstain Pattern Analysis Using 3D Scanning

An important component of crime scene reconstruction is bloodstain pattern analysis (BPA). Where BPA concerns impact patterns, estimating the area of origin is critical information for scene reconstruction. Traditionally, this is achieved by measuring individual bloodstains and performing trigonometric calculations; however, 3D scanning has been proposed as a viable alternative for overcoming logistical and practical concerns with the manual method. Therefore, this project aimed to establish whether the FARO Focus 3D scanner and FARO Zone 3D software can improve the accuracy of area of origin estimates relative to the manual method. We created a series of eight bloodstain impact patterns and performed paired analysis using the two methods to estimate areas of origin for each pattern. Our data suggested that FARO-derived estimates were generally more accurate than using the manual method. FARO-estimated heights of origin areas were generally closer to the true distance. Both methods underestimated the distance from the wall for most patterns originating 150mm or greater from the wall, but overestimated distances for patterns originating closer to the wall. The degree to which distances were underestimated increased significantly the further the blood source was from the wall and was greater for FARO-derived estimates. The results of this research contribute to the validation of these instruments for operational implementation for BPA and should be considered alongside the practical benefits of 3D scanning relative to manual methods. Further, 3D scanning can provide reliable BPA reconstruction documentation for technical review and court presentation.     

Differential association in group and solo offending

The relationship between association with deviant peers and offending is a longstanding interest in criminology, however, the mechanisms that produce the relationship are seldom investigated. As a result, theoretical links between differential association and offending are often speculative. Differential association theorists maintain that interaction with deviant peers results in cognitive changes that make offending more attractive. Others contend that peers' influence on offending is enacted via group situations where associates encourage crime by offering opportunities or situational inducements. Using data from the National Youth Survey (NYS), this study explored the influence of delinquent friends' behaviors and attitudes on general, group, and solo offending for three crimes. OLS regression analyses supported differential association theory as originally written and no evidence was found that its effects were contingent on the presence of co-offenders. Implications of this exploratory analysis for differential association theory are provided along with directions for future research.     

What Levels of Racial Diversity Can Be Achieved with Socioeconomic‐Based Affirmative Action? Evidence from a Simulation Model

This paper investigates to what extent socioeconomic status (SES)‐based affirmative action in college admissions can produce racial diversity. Using simulation models, we investigate the racial and socioeconomic distribution of students among colleges under the use of race‐ or SES‐based affirmative action policies, or targeted, race‐based recruitment policies. We find, first, that neither SES‐based affirmative action nor race‐targeted recruiting on their own produce levels of racial diversity achieved by race‐based affirmative action. However, the two policies in combination, although likely expensive, may yield racial diversity comparable to race‐based affirmative action. Second, the use of affirmative action policies by some colleges reduces the diversity of similar‐quality colleges without such policies. Third, the combination of SES‐based affirmative action and race recruiting results in fewer academically‐overmatched Black and Hispanic students than under race‐based affirmative action, but the schools that use both also see a reduction in the academic achievement of enrolled students.     

Contracting for management: Assessing management capacity under alternative service delivery arrangements

Contracting critics suggest that when governments outsource, they reduce their capacity to produce services and manage service delivery. In this paper, we decompose the service delivery decision into service production and service management components. When governments contract for service production, they may also choose to contract for a portion of service delivery management. Studies that only compare the management activities of contracting and direct service delivery governments, without examining the management activities contracted to vendors, are likely to be incomplete and biased. Drawing on a unique survey of governmental refuse collection service directors, matched with a survey of refuse collection vendors operating under municipal contracts, we show that the vendors' management activities offset the decline in management capacity that occurs when governments contract for service delivery for this particular service. Governments can “buy” management activities when contracting for service production. © 2006 by the Association for Public Policy Analysis and Management