Infrared Imaging of the Crime Scene: Possibilities and Pitfalls

All objects radiate infrared energy invisible to the human eye, which can be imaged by infrared cameras, visualizing differences in temperature and/or emissivity of objects. Infrared imaging is an emerging technique for forensic investigators. The rapid, nondestructive, and noncontact features of infrared imaging indicate its suitability for many forensic applications, ranging from the estimation of time of death to the detection of blood stains on dark backgrounds. This paper provides an overview of the principles and instrumentation involved in infrared imaging. Difficulties concerning the image interpretation due to different radiation sources and different emissivity values within a scene are addressed. Finally, reported forensic applications are reviewed and supported by practical illustrations. When introduced in forensic casework, infrared imaging can help investigators to detect, to visualize, and to identify useful evidence nondestructively.     

Keeping promises: A systematic review and a new classification of gang control strategies

Purpose

We argue that inadequate frameworks to compare similar gang control strategies, and the scarcity of well-designed evaluations have hindered our ability to determine the effectiveness of existing programs. This article proposes a new typology of gang control strategies to use with logic models as tools to improve gang program evaluation.

Methods

We conducted a systematic review of gang control strategy evaluation reports and created a typology from the studies identified. Studies were selected on the basis of methodological quality in order to reflect only rigorous evaluations with credible research findings.

Results

Forty-five studies were selected and reviewed. Studies were classified in homogeneous categories based on the targeted population and the objective of the strategy. We infer logic models that consider the activities, outputs, and outcomes of each type of strategy.

Conclusion

A better framework for the comparison of similar studies may allow meta-analyses to be conducted, thereby improving our knowledge of what works. Logic models can move the field forward by allowing researchers to understand why some programs work and others do not. The improvement, both in quality and quantity, of program evaluation in gang research is crucial in order to move beyond claims of promising approaches.