Randomized experiments in criminology: What have we learned in the last two decades?

This paper aims to review randomized experiments in criminology with offending outcomes and reasonably large numbers that were published between 1982 and 2004. A total of 83 experiments are summarized, compared with only 35 published between 1957 and 1981: 12 on policing, 13 on prevention, 14 on corrections, 22 on courts, and 22 on community interventions. Randomized experiments are still relatively uncommon, but there have been more large-scale multi-site experiments and replication programs. There have also been several experiments in which 100 or more places were randomly assigned. Relatively few experiments (only 10 out of 83) were conducted outside the United States. Meta-analyses suggest that prevention methods, correctional therapy, batterer programs, drug courts, juvenile restitution and deterrent policing were effective in reducing offending, while Scared Straight and boot camp programs caused a significant increase in offending.     

The relationship between education, experience, and police performance

This study used data from 299 police officers from 12 municipal police departments across the state of Virginia to determine the relationship between education and police performance. Performance was measured by supervisor evaluations of each officer's overall performance, communication skills, public relations skills, report writing skills, response to new training, decision making ability, and commitment to the police department. Significant correlations were found between education and most measures of performance. Most importantly, the results show a significant correlation between overall performance and education (r=24, p.<001). The only variables not proving to be significantly related to education were objective measures of the volume of arrests, number of times the officer required discipline, and number of accidents. Interestingly, the benefits of a college education do not become apparent until police officers gain experience. In addition, police, officers with only a high school diploma decreased in overall performance after five years of experience.     

Multiple deaths from argon contamination of hospital oxygen supply

During the course of routine hospital surgical procedures, three patients lapsed into hypoxic cyanosis. Two expired immediately, another after four days of coma. Investigation of the hospital's central liquid oxygen tank revealed that it had been refilled recently and was labelled both "oxygen" and "argon." Mass spectrometric analysis of gas sampled from the questioned tank revealed a predominance of argon. A discussion of the sampling technique, method of analysis, role of the criminalist, and causes of this accident is presented.