Courts and Policing

One of the worst-kept secrets in law enforcement - that there is little science behind many standard investigative practices - is getting the sunshine treatment. A new National Research Council study concludes that crime-investigation practices across the country are inconsistent: who collects the evidence, how it is processed, and how it is interpreted vary from coast to coast. Moreover, no current scientific method ensures the accuracy of many common investigative tools.

A National Academy of Sciences report addresses the science-or lack thereof-in America's crime labs and criminal justice system. John Roman explains why a new era of scientific policing may be at hand.

The primary goal of this research is to estimate the costs and benefits of serving misdemeanor DUI offenders in the Anchorage Wellness Court (AWC), a specialized court employing principles of therapeutic jurisprudence. The Urban Institute conducted an impact and a cost-benefit analysis (CBA) to estimate the effectiveness of the AWC. The study focused on the impact of the program on reducing the prevalence and incidence of new criminal justice system contact. Costs were collected to estimate the opportunity cost of the AWC. Recidivism variables were monetized to estimate the benefits from crime reductions. Outcomes were observed at 24, 30, 36, and 48 months.

The study compared traditional crime solving to biological evidence techniques in hundreds of cases where biological evidence was available. When conventional investigative techniques were used, a suspect was identified 12 percent of the time, compared to 31 percent of the cases using DNA evidence. In eight percent of cases built on traditional evidence alone a suspect was arrested, compared to the 16 percent arrest rate in DNA cases. The average added cost for processing a single case with DNA evidence was about $1,397. Each additional arrest-an arrest that would not have occurred without DNA processing-cost $14,169.

DNA evidence isn't a typical tool for investigating property crimes like burglary, but a new Urban Institute report reveals that biological evidence can be remarkably effective in solving and prosecuting such crimes.