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.