Advances in DNA science have helped exonerate more than 270 people in the United States convicted of crimes they did not commit. But with biological evidence available in only a small percentage of court cases, research is needed to improve non-DNA forensic tools, experts told a recent meeting at AAAS.

DNA testing is being more widely used from the start of criminal investigations, a development that should help reduce wrongful imprisonments, said Kenneth Melson, acting director of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.