In proposing a new death penalty for Massachusetts last month, Governor Mitt Romney offered firm assurance that no innocent people would be executed: Convictions, he said, will be based on science.
According to the proposal, a death-penalty verdict would require not only an especially heinous crime, but also "conclusive scientific evidence" of guilt. If it passed, Massachusetts would become the first state to require a scientific link to a crime to impose a death sentence.
Romney's plan, however, comes at a difficult time for courtroom science. Much scientific evidence is coming under fresh attack from lawyers and judges, either for technical unreliability or for the human errors that can color the results. Even fingerprint analysis once the gold standard of scientific evidence is being questioned.