People accused of a crime have a right to cross-examine the witnesses against them. The U.S. Constitution's confrontation clause is clear on this, but there was a gaping loophole. In most states, prosecutors could introduce the results of forensic tests at a criminal trial without having the analyst there to testify. This meant the defense had no way to directly challenge the testing procedure or the competence of the lab personnel.
An enlightened U.S. Supreme Court ruling this week by an unusual mix of conservative and liberal justices says all criminal defendants have the right to confront lab analysts. This will give defense attorneys an opportunity to challenge what is often seen as airtight proof against their clients.
The high court's 5-4 ruling in Melendez-Diaz vs. Massachusetts recognizes the power of scientific findings and how damaging they can be when flawed. It was written by conservative Justice Antonin Scalia and joined by fellow conservative Clarence Thomas as well as Justices Ruth Bader Ginsburg, David Souter and John Paul Stevens, three of the court's liberal justices.
Recent scandals have documented numerous cases of fraud and error by the nation's crime labs, as well as whole categories of forensic findings that have been largely discredited, such as matching the chemical signatures of lead in bullets. One study found that invalid forensic testimony contributed to conviction in 60 percent of cases where a conviction was later overturned due to exonerating evidence.
By requiring the presence at trial of the technician when scientific conclusions are introduced "an analyst's lack of proper training or deficiency in judgment may be disclosed in cross-examination," Scalia wrote.
The dissent written by centrist Justice Anthony Kennedy, predicted that a "crushing burden" would be imposed on the criminal justice system by requiring busy lab personnel to be in court for trials. But that has not proved true in states like Florida that already recognize this right.
Pinellas-Pasco Public Defender Bob Dillinger says that giving defense attorneys access to lab personnel for depositions and trial testimony "works fine and is no big drain on the system." Dillinger says that only about 3 percent of cases end up going to trial, which sharply limits the extent to which lab people have to appear in court.
The ruling will cost the system time and money, but constitutional rights are binding regardless of their cost. And crime labs may adopt a higher level of professionalism and standardization, a move recommended by the National Academy of Sciences. Poorly trained technicians will have a harder time hiding behind exaggerated or erroneous written findings. That will be good for justice and a strike against wrongful convictions.