Last week the US Supreme Court ruled a defendant has a constitutional right to challenge the forensic evidence against them and cross-examine the analysts who prepared the evidence as witnesses for the prosecution. The ruling, decided in a 5-4 vote, reversed the conviction in the Melendez-Diaz v. Massachusetts case, a case involving the sale of cocaine. The high court rationalized its reversal on the basis of the defendant’s right to confront his accuser was violated.
This news comes after recent publications, such as the National Academy of Sciences report, that exposed a wide variability across forensic disciplines in terms of standards, methodologies and protocols that allow for potential errors. The lone exception to their findings was DNA testing and analysis, whose principles and practices have been validated extensively in order to achieve its position as the gold standard in forensic science. In fact, at least 240 incarcerated individuals have been exonerated based on the DNA evidence that, in many cases, invalidated the results from faulty tests such as analysis of hair, bullet casing, tool and bite marks, fingerprinting and handwriting.
Of concern to many dissenters of the ruling is the potential burden of preparation and analysis of criminal evidence. Current law allows the introduction of evidence without testimony of the analyst who produced the forensic report. Supporters insist that cross-examination of witnesses will help weed out not only the fraudulent analyst, but the incompetent one as well.