…in all criminal prosecutions, the accused shall enjoy the right…to be confronted with the witnesses against him.
The United States Constitution guarantees the accused the right to be “confronted by the witnesses against him.” A series of court decisions in recent history have involved the application of the confrontation clause to forensic evidence.
In the past, supervisors or advisors from a lab often testified about work performed by a lower level analyst. This scenario usually put the person with more experience, and a better understanding of the methodologies, on the stand.
But recent Supreme Court decisions have changed that practice.
In Melendez-Diaz v. Massachusetts, 557 U.S. 305 (2009), and Bullcoming v. New Mexico, 546 U.S. (2011), the Supreme Court wrestled with whether forensic reports were considered “testimonial.” And if so, if only the individual who prepared the report could testify to its contents.
Then, in Williams v. Illinois 566 U.S. (2012), the court ruled that “formal” forensic reports are testimonial, and can only be introduced via the actual author of the report – meaning the analyst who performed the test. This decision has triggered changes in lab practices, including the hiring of personnel.