During argument at the Supreme Court on Monday in a confrontation clause case, the justices and attorneys engaged in some spirited exchanges concerning whether defense lawyers — especially those “repeat attorneys” who appear often before the same judges and prosecutors — would be likely to take undue advantage of a rule requiring forensic technicians to testify when lab reports are admitted as evidence in drug cases.

The case, Melendez-Diaz v. Massachusetts, asks whether a forensic report identifying a substance as cocaine constitutes “testimonial” evidence under the confrontation clause of the Sixth Amendment. Under the Court’s 2004 Crawford v. Washington case and subsequent confrontation clause rulings, if the laboratory report is deemed “testimonial,” then the analyst who performed the test must testify at trial and be subject to cross-examination.