The U.S. Supreme Court’s decision last year in Melendez-Diaz v. Massachusetts caused an uproar among prosecutors by interpreting the Constitution to require that forensic and other evidence be presented mainly in person, not by affidavit.

On Monday, the Court heard arguments in a case that could be a vehicle for reversing that 5-4 decision (pdf) less than a year after its issuance. But that outcome appears far from certain.