In the case of Donald Bullcoming v. New Mexico, the U.S Supreme Court ruled in favor of Bullcoming, reversing a decision made by the New Mexico Supreme Court. The issue at hand was whether or not it violated Bullcoming's Sixth Amendment right to confront witnesses against him when a lab analyst who did not perform his blood-alcohol test testified about its results during trial. The court held that surrogate testimony could not convey what an absent analyst would have seen and done during testing, thus violating the Confrontation Clause of the Sixth Amendment which guarantees defendants' rights to cross-examine witnesses against them. This ruling emphasized that forensic evidence must be presented by those who actually conducted tests or witnessed procedures rather than surrogates.

In the dissenting opinion for Donald Bullcoming v. New Mexico, Justice Anthony Kennedy, joined by Chief Justice John Roberts and Justices Stephen Breyer and Samuel Alito, argued that the majority's decision unnecessarily expanded the Confrontation Clause of the Sixth Amendment. They contended that it was not necessary for a forensic analyst who prepared a certification to testify in person at trial because this would place an undue burden on laboratories and courts without significantly improving fairness or accuracy in trials. The dissenters believed that as long as there was someone competent to explain and defend a lab report’s conclusions under oath on stand, it should suffice even if they were not directly involved with producing those results. They also pointed out potential practical problems arising from requiring every analyst involved in testing process to be available for cross-examination at trial.