Bullcoming v. New Mexico
The Court ruled that a state could not use a substitute lab scientist to introduce a blood-alcohol test report when that scientist had not performed, observed, or reviewed the actual test — only the analyst who signed the certification could satisfy the defendant's right to confront witnesses.
The decision extends the Court's 2009 ruling in Melendez-Diaz v. Massachusetts to a closely related scenario, reinforcing that prosecutors generally cannot swap in a knowledgeable stand-in for the specific analyst whose findings are being offered as evidence, with major implications for how crime labs staff and schedule court appearances nationwide.
“The accused’s right is to be confronted with the analyst who made the certification, unless that analyst is unavailable at trial, and the accused had an opportunity, pretrial, to cross-examine that particular scientist.”
The Court's core holding on who must testify about a forensic lab certification.
How it got here: A New Mexico trial court admitted the report over a Confrontation Clause objection; the New Mexico Supreme Court upheld the conviction, and Bullcoming asked the U.S. Supreme Court to review that ruling.
The Case in Depth
What happened
Donald Bullcoming was arrested for driving while intoxicated after rear-ending another vehicle. Police obtained a blood sample showing a blood-alcohol concentration far above the legal threshold. At trial, prosecutors did not call the analyst, Curtis Caylor, who tested the blood and signed the report certifying the result, because he had been placed on unpaid leave. Instead they called a different lab scientist who had not performed or observed the test.
The question before the Court
Can prosecutors satisfy a defendant's right to confront witnesses by putting a different lab scientist on the stand instead of the analyst who actually tested the evidence?
Why it matters
Crime labs and prosecutors across the country must ensure the specific analyst who performed a forensic test — not merely a colleague familiar with lab procedures — testifies and faces cross-examination when the results are used against a defendant. This can strain lab staffing, drive up subpoenas, and complicate scheduling, particularly in high-volume cases like drunk-driving prosecutions.
What changes now
The case returns to New Mexico courts for further proceedings consistent with the ruling; the Court did not decide whether the error was harmless, leaving that question for the state courts on remand. This is a final decision on the merits of the confrontation question, though it does not resolve every scenario involving lab reports, retesting, or supervisory testimony, some of which the concurrence expressly reserved for future cases.
What this does not decide
The concurrence stresses the ruling does not address whether a supervisor with some connection to the test could testify, whether an expert could give an independent opinion based on unadmitted reports, whether purely machine-generated raw data without an analyst's certification would need the same testimony, or reports created for reasons other than trial evidence, such as medical treatment.
Concurrences and dissents
Concurrence in part — Justice Sotomayor
Justice Sotomayor agreed the report was testimonial and wrongly admitted, emphasizing that its 'primary purpose' was to create evidence for trial rather than to serve some other administrative function. She wrote separately mainly to stress how narrow the ruling is, listing several factual scenarios — such as supervisory testimony, independent expert opinions, or purely machine-generated data — that this case does not resolve.
Dissent — Justice Kennedy
“In these circumstances, requiring the State to call the technician who filled out a form and recorded the results of a test is a hollow formality.”The dissent's central objection that the majority's rule imposes an unnecessary requirement.
Justice Kennedy argued the majority wrongly extended Melendez-Diaz to bar testimony from a knowledgeable lab representative who explained the testing process and was fully cross-examined, even though he was not the analyst who filled out the form. He contended reliability safeguards like retesting and cross-examination already protected defendants, and warned the ruling would impose unworkable burdens on state labs while displacing states from crafting their own evidentiary rules.
How the Court got there
The legal reasoning, step by step
- The Court applied the rule from Crawford v. Washington that testimonial out-of-court statements cannot be admitted against a defendant unless the person who made the statement is unavailable and the defendant had a prior chance to cross-examine that specific person.
- Building on Melendez-Diaz v. Massachusetts, which held that a forensic certificate created to prove a fact at trial counts as a testimonial statement, the Court found the blood-alcohol report here served the same evidentiary purpose and was therefore testimonial.
- The Court rejected the New Mexico Supreme Court's view that the certifying analyst was a mere 'scrivener' who exercised no judgment, noting that the analyst had certified multiple facts about handling and testing the sample beyond just reading a machine number.
- Because the substitute witness had not performed, observed, or reviewed the actual test, he could not speak to what the certifying analyst knew, observed, or might have gotten wrong, so his testimony could not stand in for cross-examining the analyst himself.
- The Court concluded that admitting the report through a surrogate witness violated the defendant's right to confront the specific analyst whose certification was used against him, regardless of whether the substitute witness understood the lab's general procedures.
Doctrinal impact
Cases affected by this decision
Reaffirms Melendez-Diaz v. Massachusetts (557 U.S. 305)
Applied and extended its rule that forensic certificates created for trial require live testimony from the actual analyst.
Reaffirms Crawford v. Washington (541 U.S. 36)
Relied on its rule that testimonial statements require an unavailable witness and prior cross-examination opportunity.