Commonwealth v. Yohe, 621 Pa. 527

Police arrested Yohe for DUI and his blood was drawn and sent to NMS Labs for BAC testing.
NMS Labs ran three tests: one enzymatic assay (by Megan Silcox) and two gas chromatograph (by Lisa Chacko); technicians produced raw machine printouts (aliquots) but did not sign the lab’s Toxicology Report.
Dr. Lee Blum, the lab’s assistant director/toxicologist, reviewed the raw data, validated the results, chose the lower GC value (.159%) to report, electronically signed the three‑page Toxicology Report, and testified at trial as the Commonwealth’s expert.
Yohe objected under the Sixth Amendment Confrontation Clause because the technicians who performed the actual tests did not testify; the trial court granted a new trial, concluding the technicians (the testing analysts) were the required witnesses.
The Superior Court reversed, and the Pennsylvania Supreme Court affirmed: it held the Toxicology Report was testimonial but Dr. Blum was the certifying/authoring analyst whose in‑court testimony satisfied Yohe’s confrontation rights.

Issue	Yohe’s Argument	Commonwealth’s Argument	Held
Whether admission of the Toxicology Report violated the Confrontation Clause because the technicians who ran the tests did not testify	The specific technicians who prepared and ran the aliquot tests (and thus generated the printouts) were the analysts whose in‑court testimony Yohe had a right to confront; surrogate testimony by a reviewing supervisor is insufficient	Dr. Blum authored and certified the Toxicology Report after independently reviewing raw data, comparing multiple tests, and forming the opinion reported; his live testimony satisfied the Confrontation Clause	The Toxicology Report was testimonial, but Dr. Blum — who validated the raw data, performed the critical comparative analysis, certified and signed the report, and testified — was the proper analyst to confront; no Confrontation Clause violation

Crawford v. Washington, 541 U.S. 36 (testimonial statements and Confrontation Clause framework)
Davis v. Washington, 547 U.S. 813 (primary‑purpose test for testimonial vs. nontestimonial statements)
Melendez‑Diaz v. Massachusetts, 557 U.S. 305 (forensic certificates are testimonial; ‘the analyst’ must be available for confrontation)
Bullcoming v. New Mexico, 564 U.S. 647 (surrogate testimony by an analyst who did not perform or observe the test is insufficient)
Williams v. Illinois, 567 U.S. 50 (plurality: expert’s reliance on out‑of‑court lab work may not always be testimonial; Court fragmented)
Commonwealth v. Yoke, 39 A.3d 381 (Pa. Super. Ct. decision affirming that reviewing analyst’s testimony can satisfy confrontation when the reviewer authored the report)
Commonwealth v. Barton‑Martin, 5 A.3d 363 (Pa. Super. Ct. decision holding custodian/surrogate testimony insufficient when the testing analyst did not testify)