In Smith v. Arizona (2024), the Supreme Court ruled unanimously that when a prosecutor''s expert witness repeats an absent lab analyst''s test results to support the expert''s opinion, the defendant has the right to cross-examine the original analyst who ran the tests. The lab analyst''s statements are testimonial evidence offered for their truth, triggering the Confrontation Clause in the Sixth Amendment: "In all criminal prosecutions, the accused shall enjoy the right to be confronted with the witnesses against him." This protection traces to English common law''s rejection of secret accusations and trial by affidavit. Justices Alito and Gorsuch wrote in March 2025 that the Court may need to reconsider its modern confrontation doctrine from Crawford v. Washington (2004), which held that testimonial statements require live testimony subject to cross-examination. The clause stops prosecutors from convicting defendants using written reports or secondhand testimony when the original witness won''t face questioning.