Smith v. Arizona

In Smith's case, Arizona presented a forensic chemist to testify about drug-testing results prepared by a different analyst who never took the stand. The testifying expert had no personal knowledge of how the underlying analysis was conducted (he could only relay another analyst's conclusions) yet Smith had no opportunity to cross-examine the analyst who actually performed the work and made the forensic observations. Under the Confrontation Clause, this surrogate arrangement violated Smith's right to confront his accuser because the analyst whose observations were at issue was absent and unreachable through cross-examination of the substitute witness. The prosecution's use of a qualified expert to present the report did not cure the defect: the original analyst's unavailability for confrontation remained the constitutional violation.