In the case of California v. Trombetta et al., 1983, the U.S Supreme Court ruled that law enforcement is not required to preserve breath samples from breathalyzer tests in DUI cases for defendants to retest later. The court held that due process does not require police agencies to maintain such evidence on behalf of defendants unless it possesses an exculpatory value apparent before being destroyed and be of such a nature that the defendant would be unable to obtain comparable evidence by other reasonably available means. This decision was based on two main reasons: first, at the time of collection, there's no significant evidentiary use or relevance known; secondly, alternative methods exist for challenging blood-alcohol readings' reliability. Therefore, destroying these samples did not violate any constitutional rights.

In the dissenting opinion for California v. Trombetta, Justice Thurgood Marshall argued that the majority's decision failed to adequately protect defendants' rights under the Fourteenth Amendment's due process clause. He contended that by not requiring law enforcement agencies to preserve potentially exculpatory evidence (in this case, breath samples from a drunk driving arrest), they were denying defendants an opportunity to challenge their charges effectively. Marshall believed it was unreasonable and unfair to expect defendants themselves to request preservation of such evidence at the time of collection since they may be unaware of its potential significance or even existence. He also disagreed with the majority’s assertion that alternative methods existed for challenging blood-alcohol tests’ reliability; he felt these alternatives were inadequate substitutes for direct examination of collected samples.