Final answer:
The absence of a proper chain of custody for evidence can lead to evidence being deemed inadmissible, preventing proof of guilt beyond a reasonable doubt and possibly causing wrongful convictions or case dismissals.
Step-by-step explanation:
If chain of custody is not established for evidence, the consequences could be significant, particularly in a criminal trial. The chain of custody refers to the chronological documentation that records the sequence of custody, control, transfer, analysis, and disposition of materials, including physical or electronic evidence. Without a proper chain of custody, evidence may be deemed inadmissible in court under the exclusionary rule, as set forth in cases like Mapp v. Ohio. This could lead to an inability to prove a defendant's guilt beyond a reasonable doubt, potentially resulting in the acquittal of the accused or dismissal of the case. Moreover, failure to maintain chain of custody can also result in wrongful convictions if unreliable evidence is admitted.