How do forensic specialists show that digital evidence was handled in a protected, secure manner...

Comprehensive and Detailed Explanation From Exact Extract:

The chain of custody is a documented, chronological record detailing the seizure, custody, control, transfer, analysis, and disposition of evidence. Maintaining this record proves that the evidence was protected and unaltered, which is essential for court admissibility.

Each transfer or access must be logged with date, time, and handler.

Breaks in the chain can compromise the legal validity of evidence.