Chain of custody failures rarely look like misconduct. They look like helpfulness: an IT manager copying a departing employee's mailbox to a USB stick, a paralegal browsing a laptop "just to check what's on it", a phone passed around an office before anyone thought about preservation. Each is an authenticity argument handed to the other side.
The Common Breaks
Original devices used after the dispute arose, so every file's access times now post-date the events. Copies made without write-blocking or hashing, so nothing proves the copy matches the source. No contemporaneous record of who held what, when. And well-meaning previews that alter the very metadata a S 146 presumption or S 69 business-records argument would rely on.
The Protocol That Closes Them
None of this is expensive. All of it is cheaper than briefing counsel to argue weight after the integrity of your best exhibit has been put in issue. If handling has already gone wrong, disclose it early — a documented, explained gap survives far better than one discovered in cross-examination.
Frequently Asked Questions
What Is Chain of Custody for Digital Evidence?
A contemporaneous record of who held each exhibit, when, and what was done to it — from acquisition to courtroom — supported by hash values that prove working copies still match the source. It is what lets you answer an authenticity challenge with documents rather than recollection.
Does a Custody Gap Make Evidence Inadmissible?
Not automatically — but it hands the other side an authenticity argument and can reduce the weight the court gives your exhibit. If handling has already gone wrong, disclose it early: a documented, explained gap survives far better than one discovered in cross-examination.
Why Are Hash Values so Important?
A hash recorded at acquisition (SHA-256 in current practice) is a digital fingerprint: re-verifying it at every handover proves the copy being examined is identical to what was collected, and that nothing has changed in between. Copies made without hashing leave that question open.