Evidence Collection, Handling, and Chain of Custody
Integrity is the whole game
Evidence is only as good as the record showing it is what it claims to be and has not been altered. That record is the chain of custody: a continuous, contemporaneous log of every person who handled the item, when, where, and why. Opposing counsel attacks gaps, not intentions.
Handling sequence
- Document before you collect - photograph or video the item in place, with scale and context, before moving it.
- Assign a unique identifier (case number plus item number) at the moment of collection and never renumber.
- Package appropriately - breathable paper for damp or biological items, rigid or antistatic containers for electronics, tamper-evident seals with initials written across the seal.
- Log every transfer - date, time, from, to, purpose, signature. A handoff to the client is a transfer and needs a signed receipt.
- Store securely with limited access; never leave evidence in a vehicle or an unsecured office.
Digital evidence
Preserve the original: do not browse, open, or tidy the source device or file. Work from a verified copy, record a hash of the original at acquisition, keep native format and metadata (do not re-encode video or convert photos), and log every copy. Screenshots alone rarely survive authentication challenges.
Traps
- Tennessee is a one-party consent state for recording conversations: a participant may record, but an investigator who is not a party generally may not. Do not confuse audio rules with video - recording where a person has a reasonable expectation of privacy is unlawful.
- Investigators have no greater search authority than any other citizen. A seizure without consent or lawful authority taints the item no matter how good the log is.
- Handing everything to the client with no receipt destroys the chain.
Rule of thumb: if you cannot answer who touched this, minute by minute, from seizure to hearing, you have no chain of custody.