Criminal and Civil Investigation Procedure
Two tracks, different rules
Civil matters run on pleadings, discovery, and a preponderance standard; criminal matters run on investigation, charging, and proof beyond a reasonable doubt. Know the discovery tools: interrogatories, requests for production, requests for admission, depositions, and subpoenas. A subpoena commands appearance; a subpoena duces tecum commands production of documents. Investigators generally cannot issue subpoenas themselves - only attorneys, courts, or specified agencies can.
Working for counsel
When retained by an attorney, work product and attorney-client privilege may protect communications, but not the underlying facts. Assume everything else is discoverable. Service of process requires statutory appointment or authorization in most jurisdictions, and a PI license alone rarely confers it.
Arrest and detention
Private citizens have narrow citizen's-arrest authority in some jurisdictions and none in others. Investigators should not detain, search persons, or use force absent an imminent threat to safety. Preservation letters, litigation holds, and prompt secured storage protect evidence before formal process arrives.
Traps
- Assuming privilege covers factual observations you made.
- Serving process without the required appointment.
- Promising a client an outcome that depends on a prosecutor or a jury.
- Missing a preservation deadline while waiting for a subpoena response.
Rule of thumb
Know the forum, the standard, and who your client is. Ask whether the product will be used in a civil filing, a criminal referral, or an internal HR decision - the answer changes the documentation you need.