Investigative Techniques and Evidence Handling
Investigative Techniques and Evidence Handling
This domain tests lawful collection, documentation, and preservation. Indiana investigators must match the technique to the legal authority: public observation, consented interviews, lawful recording, and properly obtained records. The goal is evidence that is authentic, admissible, and defensible.
Core rules
- Surveillance in public is generally permissible; private property, trespass, and reasonable expectations of privacy are limits.
- Indiana generally allows recording a conversation when the investigator is a party or one party consents; do not record conversations where no party consents.
- Keep contemporaneous notes, original photographs, and unaltered digital files. Document date, time, location, and chain of custody.
- For digital evidence, preserve the original, create a working copy, record hash values, and log every transfer.
- Interviews: identify yourself truthfully, record consent, separate facts from opinions, and avoid leading questions.
Worked example
An investigator photographs a subject in a public parking lot and later receives a USB drive from a witness. The photos are lawful because the lot is public. For the USB, the investigator photographs the drive, labels it, records a hash, copies it to a working folder, and logs the witness's name, date, and transfer. The report states what was observed and what was received, not conclusions the evidence cannot support.
Traps
Do not record a conversation between two other people without consent. Do not edit original images or "clean up" files. Do not rely on memory alone; late notes lose weight. Do not break the chain of custody by leaving evidence unlabeled or passing it around. Do not confuse suspicion with proof in reports.