Investigative Techniques and Case Management
Domain 4: Investigative Techniques and Case Management
This domain tests interviewing, statement-taking, evidence collection, documentation, report writing, and case-file integrity. The exam rewards a repeatable process that produces admissible, credible work product.
Core rules
- Interviewing: separate witnesses, start with open-ended questions, then narrow. Avoid leading questions and promises of leniency. A custodial-style confrontation by a private investigator can become false imprisonment or coercion; the interviewee must be free to leave.
- Statements: record the date, time, place, people present, and whether the person was free to leave. If written, have the witness read, correct, and sign or initial each page. Preserve the original; work from copies.
- Evidence: photograph the item in place before moving it, use scale and identifier, log every transfer, and store in a locked location. Digital evidence should be copied with hash values when practicable.
- Reports: write in chronological order, distinguish observation from inference, use exact quotes, and avoid conclusory labels such as "thief" or "liar." Correct errors with a dated addendum, not by rewriting the original.
- Case-file integrity: index documents, control access, retain files under the contract and statute, and never alter a file after a legal hold.
Worked example
A witness says the subject "was always around the cash register." In the report, record the exact words, then add: "Witness did not state that she saw the subject take cash." This preserves the statement while preventing the reader from inferring guilt. A later interview with a second witness is kept separate.
Traps
Putting opinions in the report. Recording over original media. Letting the client dictate the conclusion. Failing to document that an interviewee was free to leave.