This one is written for counsel.

The investigator on the other side of your case has probably used an AI tool somewhere on the file. To organize discovery, to summarize interviews, to draft a report, to rank addresses in a locate. That by itself proves nothing. Used well, these tools make an investigator faster without making him less accurate.

The question worth asking is not whether he used AI. It is whether he can show which of his findings passed through an AI-assisted step, and what he checked each one against. An investigator who kept that record will answer calmly. One who did not will discover, in front of you, that he cannot separate what he verified from what a tool told him.

I am an investigator, not a lawyer. What follows is what I would want asked of me, and what I know an unprepared investigator cannot answer. What is discoverable and how you get it is your call.

First, what the existing rules may reach

None of this requires a new AI rule. The existing ones may already reach it, depending on the investigator's role in the case.

If he is a retained testifying expert, his report must disclose "the facts or data considered by the witness in forming" his opinions. Fed. R. Civ. P. 26(a)(2)(B)(ii). There is a fair argument that AI-generated summaries, chronologies or rankings he reviewed while forming an opinion are facts or data he considered. Drafts of the report itself are protected, Fed. R. Civ. P. 26(b)(4)(B), and so are most attorney-expert communications. The exceptions include communications that identify facts or data the attorney provided and the expert considered, or assumptions the attorney provided and the expert relied on. Fed. R. Civ. P. 26(b)(4)(C)(ii)-(iii).

If he worked the case as a fact investigator, documents he prepared in anticipation of litigation or for trial may be protected as trial-preparation materials prepared by a party's "agent," discoverable only on a showing of substantial need and undue hardship. Fed. R. Civ. P. 26(b)(3)(A). That protection covers documents and tangible things. It does not shield the underlying facts.

If he is a consulting expert who will not testify, his facts and opinions are ordinarily off limits absent exceptional circumstances. Fed. R. Civ. P. 26(b)(4)(D).

If he refreshed his memory from an AI-generated summary, that document can come into the room. When a witness uses a writing to refresh memory while testifying, the adverse party may have it produced, inspect it, cross-examine on it, and introduce the relevant portions. If he used it before testifying, the court may order the same where justice requires. Fed. R. Evid. 612(a)-(b).

That last one is the one most often overlooked. An investigator who read his AI chronology in the hallway before taking the stand, and relied on it to refresh his memory, may have just made it producible.

The questions

The tool and the task

"Which AI tools did you use on this file, and what did you ask each one to do?" A prepared investigator names the tool and the task without hesitating. Vagueness here usually means he never wrote it down.

"What material did you put into it? Was any of it privileged, sealed, or personal information about a party, and was it redacted first?" This goes to his judgment and, depending on the tool and the account he used, to whether confidential material left his control. A consumer chat account and an enterprise deployment with data controls are not the same thing, and he should know which one he was using.

Verification

"Pick a finding in the report. Was an AI tool involved at any step between the source and this sentence?" Choose a specific finding, not the report in general. General questions get general answers. A specific finding forces him to trace it.

"What primary source did you check it against, and when?" The answer you want to hear from your own investigator is a page, a Bates number, a record, a date. The answer that opens a door is "I reviewed it."

"Did the tool produce anything you threw out? What, and why?" This is the most useful question on the list, and it cuts both ways. If he threw nothing out, either the tool was never wrong, which is unlikely on any volume of material, or he did not check. If he threw things out, he has just told you the tool made errors on this file, and you can ask how he knows he caught all of them.

Documentation

"Do you keep a record of the AI-assisted steps on your files? Produce it for this one." A disciplined investigator keeps a log: the tool, the task, what went in, what came back, what it was checked against, who checked it, and what happened to it. If there is no log, every answer above rests on his memory.

"Before you testified today, did you review any AI-generated summary, timeline or chronology?" This is the Rule 612 question. Ask it plainly.

The words on the page

"Did any of the language in this report come from an AI draft?" Draft tools tend to upgrade verbs and add conclusions. "Reviewed" becomes "conducted a comprehensive analysis of." "Documented the subject entering at 0714" becomes "confirmed the subject is working." If his report characterizes his own findings more strongly than his notes support, the gap between the notes and the report is where to press.

What the answers tell you

None of these questions is a trap for an investigator who worked carefully. He will answer each one in a sentence and hand you a log. That is the point: the questions separate documented method from confident recollection, and on the stand those look identical until someone asks.

An investigator who cannot say which of his findings came through an AI-assisted step cannot say which of them he verified. That is not an AI problem. It is a methodology problem that AI made easier to create.

Ask your own investigator first

Every question above applies to the investigator on your side. The time to find out he cannot answer them is before opposing counsel does. Run the list with him before his deposition. If he has no log, he has time to reconstruct what he can from his own file, and you have time to decide how much of his work you want to rest on.

This article draws on Chapter 13 of The AI-Powered Private Investigator, which covers AI disclosure, the audit trail, and testimony preparation. I review AI-assisted investigative work for counsel and testify about how it was done. Expert witness and consulting.

Jon Jacobson, MBA, is a licensed Arizona private investigator (license #1799200) and principal of Old Pueblo Investigations in Tucson. He is not an attorney, and this is not legal advice. Discoverability depends on the jurisdiction, the posture and the investigator's role in the case. Confirm the rules that govern your matter.

Authorities

  • Fed. R. Civ. P. 26(a)(2)(B)(ii) (retained expert's report must include "the facts or data considered by the witness in forming" the opinions). Text
  • Fed. R. Civ. P. 26(b)(3)(A) (documents and tangible things prepared in anticipation of litigation or for trial by or for a party or its representative, including its "consultant" or "agent"; discoverable on showing of substantial need and undue hardship). Text
  • Fed. R. Civ. P. 26(b)(4)(B) (protection for drafts of expert reports and disclosures). Text
  • Fed. R. Civ. P. 26(b)(4)(C)(i)-(iii) (protection for attorney-expert communications, except those relating to compensation, identifying facts or data the attorney provided and the expert considered, or identifying assumptions the attorney provided and the expert relied on). Text
  • Fed. R. Civ. P. 26(b)(4)(D) (non-testifying experts; discovery only under Rule 35(b) or on showing of exceptional circumstances). Text
  • Fed. R. Evid. 612(a)-(b) (writing used to refresh a witness's memory, while testifying or, where justice requires, before testifying). Text