Writing investigation reports clients understand

The report is the part of your work the client actually holds. Pursuit Magazine’s case-management framework is blunt about the stakes: “A perfectly planned and executed investigation can still be tanked by a lousy report.”

Our PI report template guide covers what goes in a report: the sections, in order. This guide is about how to write it so that a client, an adjuster, an attorney and, sometimes, a stranger reading it a year later all understand the same thing.

Know who will read it

Your first reader is usually the client. But reports travel: to an attorney, to opposing counsel, to a claims committee, to a judge. Write for the least-informed reader who might reasonably pick it up, someone intelligent who wasn’t there and doesn’t know your shorthand.

Before you start, answer two questions in one sentence each:

1. What did the client ask? (“Is the claimant performing physical work inconsistent with his claimed injury?”)
2. What’s the short answer? (“On two of four days, the claimant was observed lifting and carrying loads; details and video below.”)

If you can’t write the second sentence, the report isn’t ready.

Lead with the answer

Busy readers read the top and skim the rest. Put a short summary of findings near the start (three to six sentences) that answers the client’s question and points to where the detail is. Then give the chronology.

Don’t save the key observation for page seven for dramatic effect. It isn’t a novel, and the reader who stops at page two should still come away with the right picture.

Separate what you saw from what you think

This is the most important habit in investigative writing.

• Observation: “At 07:52 the subject carried two 5-gallon buckets from the garage to the truck bed, one in each hand.”
• Inference: “The buckets appeared full, based on how he carried them.”
• Opinion or conclusion: “The subject appears capable of lifting heavy loads.”

All three can have a place, but they must be distinguishable. Write the observations plainly in the body. If the client wants your assessment, give it in a separate, clearly labeled section (“Investigator’s assessment”), with the observations it rests on. Never let an inference pass as an observation. “The subject was drunk” is an inference; “the subject was unsteady on his feet and dropped his keys twice” is what you saw.

Avoid loaded words that carry a conclusion in with them: admitted, claimed, sneaked, clearly, obviously, evasive. Use said, stated, walked, left.

Write times, names and places the same way every time

Inconsistency makes a reader wonder what else is inconsistent.

• Times: pick one format (24-hour, or 12-hour with a.m./p.m.) and the time zone, and use it throughout. Say where your times come from: “Times are from the investigator’s watch, checked against network time at the start of each day.”
• Dates: write them out in the body (“Monday, September 14, 2026”) or use one numeric format consistently.
• People: introduce each person once with full name and role, then use one short form. “Mark Ellis (the subject)” then “Ellis” or “the subject,” not both in alternation. Describe unidentified people consistently too: “unidentified male #1 (UM1): white, about 30, gray hoodie.”
• Places: full address the first time, then a short, consistent label (“the residence”).

Use plain language

Federal plain-language guidance, written for government documents but just as useful here, comes down to a few habits:

• Short sentences. One observation per sentence in the chronology.
• Active voice. “The subject drove to the store,” not “the store was driven to.”
• Common words. “Went,” not “proceeded.” “Car,” not “the aforementioned vehicle.”
• Explain jargon or drop it. “Loss of subject” might mean nothing to a claims committee. “I lost sight of the subject’s vehicle at the intersection of Main and 5th” means the same to everyone.
• Headings and lists that make the structure obvious.

Plain writing isn’t less professional. It’s harder to misread, and it shows you have nothing to hide behind.

Report the negatives

What you didn’t see matters as much as what you did. If you watched a residence for nine hours and the subject never came out, say so, with the hours. If a records search found nothing, say which records, where and when. Omitting quiet days makes the report look selective, and a selective report is easy to attack.

Also say what limited your observations: weather, obstructed views, a lost signal, a camera that failed. Being upfront about limits makes the rest of the report more credible.

Make exhibits easy to follow

Every photo, clip and document you refer to should have an exhibit number and be referred to by that number in the text: “At 14:22 the subject lifted a tire into the truck (Exhibit 7, video, 00:00–00:41).”

• Put an exhibit index at the end: number, description, date and time, file name and, ideally, a SHA-256 hash so the recipient can check each file (see verifying an evidence file hash).
• Caption stills with date, time and what they show, in neutral words.
• If a clip is trimmed from a longer original, say so and name the original.

Edit like the other side is reading

Before you deliver:

1. Read it once as the client. Does the summary answer their question?
2. Read it once as a hostile reader. Where could someone say “how do you know that?” Every such spot needs an observation, a source or a rewording.
3. Check every number: times, hours, dates, plate numbers, addresses, against your log.
4. Check names and spellings, especially the subject’s.
5. Read it aloud, or have a colleague read it. Clumsy sentences show up immediately.

Resist rewriting history. If your log says 14:25 and your memory says 14:20, the report says 14:25.

Deliver it well

A clear report delivered as an email attachment to the wrong address undoes the work. Deliver through a channel that keeps it confidential and lets you see that it arrived (see sharing files securely with clients), and follow it with a short call if the findings are significant. Pursuit Magazine’s piece on modern report delivery treats the delivery itself as part of the product. Clients notice when it’s easy.

A quick checklist

• The first paragraph answers the client’s question.
• Observations, inferences and opinions are clearly separated.
• Times, dates, names and places are consistent throughout.
• Quiet periods and limitations are reported.
• Every exhibit is numbered, referred to and indexed.
• It reads cleanly aloud.

The free investigation report outline gives you the structure; these habits make it readable.

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