How to Write an Investigation Report: Templates and Examples

6/13/2026

A workplace investigation report is written for three readers who will never be in the same room: the decision-maker who acts on it, the agency investigator who may audit it, and the plaintiff's attorney who will try to dismantle it. A report that satisfies the first and ignores the other two is the most common failure in HR investigations.

Quick answer: Use a consistent template every time. State allegations as discrete factual claims, attribute every contested fact to its source, include contrary evidence, explain credibility determinations with articulated factors, and reach an explicit conclusion on each allegation. Avoid legal conclusions and keep recommendations separate from findings.

The Template

Copy this structure for every matter. Consistency across reports is itself evidence of a reliable process.

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CONFIDENTIAL — WORKPLACE INVESTIGATION REPORT

Matter: [Reference number] Complainant: [Name, title, department, tenure] Respondent: [Name, title, department, tenure] Investigator: [Name, title] Date complaint received: [Date] Investigation period: [Start] to [End] Report date: [Date] Distribution: [Names and titles]

1. BACKGROUND How the complaint arose, how it was received, the parties' roles and reporting relationship, relevant history, and any interim measures implemented.
2. SCOPE AND METHODOLOGY What was investigated, by whom, over what period, the standard of proof applied (preponderance of the evidence), and what methods were used — interviews, document review, data review.

III. ALLEGATIONS Each allegation as a separate, numbered, discrete factual claim.

1. EVIDENCE REVIEWED Witnesses interviewed with dates; documents examined; data reviewed; anything requested but not obtained, and why.
2. FACTUAL FINDINGS Organized by allegation. Undisputed facts first, then disputed facts with each party's account attributed.
3. CREDIBILITY ANALYSIS Only where accounts conflict. Explained against articulated factors.

VII. CONCLUSIONS Substantiated, not substantiated, or inconclusive, per allegation, tied to specific policy provisions.

VIII. RECOMMENDATIONS Separated from findings. Corrective, preventive, and monitoring.

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Section III: Worked Examples of Allegation Statements

An allegation must be provable or disprovable. Compare:

Insufficient	Usable
"Complainant alleges harassment."	"Allegation 1: On or about April 8, 2026, in the second-floor conference room, Respondent placed his hand on Complainant's shoulder and stated words to the effect of 'you should smile more, it suits you.'"
"Complainant alleges discrimination in scheduling."	"Allegation 2: Between January and May 2026, Respondent assigned weekend shifts to Complainant on 14 occasions while assigning weekend shifts to comparably situated employees on an average of 4 occasions."
"Complainant alleges retaliation."	"Allegation 3: On May 3, 2026, eight days after Complainant reported the conduct in Allegation 1 to HR, Respondent removed Complainant from the Henderson account, which she had managed since 2024."

Section V: Worked Example of Factual Findings

"Allegation 1.

The following facts are undisputed. Complainant and Respondent attended a project meeting in the second-floor conference room on April 8, 2026, beginning at approximately 10:00 a.m. Witness A and Witness B also attended. Badge records confirm all four individuals entered the second floor between 9:52 and 9:58 a.m.

The parties' accounts differ as to what occurred at the conclusion of the meeting.

Complainant stated that as the meeting ended and others were gathering materials, Respondent placed his hand on her right shoulder and said, 'You should smile more, it suits you.' She stated she stepped away without responding and left the room. She stated she felt embarrassed and did not want to react in front of colleagues.

Respondent stated he does not recall touching Complainant. He acknowledged he may have said something 'about her seeming stressed' but denied any comment about her appearance and denied any physical contact.

Witness A stated she was facing away and did not observe physical contact, but recalled hearing Respondent say something to Complainant that included the word 'smile,' and recalled that Complainant left the room without responding.

Witness B stated he had already left the room and observed nothing.

Complainant produced a text message sent to a personal contact at 10:34 a.m. on April 8, 2026, stating, 'he did the smile thing again and touched my shoulder in front of everyone.' The message was provided in a screenshot showing the timestamp."

Note what this passage does: it attributes every contested fact, includes the account favorable to the respondent, includes the witness who saw nothing, and presents corroborating evidence without characterizing it.

Section VI: Worked Example of Credibility Analysis

"Where the accounts of Complainant and Respondent conflict regarding the April 8 incident, I credit Complainant's account for the following reasons.

First, Complainant's account has been consistent across her initial report to HR on April 21, her interview on April 24, and the contemporaneous text message she sent on April 8 at 10:34 a.m., before any complaint was made.

Second, Witness A independently recalled hearing a comment including the word 'smile' and recalled Complainant leaving without responding, which is consistent with Complainant's account and inconsistent with Respondent's recollection of a comment about stress.

Third, Respondent's account is one of non-recollection rather than affirmative denial as to the physical contact, which carries less weight than a specific contrary account.

Fourth, I identified no evidence of a motive for Complainant to fabricate. Her most recent performance review was 'exceeds expectations,' no disciplinary action was pending, and she and Respondent had no documented prior conflict.

I note that Complainant's delay of thirteen days in reporting could bear on credibility. Complainant explained the delay as reluctance to escalate a matter involving a senior colleague, which is a common and plausible explanation, and the contemporaneous text message substantially offsets the concern."

That final paragraph — acknowledging and addressing the weakness in your own conclusion — is what distinguishes a credible report from an advocacy document.

Section VII: Conclusion Language

Substantiated:"The evidence supports a finding, by a preponderance of the evidence, that Respondent made the statement and physical contact described in Allegation 1. This conduct violates Section 4.2 of the Respectful Workplace Policy, which prohibits unwelcome physical contact and comments regarding personal appearance."

Not substantiated:"The evidence does not support a finding, by a preponderance of the evidence, that the conduct described in Allegation 2 occurred. This is not a finding that the conduct did not occur; it is a finding that the available evidence does not establish it as more likely than not."

Inconclusive:"The available evidence does not permit a determination as to Allegation 3. The only direct accounts are those of the parties, they conflict, no corroborating evidence was identified, and I was unable to identify a basis to credit one account over the other."

Adapting by Case Type

Case Type	Emphasis
Harassment	Each incident stated separately; the welcomeness and severity/pervasiveness facts; contemporaneous complaints to third parties
Discrimination	Comparator analysis; documented decision rationale; statistical patterns where available
Retaliation	Protected activity date; decision-maker knowledge; timing; consistency of the stated reason
Theft or fraud	Documentary and system evidence; chain of custody; access records
Policy violation	Whether the policy was communicated; how it was enforced against others
Safety	Physical evidence; training records; prior incidents; corrective action

Quality Checklist Before Finalizing

• Every allegation has an explicit conclusion
• Every contested fact is attributed to a source
• Contrary evidence appears and is addressed
• Credibility determinations cite articulated factors
• Weaknesses in the conclusion are acknowledged
• No legal conclusions unless counsel directed otherwise
• No medical, disability, or irrelevant personal information
• Recommendations separated from findings
• Dates, names, and titles verified
• Tone reads as neutral to a stranger

Frequently Asked Questions

How long should the report be?

Most single-complainant matters produce 5 to 12 pages. Length should track the number of allegations and witnesses, not the investigator's diligence.

Should the report be privileged?

Decide at the outset with counsel. Note that asserting the reasonable-care defense often waives privilege over the investigation, so the decision is a genuine tradeoff.

Do the parties receive the report?

Usually not the full report. Provide a written closure letter at an appropriate level of detail.

Can I include my impressions?

Credibility assessments belong in the report expressed against factors. Personal impressions and characterizations do not.

What if I cannot reach a conclusion?

"Inconclusive" is a legitimate finding. State it clearly and explain why, rather than forcing a determination the evidence does not support.

Report Writing Is the Skill That Gets Tested

Interview technique determines what you learn. The report determines whether anyone can rely on it.

The Internal Investigations Certificate Program includes report drafting with practice exercises. For complex matters, the Advanced Internal Investigations Certificate Program goes further into credibility and evidentiary standards.

👉 See the Workplace Investigation Training Program →

Additional resources: Workplace Investigations FAQs | How to Write an Investigation Summary | Glossary of Workplace Investigation Terms