How to Write an Investigation Summary: Findings, Conclusions, and Recommendations

6/3/2026

An investigation summary is the only part of your work most people will ever read — and the only part a plaintiff's attorney, an agency investigator, or a jury will see. It has to be complete enough to demonstrate thoroughness and disciplined enough not to create new problems.

Quick answer: A defensible investigation summary contains eight sections: background, scope and methodology, allegations stated as discrete factual claims, evidence reviewed, factual findings, credibility analysis, conclusions tied to policy, and recommendations. It states facts and policy violations — not legal conclusions — and it shows the reasoning, not just the result.

The Eight-Section Structure

Section	Purpose	Length
1. Background	How the complaint arose, who is involved, relevant employment history	2–4 paragraphs
2. Scope and methodology	What was investigated, by whom, over what period, using what methods	1–2 paragraphs
3. Allegations	Each allegation as a separate, numbered factual claim	Numbered list
4. Evidence reviewed	Witnesses interviewed with dates, documents examined, data reviewed	List
5. Factual findings	What the evidence establishes, allegation by allegation	The bulk of the report
6. Credibility analysis	Where accounts conflict, why one is credited over another	1–3 paragraphs per conflict
7. Conclusions	Substantiated / not substantiated / inconclusive per allegation, tied to policy	1 paragraph per allegation
8. Recommendations	Corrective and preventive action — separated from findings	Bulleted list

Section 3: Stating Allegations Correctly

This is where most reports go wrong at the outset. An allegation must be a discrete factual claim that can be proven or disproven — not a characterization.

Weak	Correct
"Complainant alleges a hostile work environment."	"Allegation 1: On or about March 12, 2026, Respondent said to Complainant, in the third-floor break room, words to the effect of 'you only got this account because of how you look.'"
"Complainant says Respondent is a bully."	"Allegation 2: Between January and April 2026, Respondent repeatedly raised his voice at Complainant during team meetings and criticized her work in front of colleagues on at least four occasions."

Breaking a complaint into discrete allegations produces a better investigation, not just a better report. It tells you exactly what to ask each witness.

Section 5: Writing Factual Findings

Findings state what the evidence establishes. Three rules:

Attribute every fact to its source

"Complainant stated that…" / "Witness A recalled that…" / "The badge access log shows that…" Never assert a contested fact in the investigator's own voice without attribution.

Report contrary evidence

A report that omits evidence favorable to the respondent is worse than useless — it is affirmatively damaging when the omission surfaces later. Include it, then explain why it does or does not change the conclusion.

Distinguish what is established from what is disputed

Use explicit framing: "The following facts are undisputed:… The parties' accounts differ as to…" This structure makes credibility analysis natural rather than awkward.

Section 6: Credibility Analysis Language

When accounts conflict, the report must explain the resolution. Never write "I found the complainant more credible" without reasoning. Instead, build the analysis from factors:

"Where the accounts conflict regarding the March 12 statement, I credit Complainant's account for the following reasons. First, Complainant's account has remained consistent across her initial written complaint, her interview, and her contemporaneous text message to Witness B on March 12 at 2:47 p.m. Second, Witness B independently recalled receiving a message from Complainant that afternoon describing a comment about her appearance, before any investigation began. Third, Respondent's account changed between his first and second interviews — he initially denied being in the break room on March 12, then acknowledged being there after being shown the badge log. Fourth, I identified no motive for Complainant to fabricate; her performance rating was 'exceeds expectations' at the time and no disciplinary action was pending."

That paragraph is what makes a finding defensible. It shows the reader the reasoning and lets them evaluate it.

Handle demeanor cautiously. If you rely on it at all, pair it with objective factors and acknowledge its limits.

Section 7: Conclusions — Three Permissible Outcomes

Finding	Meaning	Language
Substantiated	More likely than not that the conduct occurred	"The evidence supports a finding that… This conduct violates Section X of the [policy]."
Not substantiated	The evidence does not support a finding by a preponderance	"The evidence does not support a finding that… This is not a finding that the conduct did not occur."
Inconclusive	Evidence is genuinely in equipoise	"The available evidence does not permit a determination either way."

That parenthetical after "not substantiated" matters. Employers routinely communicate an unsubstantiated finding as an exoneration, which alienates complainants and is not accurate.

What Never Belongs in the Report

• Legal conclusions. Write "violated the anti-harassment policy," not "constituted unlawful sexual harassment under Title VII" — unless counsel directs otherwise.
• Medical or disability information beyond what is strictly necessary, and never in the main body.
• Speculation about motive unsupported by evidence.
• Editorial commentary about parties' personalities, appearance, or personal lives.
• Information about uncharged conduct that was not investigated.
• The investigator's personal opinions about whether discipline is deserved — recommendations belong in their own section, framed neutrally.
• Draft language. Every draft is discoverable. Do not circulate versions with speculative or sloppy phrasing.

Section 8: Recommendations

Keep recommendations separate from findings so that a decision-maker can accept the facts while exercising independent judgment on the response. Cover three categories:

• Corrective action regarding the individuals — framed as options with rationale, not as a demand.
• Preventive action — training, policy clarification, supervisory coaching, structural changes.
• Monitoring — follow-up check-ins at defined intervals to confirm the conduct has stopped and no retaliation has occurred.

Privilege, Distribution, and Retention

• Decide on privilege at the outset. If counsel directs the investigation, mark documents accordingly and route them through counsel. A report written without privilege in mind cannot be retroactively protected. Note that asserting the reasonable-care defense often waives privilege over the investigation — discuss the tradeoff with counsel early.
• Limit distribution to those with a genuine need to know, and record who received it.
• Store separately from personnel files, in a restricted investigation file.
• Retain per your record retention schedule and any applicable legal hold. Investigation files are frequently needed years later to establish patterns or to defend a later claim.

A One-Page Quality Check

Before finalizing, confirm:

• Every allegation is addressed with an explicit conclusion.
• Every contested fact is attributed to a source.
• Contrary evidence is included and addressed.
• Credibility determinations are explained with articulated factors.
• No legal conclusions appear unless directed by counsel.
• No medical, disability, or irrelevant personal information appears.
• Dates, names, and titles are accurate throughout.
• Recommendations are separated from findings.
• The tone would read as neutral to a stranger.

Frequently Asked Questions

How long should an investigation summary be?

Long enough to demonstrate thoroughness and no longer. Most single-complainant matters produce 5 to 12 pages. Padding invites scrutiny; brevity that omits evidence invites worse.

Should the report name witnesses?

Generally yes in the main file, since attribution is what makes findings verifiable. Consider a redacted version for wider distribution if witness protection is a concern.

Do we share the report with the parties?

Usually not the full report. Provide a written closure letter stating the outcome at an appropriate level of detail. Some jurisdictions and policies require more.

Can the investigator also decide the discipline?

It is better practice to separate the roles. An investigator who also decides discipline is more vulnerable to a bias challenge.

What if new allegations emerge mid-investigation?

Document the expansion of scope in the plan and the report. Either investigate them within the same matter or open a separate one — but never leave them unaddressed.

Report Writing Is the Skill That Gets Skipped

Most investigation training focuses on interviewing. The report is what survives, and it is where a strong investigation is most often undermined.

The Internal Investigations Certificate Program includes report drafting and findings analysis. For senior investigators handling matters likely to be litigated, the Advanced Internal Investigations Certificate Program goes further into credibility and evidentiary standards.

👉 See the Workplace Investigation Training Program →

Additional resources: Workplace Investigations FAQs | Investigation Documentation Best Practices | Glossary of Workplace Investigation Terms