When a Sexual Harassment Complaint Is Filed, the Investigation Is the Case.

Most employers treat the workplace investigation as a formality — something to check off the list before deciding what to do about the complaint. It is not. The investigation is the case.

In sexual harassment litigation, the quality of the employer's investigation is often the most important factor in determining liability. A thorough, impartial, well-documented investigation can defeat a claim even when the underlying conduct was serious. A sloppy, biased, or incomplete investigation can create liability even when the underlying conduct was ambiguous.

I have conducted independent workplace investigations for employers and I have litigated sexual harassment cases on both sides. Here is what a defensible investigation actually looks like.

The Investigator Must Be Impartial — and Appear Impartial

The first question in any workplace investigation is: who conducts it? The answer matters enormously — both legally and practically.

The investigator must be someone who has no prior relationship with either party, no stake in the outcome, and no reporting relationship to the accused. In most cases, that means outside counsel or an independent HR professional — not the company's internal HR department, not the accused's supervisor, and not the company's general counsel if they also represent the accused.

The Investigation Must Be Thorough

A thorough investigation means interviewing all relevant witnesses — not just the complainant and the accused. It means reviewing all relevant documents — emails, texts, performance reviews, scheduling records, and any other materials that might corroborate or contradict the accounts of the parties.

• Interview the complainant first. Get the full account of what happened, when it happened, who witnessed it, and what documents might be relevant.
• Interview neutral witnesses before the accused. Neutral witnesses are less likely to have coordinated their accounts with either party.
• Interview the accused last. Present the specific allegations and give the accused a full opportunity to respond.
• Follow up on leads. If a witness mentions another witness, or if a document reference suggests other relevant materials, follow the lead.

The Documentation Standard

Every interview should be documented — not verbatim, but with sufficient detail to reconstruct what was said. The investigator's notes should reflect the questions asked and the answers given, not the investigator's conclusions about credibility.

The final investigation report should document the process — who was interviewed, what documents were reviewed, what the investigator found — and reach a conclusion about whether the conduct violated the company's policy. It should not be a legal brief arguing for a particular outcome.

The Response Must Be Proportionate and Prompt

If the investigation concludes that harassment occurred, the employer's response must be proportionate to the severity of the conduct and prompt enough to prevent recurrence. A response that is too lenient — a verbal warning for serious harassment — will not satisfy the legal standard. A response that is too severe — termination for a first offense of minor misconduct — creates its own legal risks.

The response must also be documented. The employer should be able to show, in subsequent litigation, exactly what action was taken, when it was taken, and why it was proportionate to the conduct.

The Complainant Must Be Protected From Retaliation

Throughout the investigation — and after it concludes — the employer must ensure that the complainant is not subjected to retaliation. This means monitoring the complainant's treatment by the accused and by other employees, and taking prompt action if retaliation occurs.

Retaliation after a harassment complaint is often more damaging — legally and financially — than the original harassment. I have seen cases where the underlying harassment was defensible but the retaliation was not, and the retaliation became the primary basis for liability.