An Employer's Guide to Internal Investigations

Internal investigations are one tool employers can use when responding to workplace concerns. A well-run investigation helps an employer understand what happened, protect employees, correct misconduct, and create a record showing that the concern was taken seriously.

When Should an Employer Conduct an Internal Investigation?

An internal investigation may be needed when an employer receives a complaint or becomes aware of facts suggesting possible misconduct. Common triggers include allegations of harassment, discrimination, retaliation, workplace violence, safety concerns, wage and hour issues, theft, policy violations, conflicts of interest, or other employee misconduct.

Employers should not wait for a formal written complaint before acting. If management knows, or reasonably should know, about a serious workplace concern, the employer should assess whether an investigation is needed.

Step One: Define the Scope and Choose the Right Investigator

Before interviews begin, the employer should identify what the investigation is about. A clear scope helps keep the process focused and prevents the investigation from becoming unnecessarily broad.

Employers should consider:

• What allegation or concern triggered the investigation
• Which policies, laws, or workplace expectations may be implicated
• Who may have relevant information
• What documents, messages, records, or videos may exist
• Whether immediate interim action is needed

The investigator should be impartial, credible, and capable of documenting the process clearly. Depending on the situation, that may be someone in HR, a manager outside the chain of command, outside counsel, or a third-party investigator.

The EEOC has stated that an employer should conduct a prompt, thorough, and impartial investigation, and that the alleged harasser should not have direct or indirect control over the investigation. That principle applies more broadly: the person leading the investigation should not have a conflict of interest, personal involvement, or a stake in the outcome.

Step Two: Preserve Evidence and Manage Immediate Risk

Once an employer reasonably anticipates litigation or a legal claim, preserving relevant evidence becomes especially important. Depending on the issue, relevant evidence may include emails, text messages, workplace chat messages, personnel files, disciplinary records, timekeeping records, payroll records, security footage, access logs, complaint records, or performance evaluations.

Some investigations also require immediate interim measures before the investigation is complete. Examples may include temporary reporting changes, schedule changes, remote work, administrative leave, or separating employees. These measures should be tailored to the situation and should not punish the employee who raised the concern.

Step Three: Gather Facts Through Interviews and Document Review

Interviews are often the core of an internal investigation. Generally, the complaining employee, the accused employee, and witnesses who may have relevant information should be interviewed. A good interview should be professional, focused, and non-accusatory. The investigator should ask open-ended questions first, then follow up with more specific questions. For example:

• What happened?
• When did it happen?
• Who was present?
• What did you see or hear directly?
• Are there any supporting documents, messages, or other records?
• Did you tell anyone else?
• Has anything similar happened before?
  Is there anything else we should know?

Step Four: Protect Confidentiality and Anti-Retaliation Rights

Confidentiality matters, but employers should be careful not to promise complete secrecy. The employer may need to share information to conduct interviews, review evidence, consult counsel, comply with legal obligations, or take corrective action.

A better approach is to ask participants to respect the integrity of the investigation, avoid retaliation, preserve evidence, and refrain from interfering with witness testimony.



Employers should also mitigate the risk of retaliation. Both the EEOC and the Department of Labor state that employers cannot retaliate against employees for protected activity.

Step Five: Reach a Conclusion and Take Appropriate Action

At the end of the investigation, the employer should determine whether the evidence supports a finding that misconduct occurred or that a policy was violated. Employers often make a workplace decision based on the information reasonably available to them.

The final documentation should generally identify the concern investigated, the witnesses interviewed, the evidence reviewed, the factual findings, any credibility considerations, whether the allegation was substantiated, and any recommended corrective action.

If misconduct occurred, the employers should take corrective action that is prompt, proportionate, and consistent with how similar issues have been handled. Corrective action may include coaching, training, a written warning, reassignment, schedule changes, suspension, demotion, termination, policy revisions, or broader workplace training.

The response should be tied to the facts, the severity of the conduct, the employee's history, and the employer's policies.

The Bottom Line

The strongest investigations are prompt, impartial, well-documented, and focused on facts. Employers should have a clear process before a complaint arises, train managers to recognize when concerns must be escalated, and take each workplace concern seriously from the beginning.