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Understanding Workplace Investigations in California

Workplace Process 6 min read Updated 2026-03-05

Overview

When an employer receives a complaint of workplace misconduct - such as harassment, discrimination, retaliation, theft, or policy violations - California law generally requires the employer to conduct a prompt, thorough, and fair investigation. The investigation process serves multiple purposes: it helps the employer determine what happened, enables appropriate corrective action, and demonstrates the employer's commitment to maintaining a lawful workplace.

Workplace investigations are governed by a combination of statutory requirements, case law, and practical best practices. The quality of an investigation can significantly affect the outcome of any subsequent legal proceeding.

This guide provides a general overview of workplace investigations in California. It does not constitute legal advice.

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When Is an Investigation Required?

California courts and regulatory agencies have established that an employer has a duty to investigate when it receives a complaint of unlawful conduct or otherwise becomes aware of facts suggesting that a violation may have occurred. The duty arises most clearly in the following contexts:

Harassment and Discrimination

Under FEHA, employers are required to take all reasonable steps to prevent harassment and discrimination. When a complaint is received - whether formal or informal, written or verbal - the employer is generally expected to investigate. In Cotran v. Rollins Hudig Hall International, Inc. (1998) 17 Cal.4th 93, the California Supreme Court emphasized the importance of a fair investigation process.

Retaliation

Complaints of retaliation should also trigger an investigation, particularly when the employee alleges that adverse action was taken in response to a protected activity.

Wage and Hour Complaints

While the investigation process for wage and hour complaints may differ procedurally, employers who receive internal complaints about unpaid wages or other Labor Code violations are well-served by investigating the allegations.

Other Misconduct

Employers may also conduct investigations into allegations of workplace violence, theft, substance abuse, safety violations, or other policy violations. While the legal framework may differ, the general principles of a fair and thorough investigation apply.

Key Principles of a Fair Investigation

California case law and regulatory guidance establish several principles that govern workplace investigations:

Promptness

The investigation should begin as soon as practicable after the complaint is received. Unnecessary delays can undermine the investigation's credibility and may expose the employer to liability.

Thoroughness

The investigation should be full enough to address the allegations. This generally includes interviewing the complainant, the accused, and relevant witnesses; reviewing documentary evidence (such as emails, text messages, and personnel records); and considering all relevant information.

Objectivity

The investigator should approach the investigation without bias or a predetermined outcome. The investigator should not be someone who has a personal interest in the outcome or a close relationship with the parties involved.

Confidentiality

The employer should maintain confidentiality to the extent possible, while explaining to participants that absolute confidentiality cannot be guaranteed (for example, information may need to be disclosed to take corrective action or in connection with legal proceedings).

Documentation

The investigation and its findings should be documented in writing. A thorough investigation report typically includes a summary of the allegations, a description of the evidence reviewed and witnesses interviewed, findings of fact, and conclusions regarding whether the alleged conduct occurred and whether it violated the employer's policies or the law.

The Investigation Process

While the specific process varies depending on the nature of the allegations and the employer's resources, a workplace investigation generally follows these steps:

1. Receipt of the Complaint

The process begins when the employer receives a complaint or otherwise becomes aware of potential misconduct. The complaint may come from the affected employee, a witness, a manager, or another source.

2. Selection of an Investigator

The employer should select an investigator who is impartial, experienced, and has no conflict of interest. The investigator may be an internal employee (such as an HR professional) or an external investigator retained for the purpose.

3. Planning the Investigation

Before conducting interviews, the investigator should develop a plan that identifies the key issues, the relevant witnesses, and the documentary evidence to be reviewed.

4. Interim Measures

Depending on the severity of the allegations, the employer may need to take interim measures to protect the complainant during the investigation. These may include separating the parties, adjusting schedules, or placing the accused on administrative leave. Interim measures should not penalize the complainant.

5. Interviews

The investigator typically interviews:

  • The complainant. To understand the allegations in detail, including who was involved, when and where the conduct occurred, and what evidence exists.
  • The accused (respondent). To provide the respondent with an opportunity to respond to the allegations.
  • Witnesses. To gather information from individuals who may have observed the alleged conduct or have relevant knowledge.

All interviews should be documented, and participants should be informed that retaliation is prohibited.

6. Document Review

The investigator should review relevant documents, including emails, text messages, personnel files, performance evaluations, prior complaints, and any other records that may be pertinent.

7. Credibility Assessments

When the accounts of the complainant and the respondent conflict - which is common - the investigator must make credibility determinations. Relevant factors may include consistency of each party's account, corroborating or contradicting evidence, demeanor during the interview, motive, and any prior history of similar complaints.

8. Findings and Conclusions

The investigator should reach conclusions based on the evidence gathered. In employment investigations, the standard of proof is generally preponderance of the evidence - meaning the investigator determines whether the alleged conduct more likely than not occurred.

9. Corrective Action

If the investigation confirms that misconduct occurred, the employer is expected to take appropriate corrective action. The corrective action is generally proportionate to the severity of the misconduct and designed to prevent recurrence. Corrective actions may include counseling, training, written warnings, suspension, demotion, or termination.

10. Follow-Up

After corrective action is taken, the employer should follow up with the complainant to ensure the conduct has stopped and that no retaliation has occurred.

The Cotran Standard

In Cotran v. Rollins Hudig Hall International, Inc. (1998) 17 Cal.4th 93, the California Supreme Court held that an employer's good-faith decision to terminate an employee based on the results of a fair investigation is not subject to second-guessing by a jury - even if the jury might have reached a different conclusion. Under the Cotran standard, the question is whether the employer acted in good faith and had reasonable grounds for believing the employee engaged in misconduct, based on a fair and honest investigation.

This standard underscores the importance of conducting a thorough and fair investigation before making employment decisions.

Employee Rights During an Investigation

Employees who are the subject of or participate in a workplace investigation have certain rights and protections:

  • Protection from retaliation. It is unlawful for an employer to retaliate against an employee for filing a complaint, participating in an investigation, or cooperating with an investigation.
  • Right to a fair process. While employees do not have a constitutional right to due process in private employment (as they may in public employment), the investigation should be conducted fairly and in good faith.
  • Weingarten rights (unionized workplaces). In unionized workplaces, employees may have the right to have a union representative present during investigatory interviews that the employee reasonably believes could lead to disciplinary action.

External Investigations

In addition to internal investigations, workplace complaints may trigger investigations by external agencies, including:

  • The CRD (for FEHA complaints)
  • The EEOC (for federal discrimination complaints)
  • The DLSE/Labor Commissioner (for wage and hour complaints)
  • Cal/OSHA (for workplace safety complaints)

Employers should cooperate with agency investigations and maintain records related to internal investigations in anticipation of potential external inquiries.

Conclusion

Workplace investigations are a critical component of employment law compliance in California. A prompt, thorough, and fair investigation protects both the employer and the employees involved. The legal standards governing investigations are well-established but require careful application to the specific facts of each case. Employers who need to conduct investigations - and employees who are involved in them - are encouraged to consult with a qualified employment law attorney.

This guide is provided for general informational and educational purposes only. It does not constitute legal advice, and no attorney-client relationship is created by reading this material. Laws and regulations may change, and the application of law depends on the specific facts of each situation. Consult a qualified attorney for advice regarding your particular circumstances.

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Important Disclaimer: This guide is for general informational and educational purposes only and does not constitute legal advice. No attorney-client relationship is created by reading this guide. Employment law is constantly evolving - statutes are amended, new regulations are adopted, and court decisions can change the interpretation of existing law at any time. While we strive to keep this guide accurate, we cannot guarantee that all information reflects the most current state of the law. This guide may not address recent legislative changes, pending regulations, or new case law that could affect your rights or obligations. Every situation is unique. If you need legal advice about your specific situation, please consult a qualified California employment attorney. Do not rely on this guide as a substitute for professional legal counsel.
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