Protecting Attorney-Client Privilege During a Workplace Investigation in California

A complaint lands on your desk. Harassment, discrimination, retaliation, it doesn't matter which. Your first instinct is to get answers fast. But if you skip a few key steps before you start asking questions, you could lose the one protection that keeps your investigation notes, interview summaries, and internal findings out of a plaintiff's hands later.

That protection is attorney-client privilege, and it does not attach automatically just because a lawyer is somewhere in the loop.

In summary: Attorney-client privilege protects a workplace investigation in California when the investigation is directed by an attorney for the dominant purpose of providing legal advice, not simply to gather business facts. If an HR manager runs the investigation without counsel's direction, or if the attorney is functioning as a neutral fact-finder rather than legal advisor, the privilege likely will not apply, and everything produced during the investigation could become discoverable in litigation.

Why Privilege Matters So Much in a Workplace Investigation

Every internal investigation creates a paper trail: interview notes, witness statements, timelines, credibility assessments, and a final report. If a lawsuit follows, opposing counsel will want every page of it. Without privilege protection, they can usually get it.

That is a serious problem. Investigation notes often contain candid witness impressions, preliminary conclusions, and internal debate about what actually happened. Handed over in discovery, those materials can hand the other side a roadmap of your weaknesses. A properly privileged investigation, by contrast, lets your defense attorney control what gets disclosed and when.

The Legal Standard: What California Courts Actually Look At

California follows a "dominant purpose" test to decide whether a communication during an investigation is privileged. Courts ask whether the attorney's central role was to deliver legal advice, or whether the attorney (or investigator working for the attorney) was simply performing a business function that any HR professional could have handled.

This distinction traces back to the U.S. Supreme Court's decision in Upjohn Co. v. United States, which extended corporate attorney-client privilege beyond a company's small executive "control group" to cover rank-and-file employees speaking with counsel at the direction of management. California courts have applied a similar, though narrower, framework. The key question is always the same: was the investigation conducted to secure legal advice for the company, or just to figure out what happened?

If an attorney is hired purely as a neutral, independent fact-finder, with no expectation of giving legal advice, courts have found that the resulting report is not privileged. The label "attorney" attached to the investigator's name is not enough. What matters is the actual function performed.

Steps That Help Preserve Privilege

There is no guarantee that any investigation will survive a privilege challenge intact, but a few practices consistently strengthen the case for protection.

Engage counsel before the investigation starts, not after a lawsuit is already threatened. When outside or in-house counsel directs the investigation from the beginning, and clearly frames the work as being done to render legal advice, courts have a much easier time finding privilege applies. This is one of the biggest reasons employers work with a workplace investigator who reports directly to legal counsel rather than to HR alone.

Give every witness an Upjohn warning at the start of their interview. This means telling the employee that the attorney represents the company, not them individually, that the conversation is confidential, and that the privilege belongs to the company, which may choose to waive it later. Skipping this step has undone privilege claims in real litigation.

Mark investigation materials clearly. Notes, memos, and draft reports should be labeled "Attorney-Client Privileged" and "Attorney Work Product" where appropriate. Labels alone don't create privilege, but sloppy handling of unmarked documents makes it far easier for opposing counsel to argue the materials were never treated as confidential.

Limit distribution. Only people with a genuine need to know should see investigation materials. Sharing the report widely inside the company, or discussing findings casually outside the privileged group, can waive protection even if everything else was done correctly.

Separate legal advice from business decisions. If the investigation report blends factual findings with legal analysis and recommended discipline, keep the legal reasoning distinct. Courts sometimes require disclosure of pure fact-finding portions while allowing legal analysis to remain protected.

When Privilege Gets Waived Anyway

Even a well-run investigation can lose its privilege protection. This most often happens when a company later relies on the investigation itself as a defense, for example, arguing in litigation that it conducted a thorough, good-faith investigation before taking disciplinary action. Once you put the adequacy of the investigation at issue, courts often require you to produce the underlying materials so the other side can test that claim.

Voluntary disclosure to a third party, such as turning over the report to a government agency or an insurance carrier, can also waive privilege. This doesn't mean employers should never share investigation findings. It means the decision to disclose should be made deliberately, with legal counsel weighing the tradeoffs, not as an afterthought.

Getting Investigations Right From the Start

The businesses that come out of workplace investigations in the strongest legal position are the ones that treat privilege as part of the plan from day one, not a problem to sort out after a complaint escalates. That means looping in your employer defense attorney before the first interview, choosing the right investigator for the situation, and following a consistent, documented process every time.

Brereton, Mohamed, & Korte LLP works with California employers to structure workplace investigations that hold up under scrutiny, protect the privilege where it applies, and give businesses a defensible record if the matter ever turns into litigation. If you're facing a complaint or want to strengthen your investigation process before one arrives, our employer defense team can help you build a plan that fits your business. If the investigation ultimately leads to a separation, our attorneys can also advise on wrongful termination defense so your decision holds up if challenged.

Don't wait for a subpoena to find out whether your investigation was privileged. Contact Brereton, Mohamed, & Korte LLP today to talk through your process before your next complaint arrives.

Frequently Asked Questions

Q: Does attorney-client privilege automatically apply just because a lawyer runs the investigation?

 A: No. California courts look at the dominant purpose of the investigation, not just who conducted it. If the attorney is acting as a neutral fact-finder rather than providing legal advice, the privilege likely will not apply.

Q: Can our HR team conduct the investigation, or do we need an outside investigator?

 A: HR can handle many complaints, but investigations involving senior leadership, high litigation risk, or a perceived conflict of interest are usually better handled by an outside neutral working under attorney direction to preserve privilege where possible.

Q: What is an Upjohn warning and why does it matter?

 A: It's a notice given to employees at the start of an interview explaining that the attorney represents the company, that the conversation is confidential, and that the privilege belongs to the company, not the individual employee. Skipping it can undermine a privilege claim later.

Q: What happens if we later rely on the investigation as a legal defense?

 A: Using the investigation to argue you acted reasonably or in good faith often waives privilege over the underlying materials, since you've put the investigation's adequacy at issue. This tradeoff should be discussed with an employer defense attorney before it happens.

Q: Can sharing the investigation report with our insurance carrier waive privilege?

 A: It can. Voluntary disclosure to a third party outside the privileged group risks waiver, so any decision to share findings should be made deliberately with legal counsel involved.

Q: What standard of proof applies during a California workplace investigation?

A: Investigators use a "more likely than not" standard, not the criminal "beyond a reasonable doubt" standard. Applying the wrong standard is a common employer mistake that can undercut appropriate corrective action.

Q: When should we bring in an employer defense attorney for a workplace investigation?

A: As early as possible, ideally before the first witness interview. Involving counsel from the outset gives you the best chance of preserving privilege and building a defensible, well-documented record if the matter later turns into litigation.