TL;DR: Credibility calls are non-negotiable in workplace investigations. Use a five-factor test—plausibility, corroboration, consistency, prior incidents and motive—to reach a defensible, more-likely-than-not conclusion and document every step.
Three Main Takeaways from the Video
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Credibility Is Essential, Not Optional
The standard is “more likely than not,” so investigators must decide whose account is believable instead of defaulting to inconclusive. -
You Already Have the Skill Set
Every day HR tasks like interviewing and performance reviews hone the judgment needed to assess truthfulness—apply those instincts deliberately during investigations. -
Follow a Structured Five-Factor Test
Evaluate plausibility, corroboration, consistency, prior incidents and motive, then document the reasoning to control bias and protect the organization.
Video Transcript
Rather read than watch? Here’s the video transcript:
[0:00] Hi everyone, I’m Deb Muller, and today we’re talking about something investigators often shy away from but can’t afford to avoid: credibility assessments. Now, I get it—you’re knee deep in an investigation, and the stories don’t line up. The complainant says one thing, the accused says the opposite, and you can find yourself in the dreaded he-said-she-said spiral. That little voice pops up: “How am I supposed to know who’s telling the truth?” Well, here’s how you assess credibility. It’s not optional; it’s part of your job.
This is a workplace investigation, not a criminal trial. You’re not proving guilt beyond a reasonable doubt. You’re determining whether it’s more likely than not—even by just a fraction—that something happened. That’s a 50.1 percent standard. Credibility, when done right, can anchor your findings and help you cross that line with confidence.
[1:05] I’ve heard this excuse a hundred times: “I’m not qualified to make an assessment on credibility.” My response? Yes, you are. You’ve done it before, probably just this week. Most of us in ER came up through HR roles where we were constantly assessing people—making hiring decisions, evaluating performance, sitting in interviews and thinking, “H that answer felt rehearsed,” or, “She didn’t make eye contact,” or, “That story just didn’t add up.” Sound familiar? That’s credibility assessment. You’ve got the skills; now apply them to your investigations.
[1:35] Let me give you five things to look for when assessing credibility.
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Plausibility – Does a story make sense given what you know? Is the explanation logical or does it stretch belief?
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Corroboration – Back it up. Are there emails, texts, badge data or witnesses that support or contradict the account? Look beyond what was said to find what you can prove or disprove.
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Consistency – Are the details stable over time? Sure, memories fade but wild inconsistencies can be a red flag.
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Prior incidents – Patterns matter. Does this behavior align with past issues? Has this come up before formally or informally?
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Motive – Ask yourself: Is there a reason someone might not be fully honest with you? That includes the complainant, the subject and even witnesses.
[2:25] While we’re on honesty, check yourself—investigator bias is real. Maybe you know the manager involved. Maybe there’s pressure to wrap things up really quickly. Recognize it and control for it.
[2:45] When I first wrote about credibility over a decade ago, I kept coming back to one question to ask yourself: How do I know? That’s the bar whether it’s a hiring decision, a behavior issue or a misconduct investigation. If you can’t answer how you know then your decision isn’t defensible. So document your process, write a strong report and most importantly make the call. Don’t default to “inconclusive” just because it’s easier. Credibility assessments are not about gut feelings; they’re about structured thoughtful judgment. When you do it right, you’re not guessing—you’re leading.
Thanks for watching, and if you’ve got a go-to method for assessing credibility in tough cases, drop it in the comments. I’d love to hear how you know.
