When facilitating an incident investigation, part of the job is talking to people to figure out what really happened. Unfortunately, not everyone you speak to is going to give you the full truth. Some might forget key details by mistake, but others may twist the facts or even outright lie. After all, investigations usually start when something doesn’t go well, and people often want to protect their jobs and reputations.
There’s plenty of material out there about the psychological drivers of dishonesty. But as an engineer, I’m more interested in finding realistic solutions for uncovering the truth. When I suspect someone isn’t being truthful, I don’t try to read their mind. Instead, I use these practical tactics to keep the investigation on track.
Refresh the Person’s Memory
When I encounter possible deceit, the first step I take is to help the person refresh their memory. I’ll ask them to review their previous statement if they gave one. If there are any video recordings, I’ll have them watch those as well. Walking through the physical evidence together can also jog the person’s memory. Visiting the actual location is ideal, but if that’s not possible, you can review photos. Another helpful tactic is to ask the person to draw a diagram so that you have an exact understanding of their proximity to the events.
Taking the time to walk through the event can lead people to reveal more than they initially intended. For example, a leak from a hose may be portrayed as a “drip” with a minor quantity leaked. When you visit the field, you realize the residue marks on the concrete cover quite a large surface area prompting you to measure the area and do a volume calculation. Then you discover the hose that was used did not have a gasket in it, and it never even occurred to the person that connected the hose to check for the gasket.
Use Visuals to Clarify
A lie isn’t always easy to spot, especially when it’s buried in a long-winded story. When I suspect lies might be hidden within someone’s narrative, I use visual tools to clarify. One visual tool is a process map, which I’ll build by asking the person to talk through the steps they took in the context of the incident. The other is a Cause Map™ diagram, which I’ll build out by following the person’s explanation of what caused what. I always have these visuals available during discussions, because they help keep the focus on building an accurate map—not pointing fingers. This helps lower defenses, as it becomes less about the person and more about understanding what happened.
Showing these visuals to the person is often enough for them to realize that their story isn’t adding up. If necessary, you can share your diagrams with the group to confirm whether the person isn’t being truthful. When you share with the group, you don’t have to call out the person you think is being deceitful. In fact, it’s often better to not do that. Instead of saying, “This is what Joe said,” say, “This is how someone described what happened—does this look accurate?”
Get Specific—And Don’t Be Afraid to Ask “Stupid Questions”
One of the most effective ways to obscure the truth is to use technical jargon. For example, has anyone ever told you that there was “steel in the line?" The person who used this phrase when talking to me did not mean a weld or a blind. What they really meant was that a valve was closed. Perhaps it was intentionally deceitful, or maybe it was just operations everyday jargon. Either way, this language wasn’t a very clear way to explain what was happening.
Don’t be afraid to ask clarifying questions about technical details and terminology. When I don’t understand what someone is telling me, I’ll ask specific, yet open-ended questions such as “Can you explain to me how that coupling works?” Asking “how” questions is useful because it encourages people to think through things in smaller steps, helping to clarify how one cause produces an effect. If I still don’t understand, I’ll ask the person to draw me a diagram. I may also pull in an independent expert to verify technical details.
It’s also important to be mindful of your own assumptions. Check that you’re not using obtuse terminology or making logical leaps based on your own technical know-how. The more specific the details, the harder it is for misunderstanding to slip through.
Manage Relationships
Managing relationships is key to uncovering the truth in an investigation. Start by understanding the group dynamics at play. Reporting relationships certainly influence what people are willing to say. Most folks won’t speak freely if someone in the room has the power to fire them. But it’s also important to be attentive to informal dynamics such as who’s well-liked or feared. Observe how behavior shifts depending on who’s present.
Next, navigate those relationships carefully. Work with individuals or small groups before engaging with the larger group. When you do get the larger group together, keep the focus on finding solutions—not assigning blame. Credibility with the people doing the work is key. If you don’t have a good relationship with those involved in the incident, they’ll be less likely to be honest with you. Start building trust now, so that if incidents arise, they’ll know you personally and be more open.
This approach is especially vital when human error is involved. Remind everyone that all humans make mistakes. The purpose of the investigation is to understand how to lower the risk of the next person making the same mistake.
Focus on the Facts and Keep Moving Forward
Lying is bad—but it sure is fun to think about. That’s why so many movies and TV shows follow the same formula: the bad guy spins a web of deceit, the good guy uncovers the truth, with tons of juicy drama in between.
But in real-life investigations, we don’t have time for dramatic plot twists. A facilitator’s job isn’t to expose villains—it’s to find solutions that help prevent future problems. By digging into the details, using visuals, and asking clarifying questions, you can keep the investigation moving forward.
