Interrogating is one thing, spotting the lie (or the inconsistency that leads to spotting the lie) is another skill entirely. I have a colleague that is scarily good at this.
I am fairly intelligent, and consider myself emphatic and not unintelligent emotionally, but I just can't spot lies. By default I assume people are telling the truth and can't seem to override this setting in my brain.
There's an entire industry peddling pseudoscience around it but there's basically no evidence that it works.
See this recent Skeptoid for a good summary: https://skeptoid.com/episodes/4836
That episode quotes an opinion paper in Frontiers in Psychology, which I'll also do here:
> Is the rational course simply to drop this line of research? ...We have now sufficient evidence that there are no specific non-verbal behavioral signals that accompany lying or deceitful behavior. We can safely recommend that courts disregard such behavioral signals when appraising the credibility of victims, witnesses, and suspected offenders. For psychology and law researchers it may be time to move on.
On the theory of Skin In The Game: instead of doing these experiments like this, I would find a consistently winning poker player. Or a cop who's consistently caught suspects in lies. That is, people who've shown that they can detect lies.
It might be that they can't even tell you what they do. Even worse, maybe they fail in these artificial experiments. I'd still hire the cop who's succeeded at it.