When I Troubleshoot a business in which there have been complaints of theft I will often set a trap.
When possible, after Odette/Omar complains that Miss Smith is nasty or Mr.Brown tried to touch her, I’ll leave a counterfeit $10 in their room or on their desk, and monitor the incursion of Odette/Omar.
In some cases, with the assistance of the police I will have him/her stopped and searched and find that $10.
In some cases I’ll offer to sell them something valuable for $10 and be able to get that counterfeit bill.
In other cases, I’ll set a different kind of trap.
It depends on the business.
I always target those who lodge complaints about others which a normal person would not note. A normal person would not report because it is trivial or ridiculous.
When I uncover the plot, the Boss is always astounded for s/he never imagined that Odette/Omar had the brains to create such a scenario.
This is why/how they get away with it; they give the out shine of stupid loud mouths, but in reality they are conniving predators, who will steal and lie and expect to get away with it.