Actually, all states except Montana follow the “at will" clause meaning you can terminate an employee for any reason or he or she can quit for any reason without either offering an explanation. In Montana, you must offer “just cause" as to why you fired the employee and be able to prove it—here’s where a coworker witness would help, especially if your business is in Montana.
There are other rules, both on the federal and state levels, that protect employees from termination. When it comes to termination for lying, some states enforce employment contracts and protect government and union workers. What this means if your employee has a signed employment contract listing the reasons you can terminate or they can quit, and lying isn’t one of the reasons, chances are if the case goes to court, the judge will lean toward the employment contract.
So, what’s left for employers to do with a lying employee without fear of the treat of a lawsuit? No business owner wants to be on the losing side of an employee lawsuit, but they often are.
What you must do is investigate, verify, and provided written warnings before you terminate. Again, while accusing anyone of lying is problematic, if you don’t have certain processes in place, chances of your winning a wrongful termination lawsuit are slim. Follow these steps below on how to fire a lying employee.