The problem with most of these suggestions is that they are just fantasy solutions. This guy seems to thrive on litigation and there is no reason to believe if your mom just throws him out that he won't turn around and sue her. She will win in the end, but it will cost her money. The only practical solution I have seen here so far is to get a restraining order against him.
The only other practical solution is to just change the locks on the doors. While he could sue for an illegal eviction, the fact that he did a stop payment on the check is evidence that he breached the lease contract so his allegations would just be a wash. Make sure your mom has physical evidence of the stop payment.
Oh and I am one of those scum bag attorneys that no one has any used for.
