Originally Posted By: TheFallibleFiend
Particularly if the person knows the accusation is false, he is a
Slanderer / Libeler / Defamer
Calumniator

If the accuser is himself guilty of the accusation, then he may also be a hypocrite.


I would reject all these since blaming others is not a necessary part of any of these. They may be true about the person in question but they do not define them.