Falsus In Uno Doctrine Law and Legal Definition

Falsus In Uno Doctrine refers to a principle that that if the jury believes that a witness's testimony on a material issue is intentionally deceitful, the jury may disregard all of that witness's testimony. This comes from the maxim ‘falsus in uno, falsus in omnibus’ which means false in one thing, false in all. This is recognized by many courts in their charges to the jury.