Ignorance or mistake is only a defense if it negates the specific intent required to commit an offense. A defendant’s lack of knowledge must relate to the fact that their action is illegal or against the law, rather than a misunderstanding of the law’s applicability. The key is whether the defendant’s belief was sincere and negated the criminal intent.
For example: In a case of alleged illegal hunting, if a hunter sincerely believes they are on land where hunting is permitted due to incorrect information provided by the landowner, this might negate mens rea for poaching.