One Word. A person that falsely, without valid proof, accuses you of something, such as a statement or act you said or did. Either because of his lack of knowledge about the proof or because of intent.
To falsely accuse to deflect attention away from yourself onto another is to frame them. The person would be a framer.
: to devise falsely (as a criminal charge)
: to contrive the evidence against (an innocent person) so that a verdict of guilty is assured
You could say that the person was fabricating a plan against you too. The person would be a fabricator.
someone who tells lies
invent or concoct (something), typically with deceitful intent.
And the following usually work too. Since someone accusing you of doing something you didn't is damaging your reputation.
charge falsely or with malicious intent; attack the good name and reputation of someone
In the right situation the following work too:
- Slanderer - someone who deliberately tells lies that will damage your reputation
- Libeller - slandering in print
- Perjurer - slandering under oath, or other specific legal circumstances
Of course, liar covers all these and more.
Famacide (a killer of reputation) is a nice one too.
Although not one word, you could have fun combining more than one of the above.
"You devious famacidal slanderer!" cursed Marie as the angry mob turned their back on her twin sister and turned their weapons on her instead.
However, if with deliberate intent to harm or ruin another's reputation, they are referred to as calumniators.
Libeller - one who accuses falsely and maliciously, or publishes any false and defamatory statement in conversation or otherwise.
From the OED:
One who libels another; one who publishes a libel or libels.
From the OED a definition of the verb libel is:
To defame or discredit by the circulation of libellous statements; to accuse falsely and maliciously
And a definition of the noun libel is:
In popular use: Any false and defamatory statement in conversation or otherwise.
Delator is a professional accuser
to blame (someone) for something wrong or illegal : to say that someone is guilty of a fault or crime