GENERAL PART
Aim of the Criminal Code
Chapter III
Obstacles of Criminal Prosecution
Title I
Grounds for the Preclusion of Punishability
Error
Section 27
(1) The perpetrator shall not be punishable for a fact, of which he was not aware on perpetration.
(2) The person, who commits an act in the erroneous hypothesis that it is not dangerous for society and who has reasonable ground for this hypothesis, shall not be punishable.
(3) Error shall not exclude punishability, if it is caused by negligence, and the law also punishes perpetration deriving from negligence.
Mistake of fact - national proceedings
EDIT.