The principle of "no prosecution in case of doubt" means that in criminal proceedings, the procuratorial organ should make a decision not to prosecute if the criminal facts are unclear, the evidence is unreliable and insufficient, and the criminal suspect should not be investigated for criminal responsibility.
article 173 of the criminal procedure law if a criminal suspect has no criminal facts, or is under any of the circumstances specified in article 15 of this law, the people's procuratorate shall make a decision not to prosecute.