The ICC does not have enough checks on prosecutorial powers, inviting prosecutorial abuse.  The issues the ICC deals with are inherently subjective, as there is clear disagreement about what counts as a war crime or what the exact definition of genocide is. This leaves dangerous room for the prosecutor to simply decide what he thinks counts as a crime under the statute. Under the Rome Statute, the prosecutor has the power to both initiate an investigation based on reasonable evidence (of which there are no clear standards for outlined in the Rome Statute) and refuse to follow up on an investigation in the name of "justice." There are no clear higher checks on the prosecutor, putting too much power in the hands of one single individual. Additionally, there is very limited judicial review, as the pre-trial chamber is composed of 1 or 3 judges, and the prosecutor is able to find a judge who is sympathetic to his views.1  1 Rubin, Alfred P. "The International Criminal Court: Possibilities for Prosecutorial Abuse." Law and Contemporary Problems, Vol. 64 No. 1, Winter 2001, 153-165.