With respect to the critical facts of the case—whether the crime charged was committed and whether the defendant was the person who committed the crime—the state has the entire burden of proof.
With respect to the critical facts of the case, the defendant does not have any burden of proof whatsoever. The defendant does not have to testify, call witnesses or present any other evidence, and if the defendant elects not to testify or present evidence, this decision cannot be used against them.