Page "Confidentiality" Paragraph 7

Note that these exceptions generally do not cover crimes that have already occurred, even in extreme cases where murderers have confessed the location of missing bodies to their lawyers but the police are still looking for those bodies.

The U. S. Supreme Court and many state supreme courts have affirmed the right of a lawyer to withhold information in such situations.

Otherwise, it would be impossible for any criminal defendant to obtain a zealous defense.