Defendants in criminal cases are overwhelmingly more likely to plead guilty than to go to trial. Presumably, at least a part of the reason that most of them do so is that it is in their interest to plead guilty, i.e., they will receive a more favorable outcome if they plead guilty than if they go to trial. The extent to which pleas reflect fair or rational compromises in practice, however, depends upon a variety of factors, including the amount of information each of the parties has about the case. Some level of informational symmetry therefore is critical to the plea process. Unfortunately, defendants currently have limited constitutional rights to pre-plea discovery, and prosecutors pre-plea have every incentive to conceal information that might be helpful to defendants. Further compounding the problem, prosecutors in some jurisdictions require as a condition of all pleas that defendants waive any rights they may have to pre-plea disclosures from the government. Because the failure to disclose impeachment or exculpatory information seriously undermines the accuracy and just operation of the plea process, the ethical rules governing prosecutors should be interpreted to require pre-plea disclosure of exculpatory information and impeachment information. While as a practical matter it ultimately would be up to defense counsel to guarantee that prosecutors comply with such an ethical obligation, these rules at the very least would give defense counsel a tool to obtain helpful information so that they can more accurately assess whether pleading guilty is in a client's best interest.
Hashimoto, Erica J., "Toward Ethical Plea Bargaining" (2008). Scholarly Works. Paper 819.