From the above, it follows that an experienced lawyer with a white collar must do a decisive job to determine if you are offering and make sure that any offer you give will be cancelled as planned. It cannot be overemphasized that your lawyer must do everything in his power to ensure that the prosecutor and the investigator know exactly what you can and cannot say at the Proffer meeting. (This is obtained by law firms and/or hypothetical interviews between the prosecutor and the defence lawyer.) Both parties must understand the terms and conditions of the proposed plea, including the likely range of the guidelines, provided the application is successful. Your lawyer must be satisfied with the reliability of the prosecutor and the knowledge and support of the procedural officer on all agreements and arrangements that have been developed with the prosecutor. Most proffers are made with informal understanding that if the government, if it is convinced that you are telling the truth at the Proffer meeting, will then conclude a formal and written immunity agreement or a plea with you. (But don`t expect this informal understanding to be reflected in the written agreement to proffer that you and your lawyer will sign. Indeed, in the vast majority of cases, the formal agreement written to proffer explicitly states that neither immunity nor pleading were made.) As a result, your lawyer and the prosecutor would have already developed informally before sitting down at the Proffer meeting, a fundamental understanding of: 1) what you are likely to offer; and 2) what the post-ad-ffer immunity or the proposed opposition agreement will look like. As you, your lawyer and the federal prosecutor, are not entirely clear about part of this informal agreement, you are heading for extremely dangerous ground. What for? Because proffering will almost always hurt you if, after immunity/advocacy, discussions fall and the government decides to charge you.
For the same reason, if the prosecutor is not trustworthy or if you are not willing to tell the full truth, the proffer meeting should never take place.