29 CFR 18.410 - Inadmissibility of pleas, plea discussion, and related statements.
Except as otherwise provided in this rule, evidence of the following is not admissible against the defendant who made the plea or was a participant in the plea discussions:
(a) A plea of guilty which was later withdrawn;
(b) A plea of nolo contendere;
(c) Any statement made in the course of any proceedings under Rule 11 of the Federal Rules of Criminal Procedure or comparable state procedure regarding either of the foregoing pleas; or
(d) Any statement made in the course of plea discussions with an attorney for the prosecuting authority which do not result in a plea of guilty or which result in a plea of guilty later withdrawn. However, such a statement is admissible in any proceeding wherein another statement made in the course of the same plea discussions has been introduced and the statement ought in fairness be considered contemporaneously with it.