Does the rule of inadmissibility apply to any statements made during the course of a plea bargaining negotiations, such as "admissions of guilty and offers to plead guilty"?

While section 1192.4 and Evidence Code section 1153 do not expressly extend that rule of inadmissibility to any statements made during plea negotiations other than pleas of guilty and offers to plead guilty, we did so in People v. Tanner (1975) 45 Cal.App.3d 345, 119 Cal.Rptr. 407. There, a criminal defendant had written letters to the district attorney and to the deputy district attorney in charge of the defendant's case, in which he conceded that he was guilty of some involvement in the crime, but contended that his culpability was less than that of certain codefendants, and asked the prosecution to reconsider its position on a proposed plea bargain. Over the defendant's objection, the trial court allowed the People to introduce the letters as part of the prosecution's case-in-chief. (Id., at pp. 348 & 353, 119 Cal.Rptr. 407.)

On appeal, this court reversed the judgment. Because public policy favors settlements, and the chances of achieving settlements are the greatest when the defense is candid with the prosecution, we construed the rule of section 1192.4 and Evidence Code section 1153 to extend to "admissions made in the course of bona fide plea bargaining negotiations." (Tanner, at pp. 351-352, 119 Cal.Rptr. 407.) Moreover, the rule of inadmissibility applies, not merely to admissions of guilt, but also to "any incidental statements made in the course of plea negotiations...." (Id., at p. 350, 119 Cal.Rptr. 407.) That construction promotes candor, because "[t]he accused and defense counsel are assured that anything said will not be used against them if the negotiations are unsuccessful." (People v. Magana (1993) 17 Cal.App.4th 1371, 1377, 22 Cal.Rptr.2d 59.)