What is the test for an offer of a more lenient sentence in exchange for a guilty plea?

A court may not chill a defendant's exercise of his constitutional right to trial either by offering a more lenient sentence in return for a guilty plea than the court would impose following a trial, or by imposing a more severe sentence because the defendant elects to go to trial. (Lewallen, supra, 23 Cal.3d 274 at p. 281.) However, the mere fact that the defendant received a more severe sentence after trial than he was offered before trial is not enough to support an inference that he was penalized for exercising his constitutional rights. (People v. Szeto (1981) 29 Cal.3d 20, 35.) The court may legitimately impose a more severe sentence after trial if the evidence at trial reveals more adverse information about the defendant than was known at the time the offer was made.

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