In what circumstances will a jury be unable to disregard evidence that a defendant has admitted to a previous crime even if they have been instructed to do so?

In support of his contention that the jury's receipt of extra-record information about the possible meaning of his tattoo was incurably prejudicial, Wynn relies on several cases for the proposition that "[i]t is well-recognized that jury admonitions to disregard certain matters are not always effective and realistic." Specifically, Wynn cites case law stating that jurors may not be able to disregard information that a defendant committed a previous crime or confessed to the instant crime even if instructed to do so. (People v. Navarrete (2010) 181 Cal.App.4th 828, 836 ["even a single reference to an inadmissible confession can be the sort of 'exceptional circumstance' that supports granting a mistrial because a curative instruction cannot undo the prejudice to the defendant"]; People v. Gibson (1976) 56 Cal.App.3d 119, 130 [jury could not be expected to disregard other-crimes evidence admitted against the defendant].)