Does the risk of tainting the trial irreparably outweigh the fact that the trial court informed the jury of appellant's rape and sexual assault convictions without knowing whether they would ever be introduced in the case?

We note, moreover, that the trial court informed the jury of appellant's rape and sexual assault convictions without knowing whether they would ever actually be introduced in the case--and as it turned out, they never were. The possibility that the convictions might have been introduced in a collateral manner at some later stage, and then only after their prejudicial value had been balanced against the probative, was simply not weighty enough to justify "the risk of tainting the trial irreparably." United States v. Collatos, 798 F.2d 18, 21 (1st Cir.1986).