When will the prosecution use a prior manslaughter conviction to impeach appellant's testimony on a charge relating to possession of a concealable firearm?

Prior to trial, appellant made a "Beagle" motion (People v. Beagle (1972) 6 Cal.3d 441, 99 Cal.Rptr. 313, 492 P.2d 1) to exclude the prior manslaughter conviction. The prosecution argued that Proposition 8 ⁴ essentially overturned the balancing process mandated by Beagle. ⁵ The trial court agreed and allowed the prosecution to use the prior manslaughter conviction to impeach appellant's testimony on all charges, including the possession of a concealable firearm charge, which offense occurred before the effective date of Proposition 8.