Where the slayer holds any interest in property, whether vested or not, subject to be divested, diminished in any way or extinguished if the decedent survives him or lives to a certain age, such interest shall be held by the slayer during his lifetime or until the decedent would have reached such age but shall then pass as if the decedent had died immediately after the death of the slayer or the reaching of such age. (1961, c. 210, s. 1.)