As used in this chapter: “Decedent” means any person whose life has been taken as a result of murder or voluntary manslaughter. “Property” includes any real and personal property and any right or interest therein. “Slayer” means any person (i) who is convicted of the murder or voluntary manslaughter of the decedent or, (ii) in the absence of such conviction, who is determined, whether before or after his death, by a court of appropriate jurisdiction by a preponderance of the evidence to have committed one of the offenses listed in clause (i) resulting in the death of the decedent. For the purposes of clause (ii), the party seeking to establish that a decedent was slain by such person shall have the burden of proof.