While a criminal conviction requires proof beyond a reasonable doubt, the slayer rule applies to civil law, not criminal law, so the petitioner must only prove the murder by a preponderance of the evidence, as in a wrongful death claim meaning on the civil standard of proof of the balance of probability.
[1] In Mutual Life v. Armstrong (1886), the first American case to consider the issue of whether a slayer could profit from their crime, the US Supreme Court set forth the No Profit theory (the term "No Profit" was coined by legal scholar Adam D. Hansen in an effort to distinguish early common law cases that applied a similar outcome when dealing with slayers),[1] a public policy justification of slayer statutes: "It would be a reproach to the jurisprudence of the country if one could recover insurance money payable on the death of the party whose life he had feloniously taken.
[1] The Strict Construction theory (the term "Strict Construction" was coined by legal scholar Adam D. Hansen in an effort to distinguish early common law cases that dealt applied a similar outcome when disinheriting slayers)[1] originated from Judge John Clinton Gray's dissent in Riggs v. Palmer (1889).
In Judge Gray's opinion, the court could not simply create or imagine such statutes so as to obtain a morally pleasing result.
Such an action is brought by a successor, or other party of interest (e.g., life insurance company, bank), on behalf of the victim's estate.
[4] In 1936, legal scholar John W. Wade proposed a No Profit theory statutory fix to promote uniformity amongst the states in dealing with slayer cases.
[6] Forty-eight states have enacted laws that strip a slayer of any inheritance benefit he would have gained from his unlawful act.
Several specific cases (e.g., Grace Pianka;[10] Douglas Grant;[11][12][13] and Gilbert Ramos)[14] prompted the Arizona legislature to amend Arizona's slayer rule by 1) expressly defining “intentional and felonious” to mean any individual who is found guilty of murder in the first or second degree, or the lesser crime of manslaughter; 2) allowing victims to place the decedent's estate in constructive trust immediately from the time of the killing; and 3) allowing the victims to place the slayer's estate (i.e., life insurance benefits) in constructive trust, in the case of murder-suicide.
The Florida slayer rule prevents a murderer receiving the benefits they would otherwise be entitled to by the terms of the victim's will itself or by statute.
[21] The court's holding relied on the Model Probate Code and several jurisdictions favoring the contingent beneficiaries, and assuming the victim would disfavor the children of the slayer would call for "inappropriate speculation.