California, like most states, has a public policy against killers benefiting financially from their crime. That applies to estate beneficiaries seeking to profit, as well as life insurance beneficiaries. A killer cannot inherit from their victim.

In California, this common law concept is codified in Section 252 of the California Probate code:

The prohibition does not apply to justifiable homicides, such as killings in self defense. A criminal conviction for murder or voluntary manslaughter is generally conclusive in California to apply the slayer prohibition. The policy itself does not lapse. But rather the contingent beneficiary is entitled to the life insurance proceeds; and if no contingent beneficiary is designated in policy, the proceeds thereof are payable to the estate of the murdered insured.

When the life insurance company becomes aware of the possibility that the slayer prohibition applies, it will typically file an interpleader in either state or federal court in California. If you are involved in a life insurance beneficiary dispute, it is important to contact a lawyer experienced in handling such cases.