5 C.F.R. § 1651.12
If the participant's death is the result of a homicide, a beneficiary will not be paid as long as the beneficiary is under investigation by local, state or Federal law enforcement authorities as a suspect. If the beneficiary is implicated in the death of the participant and the beneficiary would be precluded from inheriting under state law, the beneficiary will not be entitled to receive any portion of the participant's account. The TSP record keeper will follow the state law of the participant's domicile as that law is set forth in a civil court judgment (that, under the law of the state, would protect the TSP record keeper from double liability or payment) or, in the absence of such a judgment, will apply state law to the facts after all criminal appeals are exhausted. The TSP record keeper will treat the beneficiary as if he or she predeceased the participant and the account will be paid in accordance with § 1651.10 .
5 C.F.R. §1651.12