I'll admit to not having done the research yet.

Parolee makes a threat to kill his Parole Officer, because PO is revoking parole. Threat is made at a State Hospital, where parolee had admitted himself. Parolee goes from State Hospital to County Jail (Blue Warrant.)

Is this retaliation?

RETALIATION: A person commits an offense if he intentionally or knowingly harms or threatens to harm another by an unlawful act1) in retaliation for or on account of the service or status of another as aA) public servant, witness, prospective witness, or informant

I think retaliation fits because he has 'threatened' to harm another with an unlawul act in response to the PO filing to revoke him which is the PO's service provided. The PO fits for public servant and witness in (1)(A).

I think it'll go.

WTO, use spaces between your : and your ( and you won't get

Case law supports it. Moore v. State, 143sw3d305 (Waco-Yeah, I know Waco.) and Doyle v. State, 661 SW2d 726 (CCA)