State v. Smith
Superior Court of New Jersey
621 A.2d 493 (1993)
Gregory Smith (defendant), an HIV-positive inmate, repeatedly threatened to infect corrections officers by biting or spitting on them and then bit Officer Waddington hard enough to break the skin. Smith was charged with attempted murder; at trial, experts disagreed on whether HIV can actually be transmitted through a bite, and Smith testified he believed it could only spread through sex, blood transfusion, or needles. The trial judge instructed the jury it could convict if Smith intended to kill Waddington by the bite, regardless of whether transmission was medically possible; the jury convicted, and Smith appealed.
Whether impossibility — here, the medical impossibility of transmitting a fatal disease by the chosen method — is a defense to a charge of attempted murder.