In Tison v. Arizona, the Tison brothers' appeal from their death sentences, the U.S. Supreme Court held that a nontriggerman convicted of first-degree felony murder could constitutionally be executed if he was a major participant in the crime and if he exhibited a reckless disregard for human life. This decision blurred the bright-line rule announced just five years earlier in Enmund v. Florida, which limited the death penalty to defendants who kill, attempt to kill, or at least intend to kill. Tison thus dramatically increased the exposure of nontriggermen to capital punishment, undercutting the death penalty's limited purpose of identifying and punishing only the most culpable killers.

In theory, Tison's standard—"major participation with reckless disregard for human life"—should expose only a limited class of nontriggermen defendants to the death penalty. However, Tyson is only part of the story; its standard does not come into play until a defendant is sentenced to death under the relevant state statute. In most states, defendants are death-eligible only if the sentencer finds one or more statutory aggravating factors. However, nearly all death penalty states use a vague and manipulable aggravating factor that singles out the murders or murderers that are somehow "worse"—more "heinous," "cruel," "atrocious," or "depraved"—than most.

In cases involving nontriggermen, the use of this manner-specific, "heinous, cruel, or depraved" aggravating factor (hereinafter "HCD") creates an intolerable, and unconstitutional, risk of arbitrary and capricious sentencing by imputing responsibility for the particularly horrific manner of killing to a defendant whose responsibility for the killing itself is attenuated. In fact, the nontriggerman convicted of felony murder is three times removed from the locus of blame: the killing is murder by reason of the felony murder rule, the defendant is responsible for the killing under accomplice liability principles, and he faces the executioner because of the manner in which another person killed. Such a defendant may be at the outer reaches of personal culpability, yet still face death.

This Note explores the peculiar confluence of the constitutional standards governing the execution of nontriggermen with those controlling the operation and construction of statutory aggravating factors. It argues that the sentencer may not constitutionally apply the HCD factor to a nontriggerman who did not intend the particular "heinous, cruel, or depraved" manner of killing. Part I provides a broad overview of death penalty jurisprudence since Furman v. Georgia and reviews the constitutional standards governing the execution of nontriggermen. Part II examines aggravating factors in general and the HCD factor in particular. Part I analyzes states' efforts to apply the HCD factor to nontriggermen without meaningful direction from the U.S. Supreme Court. Part IV argues that, even after Tison, the HCD factor should not be applied to a nontriggerman accomplice unless the state establishes a connection between the accomplice's state of mind and the triggerman's manner of killing. Without this connection, the factor cannot serve its purpose of identifying the most horrible crimes and criminals and unconstitutionally denies defendants an individualized determination of blameworthiness. Finally, Part V proposes a model HCD statute.