Unit 17: Heat of Passion Manslaughter


  • Dressler 501-511 (through 31.07)

  • Girouard (CP)

  • Casassa (CP)

Key Terms: 

  • heat of passion

  • adequate provocation

  • reasonable person


At common law, an intentional homicide committed under a “sudden heat of passion” resulting from “adequate provocation” will be graded down from murder to intentional manslaughter. “Sudden” means the actor must not have had time to cool off. Additionally, there must be a causal link between the provocation, the passion, and the homicide. Passion can include any number of emotions, including anger, fear, jealousy, and desperation.

Adequate provocation is the amount of provocation that would cause a reasonable person to fall into a heat of passion. This threshold was generally provided at common law through fixed categories, including: aggravated assault or battery, observation of spousal adultery, commission of a serious crime against a family member, mutual combat, or illegal arrest. Learning about adultery second-hand, unfaithfulness by a non-spousal partner, and “mere words” were not enough to satisfy adequate provocation. Today, adequate provocation is usually a jury question. Specific jury instructions vary by jurisdiction, but the basic requirement is that the jury must find the provocative conduct sufficient to render a reasonable person temporarily incapable of rational judgment. At common law and in most jurisdictions today, “mere words” do not qualify as adequate provocation. The categorical exclusion of mere words is slowly breaking down (and does not exist in the MPC, see §31.10(C)(3)(b)).

The “reasonable person” standard is difficult to define, and, given the unreasonableness of manslaughter, more accurately might be called the “ordinary person” or the “ordinarily reasonable person.” Some common traits are an even temper, sobriety at the time of the incident, and average mental capacity. However, there is a trend towards subjectivizing this standard by considering the defendant’s personal characteristics and background. This trend can influence how one views the effect of the provocation on the defendant, and the level of self-control that can reasonably be expected. But the precise degree to which the standard should be subjectivized remains unclear. Courts generally find subjectivization more acceptable when dealing with the gravity of provocation than with the subjective personality of the defendant. For example, a court would be more willing to subjectivize provocation that was offensive to the defendant but wouldn’t be offensive to most people, but less willing to subjectivize the defendant’s particularly short temper. These are not hard and fast rules, however.

Traditionally, the “sudden” requirement was strictly applied – the killing had to take place immediately following the provoking act, with no cooling off period. Today, the amount of time between the provocation and the criminal act is more often seen as a jury question.

Historically, the heat of passion doctrine mitigated a murder verdict, because murder had a mandatory death penalty. Courts also justified the doctrine based upon conceptions of honor. Do these explanations hold up today?

Questions for Review:

Q1. Jeff and Larry get into an argument. Larry calls Jeff a lazy bastard, and claims to have slept with Jeff’s wife. Jeff, who has suspected his wife of infidelity in the past, becomes so enraged that he pulls out a gun and shoots Larry in the chest. Larry dies as a result of his injuries. Is Jeff entitled to a heat of passion defense?

Q2. Alex slept with Lauren’s husband. Lauren did not witness the event, but Alex takes every opportunity to remind Lauren that it occurred, mocking her ceaselessly. One day, after some particularly cruel taunting, Lauren decides she can’t take it anymore. She immediately pulls out her gun (which she always carries with her) and shoots, killing Alex. Is Lauren entitled to a heat of passion defense?

Q3. Same facts as above, except instead of immediately killing Alex, Lauren goes home, puts her gun (which she normally leaves at home) in her bag, and thinks to herself, “Next time Alex taunts me, I am going to shoot and kill her.” The next day, Alex once again taunts Lauren, and Lauren immediately pulls out her gun, shoots, and kills Alex. May Lauren use a heat of passion defense?

Q4. Why do some jurisdictions recognize a heat of passion defense? Does it matter whether we view it as a justification or an excuse? Should it exist at all?