Concept
Causation Requirements
Misdemeanor manslaughter
Causation Requirements
The unlawful-act route to involuntary manslaughter excuses the prosecution from proving that the defendant was criminally negligent about the risk of death, and that excuse leaves causation carrying much of the weight of the doctrine. At common law the killing was involuntary manslaughter when a death was proximately caused during the commission of a misdemeanor or other unlawful act short of a felony.1 Proximate cause is the legal connection between conduct and a result, a link strong enough that the law will hold the actor answerable for what followed, as distinct from the bare physical fact that one event came before another. Insisting on that connection keeps the doctrine from collapsing into status liability. A person who commits a misdemeanor and happens to be nearby when someone dies has not necessarily done anything to bring the death about, and without a real causal requirement the rule would punish the status of being a misdemeanant at the wrong moment.
How tight the connection must be is one of the two principal points on which jurisdictions diverge in this area, and a Florida appellate court deciding a malum in se misdemeanor case in Todd v. State treated it as the critical issue.2 Some courts have required no causal relationship at all, while at the other extreme courts require a direct causal relationship and also that the death be a natural and probable consequence of the offense.3 The loose end of that range has produced striking results. In Reed v. State a Texas court held a defendant liable for manslaughter after the defendant, who was committing adultery (then a misdemeanor in Texas), killed the wife's husband while defending himself against the husband's murderous attack, reasoning that the attack was a foreseeable reaction to the misconduct.4 In Commonwealth v. Mink the defendant was attempting suicide when her fiancé intervened and was accidentally killed, and because suicide was an unlawful act malum in se the court found her guilty of manslaughter.5
The category of the predicate offense tends to predict where a court sits on that range. When the misdemeanor is malum in se, courts often relax the proximate-cause inquiry, because the wrongfulness of the act already supplies the blame the rule needs, which is also why no separate foreseeability showing is demanded there. When the misdemeanor is malum prohibitum, most courts require a close causal link, because a regulatory violation says nothing by itself about culpable risk-taking, and the causal requirement is then the only remaining tie between the defendant and the death. The three subsections below take up the basic link, the treatment of frail victims, and the point at which an offense ends for causation purposes.
Causal Link Required
The baseline requirement is that the unlawful act be a proximate cause of the death, and the thing that must be connected to the death is the conduct that makes the act unlawful.6 It is therefore insufficient that a defendant who committed a misdemeanor has somehow brought about a death; the chain of causation has to run through the misdemeanor conduct itself. Take a defendant who argues heatedly with another person and then strikes that person, who dies of a cerebral hemorrhage. If the medical evidence cannot show whether the blow or the excitement of the earlier argument set off the hemorrhage, the prosecution has not tied the death to the unlawful conduct, because the argument was lawful and cannot supply the predicate.7 The battery is the misdemeanor, and only what the battery did counts toward liability.
Licensing offenses show the principle at its sharpest, because the violation often changes nothing about how events unfold.8 A driver whose license lapsed last month is driving with ordinary care when a pedestrian darts into the road and is struck. The lapsed license is a real violation, yet a driver holding a current license would have been in the same place at the same speed, so the paperwork lapse made no difference to the death. The unlawful act did not cause the harm, and the expired-license driver discussed in the preceding section escapes for exactly this reason. Change only the violation and the result flips: if the driver had run a red light and struck a pedestrian crossing with the signal, the unlawful conduct is what carried the car into the pedestrian's path, and the causal link is present.
Because the doctrine borders on strict liability, it is sometimes said that only cause in fact is needed, meaning that the death would not have happened but for the misdemeanor. That view is wrong, and students lose this issue when they treat cause in fact alone as enough. The ordinary rules of legal cause apply, so the link breaks when an intervening coincidence that is not reasonably foreseeable, or an abnormal response, stands between the conduct and the death.9 The same logic is applied in felony murder: a kidnapper who is driving carefully when an unforeseeable accident kills the captive is not guilty of murder merely because kidnapping is a felony.10 A rule satisfied by but-for causation would reach every death that happened to occur during a misdemeanor, and presence at the scene would become the offense.
The strictest courts add a further layer. In Votre v. State an adult gave whiskey to a minor in violation of a statute, the minor suffered a heart attack caused by the alcohol and died, and the Indiana court held that the defendant was not guilty of manslaughter because the death must follow both as a part of the perpetration of the unlawful act and as its natural and probable consequence.11 A requirement of that kind asks whether the death is the sort of result the offense makes likely, which is nearly the question asked in criminal-negligence manslaughter, and its effect is to convert the unlawful-act theory into something close to that older theory.12
Step two is where regulatory predicates usually fail, and step three is where even a lenient jurisdiction stops, since courts that relax proximate cause for malum in se offenses still refuse to charge a defendant with a freak coincidence. The fourth step matters because the same facts can pass in a jurisdiction that accepts ordinary foreseeability and fail in one that insists on a natural and probable consequence.
Frail Victims
When the unlawful act is an assault or battery, the causal link survives the victim's unusual frailty, because the defendant takes the victim as found. The causation rules in misdemeanor manslaughter are the ordinary ones, so the familiar homicide principle that a defendant answers for a death even though a stronger person would have survived carries over when the predicate is a battery.16 The reason lies in what battery is. The offense consists of force applied to another person's body, so the risk that a body will fail under that force is the very risk the offense creates. If a defendant could escape because the victim happened to have a weak heart or a thin skull, the law's protection would shrink exactly where bodies are most vulnerable, and the defendant would profit from a condition the defendant had no right to assume was absent.
A patron who shoves a stranger in a line at a bar commits a misdemeanor battery. If the stranger has an undetected heart condition and collapses and dies, a person in robust health would have stumbled and recovered, but the shove is still a proximate cause of this death, and the defendant's ignorance of the condition does not interrupt the chain. The principle has limits that the earlier material already supplies. It concerns the victim's physical condition and does not relieve the prosecution of tying the death to the battery, which is why the cerebral hemorrhage that could not be traced to the blow produced no conviction. And it belongs to assaultive offenses. In Votre the offense was supplying liquor to a minor, no force was applied to the minor's body, and under the natural-and-probable-consequence standard the heart attack was not a death the offense made likely, so the defendant was not guilty.17 Replace the whiskey with a blow and the analysis changes character, since bodily harm is then what the offense inflicts and the victim's vulnerability only magnifies a harm of the kind the offense carries.
Flight After the Offense
The rule asks for a death proximately caused during the commission of the misdemeanor, which raises the question of when the commission ends.19 Read literally, an offense is complete the moment its elements are satisfied, so a battery is finished when the blow lands, and a death a few seconds later would fall outside the doctrine. In most jurisdictions the answer is more practical: for causation purposes the offense continues through the offender's flight from the scene, particularly when the flight begins immediately and pursuit follows. The reason is that flight is the foreseeable continuation of the crime. Offenders ordinarily run, and a chase brings the risks of speed, panic, and collision, so a death during that stretch is explained by the offense as much as one that occurs while the blow is being struck.
The ordinary causation rules still do the limiting work. A defendant who commits a misdemeanor battery outside a bar and bolts for his car, with the victim's friends running after him, may speed away and strike and kill a pedestrian. The battery was technically complete when the blow landed, but the death arises out of the immediate flight, and a court applying the majority view treats it as occurring during the commission of the offense. The driving may also support other theories, such as criminal-negligence manslaughter, which an exam answer should note. Move the death in time and the answer shifts. If the same defendant had escaped, driven home, and stayed there overnight, and a fatal collision occurred the next day on an ordinary commute, nothing connects the death to the misdemeanor, because the flight had ended and the offense's consequences ended with it. Students lose points here by treating technical completion of the offense as the end of the causal window, when the question is whether the death grew out of the continuing flight.
The tension between the lenient and strict approaches reappears at this boundary. A jurisdiction that insists on a natural and probable consequence asks more of a death during flight than one that accepts ordinary foreseeability, because the chase must then be shown to make death a likely result of the offense.20 When a question does not state the jurisdiction's position, apply the majority treatment of flight and note the stricter alternative.
Causal Link Required
The unlawful-act route to involuntary manslaughter lets the prosecution skip proof that the defendant was negligent about the risk of death, because it is enough to show that the unlawful act caused the death.22 That shortcut leaves causation as the only tie still connecting the defendant to the victim, so the causal requirement has to carry real weight. The baseline rule is that the unlawful act must be a proximate cause of the death, and the thing that must be connected to the death is the conduct that makes the act a crime, not everything the defendant happened to be doing when the death occurred.23 A defendant who commits a misdemeanor and is simply nearby when someone dies has not necessarily brought anything about. Without a genuine link, the doctrine would become liability for the status of being a misdemeanant at the wrong moment.
The standard failing case is a licensing violation. In Commonwealth v. Williams the defendant was convicted of manslaughter by vehicle, and the unlawful act supporting the conviction was driving after failing to renew a driver's license. The Pennsylvania court reversed, holding that the expired license had no causal connection to the accident, which resulted from the carelessness of another driver.24 The driver had been operating the car without negligence, and the collision would have unfolded identically had the license been current. Liability under the rule is supposed to rest on what the unlawful conduct contributed to the death, and the lapse contributed nothing.
The reason a licensing offense fails so reliably lies in what a license is. A license records that the state has checked, or will check, a person's qualification to carry on an activity, and an expired one records that the paperwork lapsed. The activity itself, whether driving or hunting, is lawful, and only the missing authorization is unlawful. Courts sometimes describe this by splitting the defendant's conduct into a lawful part and an unlawful excess: a driver going 35 in a 25 zone is lawfully driving at the first 25, and a hunter without a license is lawfully hunting in every respect except the absent license. One line of authority holds that the defendant is not liable unless the death was caused by that unlawful excess.25 Where the defendant would have been entitled to the license on request, the missing paper changes nothing about how the activity was carried out, so the unlawful excess cannot have produced a harm that a fully licensed person would have produced in the same way. Holding the defendant answerable anyway would convict someone for a death that another person's carelessness produced, on the strength of a regulatory lapse unrelated to that death.
A qualified hunter who has not yet bought this season's license, who handles the rifle with care, and who still kills a fellow hunter in an accident illustrates the point. A rigid application of the misdemeanor-manslaughter rule would convict, because the hunter was committing an unlawful act when the death occurred, but the missing license bears little or no causal relation to the death, so the conviction should fail even at common law.26 A driver whose taillights are dead stands differently. That defect concerns how the car presents itself to other drivers, so it can connect to a collision in a way a lapsed license cannot, and the rule has been applied to convict such a driver even when the driver was not negligent about the defect.27 The facts of the violation, and not its label as a misdemeanor, decide whether the link exists.
This is the same line the prior section drew for malum prohibitum offenses, and the licensing cases show how the limits operate. A regulatory violation says nothing by itself about culpable risk-taking, so courts that restrict the doctrine for such offenses require either that the death was a foreseeable result of the violation or that it was caused by the unlawful excess. Commonwealth v. Williams, the expired-license case, is cited for the foreseeability view, a case involving practicing cosmetology without a license is cited for the unlawful-excess view, and State v. Hupf states the common point directly by requiring proximate cause in every unlawful-act case, whether or not the offense is malum in se.28 For malum in se misdemeanors the usual rule dispenses with both the foreseeability showing and the unlawful-excess showing.29 Even so, stricter courts still enforce a causal limit against malum in se predicates. In Todd v. State, defendants stole $110 from a church collection plate and fled, and a congregant who pursued them by car suffered a cardiac event, hit a tree, and died. The Florida court reversed the manslaughter conviction because that death was not a foreseeable risk of the theft.30
Licensing cases outside the expired-license pattern fail for similar reasons. In an Ohio case, a defendant committed the misdemeanor of allowing an unlicensed person to drive. The driver started the car only to run the air conditioning, and a four-year-old passenger then fell onto the gear shift and the accelerator. The court held that the licensing violation was not the proximate cause of the death, since unforeseeable events intervened between the violation and the fatal movement of the car.31 Compare an assault. If a defendant lightly punches a victim who falls and fatally strikes his head on the sidewalk, the battery is the unlawful conduct, there is no lawful remainder to separate from it, and the battery is what put the victim on the ground, so the link is present. The same battery fails to support a conviction when the proof breaks down. A defendant who argues heatedly with another person and then strikes that person, who dies of a cerebral hemorrhage, cannot be convicted if the medical evidence leaves open whether the blow or the excitement of the earlier lawful argument set off the hemorrhage.32 Change only the medical finding, so that the blow is shown to have triggered the hemorrhage, and the link is established.
Because the doctrine comes close to strict liability, it is sometimes said that only cause in fact is needed, meaning that the death would not have occurred but for the misdemeanor. That view is wrong, and students lose this issue when they treat but-for causation alone as sufficient. The expired license fails even the but-for inquiry, since the driver would have been driving anyway. A careful kidnapper whose captive dies in an unforeseeable accident passes the but-for inquiry, because the captive would not have been in the car without the kidnapping, yet legal cause is missing, because the accident was a coincidence that was not reasonably foreseeable. The ordinary causation rules apply in these cases, so legal cause is absent when an unforeseeable coincidence or an abnormal response intervenes.33
Step two is where regulatory predicates usually fail, and step three is where even a lenient jurisdiction stops. The fourth step matters because identical facts may support a conviction where ordinary foreseeability suffices and fail where the court insists on a natural and probable consequence.
Frail Victims
The causal link examined just above raises a sharper question when the victim turns out to be unusually fragile. A defendant commits an assault or battery meaning to hurt someone and nothing more, yet the victim dies because of a weak heart, a thin skull, or a blood deficiency that the defendant had no way of knowing about. Where the unlawful act is an assault or battery, the near-universal answer is that the defendant takes the victim as found. The death is then proximately caused by the act, meaning the law will charge the defendant with it, and the victim's frailty does not interrupt that chain.38 A moderate blow with a fist that kills a person with an undiagnosed heart condition therefore supports involuntary manslaughter, even though a healthy person would have absorbed the same blow without lasting harm.
The principle reaches threatened force as well as applied force. If a defendant closes in on another person intending to strike but not to kill, and the target, who has an undetected heart weakness, suffers a fatal seizure from fright, the defendant is guilty of manslaughter although the two never touched.39 Courts reasoning the same way have sustained manslaughter convictions where a simple assault produced an unanticipated death, as in State v. Frazier, a Missouri decision from 1936.40 In each of these situations the defendant's own conduct was the intentional infliction or threat of bodily harm, and that feature carries the result.
The reason is an allocation of risk. A person who chooses to inflict bodily harm on another has already decided to cross the line the law draws around the human body, and the only question left open is how bad the harm will be, which depends on the physiology of the person struck. Between a defendant who chose to injure and a victim who did nothing, the rule places the risk of an unexpectedly severe outcome on the one who chose. This parallels the tort rule that a wrongdoer takes the victim as found, and courts in these jurisdictions reason that one who intentionally injures another must assume the risk of even an unforeseeable death.41 The rule also removes a perverse incentive from the other direction. If liability shrank as the victim's vulnerability grew, an attacker's exposure would be smallest against the people who are easiest to kill, and the defendant would profit from a condition that the defendant had no right to assume was absent. In every case of this kind the fatal result is a magnified version of the very harm the offense inflicts, which is why the magnification is charged to the defendant.
Tom punches Jerry once during an argument, and Jerry, who has hemophilia unknown to Tom, bleeds internally and dies. The battery is a misdemeanor that is wrong in itself, the unusual frailty is not so extraordinary as to count as a superseding cause, and Tom is guilty of misdemeanor manslaughter. Tom's ignorance of the condition and the unexpectedness of the death are both beside the point, because the punch is the offense conduct and it set the fatal process in motion.
The principle has limits, and they come from the ordinary rules of causation, which apply in misdemeanor-manslaughter cases just as they do elsewhere. The frail-victim principle speaks to how severely a body responds to the harm the offense itself inflicts. It gives the prosecution no help when the proof fails to tie the death to the offense conduct at all, so a defendant who argues heatedly with another person and then strikes that person cannot be convicted if the medical evidence leaves open whether the blow or the excitement of the argument set off the fatal hemorrhage.42 Legal cause is likewise absent when an unforeseeable coincidence or an abnormal response intervenes between the unlawful conduct and the death.43 A victim's fragile heart is a condition the offense acts upon, while a coincidence or an abnormal response is something independent of the offense that arrives afterward, and only the second kind of event breaks the chain.
Hold the unexpectedness of the death constant and change the offense, and most jurisdictions reverse the result. A driver slightly exceeds the speed limit, and a pedestrian unexpectedly dashes into the road and is killed. Speeding is a malum prohibitum offense, wrong only because a regulation says so, and where the doctrine is limited for such offenses the death must have been a foreseeable result of the violation.44 A sudden dash by a pedestrian is not a result that a few miles per hour over the limit made likely, so the speeding did not proximately cause the death and the doctrine does not apply. The same reasoning controlled Commonwealth v. Williams, where a driver who non-negligently killed another person while driving on an expired license was not guilty of manslaughter, because the failure to renew the license did not proximately cause the death.45 Speeding can still support liability when the excess speed actually contributed to the collision, and separate theories such as criminal-negligence manslaughter may remain open to the prosecution, but neither changes the answer under the unlawful-act route on these facts.
The two outcomes look inconsistent until one asks what each offense says about the defendant's choices. A battery is an intentional invasion of another person's body, so an unexpectedly severe injury lies within the risk the defendant chose to run, and proximate cause is relaxed to the point that the unforeseeability of the death does not help. A regulatory violation involves no choice to put anyone's body at risk, and the unlawful feature, such as a modest excess of speed, says little by itself about culpable danger to others. Most states therefore demand a closer showing that the violation, and not some independent event, brought about the death. The offense is the variable that moves the answer, since the death surprises the defendant in both situations. Students go wrong by carrying the frail-victim principle over to every misdemeanor when it belongs to assaultive offenses. The assault-and-battery branch of the doctrine has itself been criticized as harsh and as lacking a rational theory of punishment, and the closing material on the modern status of the rule returns to the jurisdictions that have abandoned it.46
Flight After the Offense
The causal link discussed above raises a timing question whenever the unlawful act is finished before anyone dies. The rule reaches a death that occurs in the commission of the misdemeanor, and a literal reading of that phrase would end liability the instant the last element of the offense is satisfied. In People v. Mulcahy, an Illinois decision, the requirement was stated as one of timing: the death must occur within the res gestae of the unlawful act, meaning within the events that make up the offense as one continuing episode.48 The phrase sets a boundary, and the question here is where that boundary falls once the thing the defendant set out to do has been done.
A driver who commits the misdemeanor of speeding, slows to a lawful speed, and a few minutes later, while driving properly, strikes and kills a pedestrian shows one side of the boundary. It may be true that, had it not been for the speeding, the driver would never have been at that spot, so the death can be traced back to the violation by a but-for chain. Yet the accident took place some distance away and some time later, and that gap may take the death out of the in-the-commission requirement.49 The speeding had ended, and what followed was lawful driving. Cause in fact therefore cannot stretch the offense to cover every later event the offense happened to set up.
Flight after a crime stands differently, because the escape is a continuation of the offense and not a separate later episode. In most jurisdictions, flight that follows the crime, especially flight with the victim in immediate pursuit, is treated as part of the crime, so a death during the chase still occurs within the res gestae of the unlawful act.50 The reason follows from what the rule is trying to capture. Liability attaches to the continuous course of conduct that created the danger, and pursuit and escape are the natural continuation of that conduct. If the offense were treated as over at the instant of completion, a defendant could escape responsibility for deaths that flowed directly from the crime, and the most dangerous stretch of the episode, the run from the scene, would be the one stretch the law refused to count.
A thief who steals from a gas-station operator and bolts across a busy highway, with the operator right behind, illustrates the point. The operator is struck by a passing car and dies. The larceny was technically complete once the thief carried the property away, yet flight with immediate pursuit is part of the crime, so the death falls within the rule. The chase is an unbroken sequence that begins with the taking, and the thief's choice to run into traffic is what put the pursuer on the road. Students lose this issue when they treat completion of the offense as the end of liability, because the relevant question is whether the death came during the continuing episode of crime and escape.
The flight principle answers only the timing question, and the causation standards from the preceding discussion still apply. In Todd v. State, defendants stole $110 from a church collection plate and fled, and a congregant who pursued them by car suffered a cardiac event, struck a tree, and died. The reported ground for reversing the manslaughter conviction was that the death was not a foreseeable risk of the theft, not that the death came too late.51 A court that insists on foreseeability even for a malum in se predicate will therefore ask it about a chase as well. The highway facts are the easier case for the prosecution, because a pursuer struck by traffic has met a hazard that running into a road itself creates, while a pursuer's sudden cardiac failure behind the wheel is a more remote product of the theft.
Change the facts so the episode has ended, and the answer reverses. The same thief takes the cash, reaches a friend's house across town, and is not followed. Hours later the operator, driving to report the theft, dies when a drunk driver crosses the center line. The theft is long over, no pursuit connects the two events, and nothing about the offense produced the collision. The better analogy for this endpoint comes from felony murder, which counts a death that occurs during the underlying crime or in immediate flight from it.52 Courts in that setting usually stop counting once the felon has reached a place of temporary safety. That limit is borrowed from a neighboring doctrine to predict where a court will draw the line, and it is not a rule announced for misdemeanors. The misdemeanor decisions mark the endpoint with the res gestae requirement and the causation inquiry, as in the speeding example above.53