Force Science News #298:

Supreme Court rules on trooper who fatally shot at moving vehicle

In this edition:


I. Supreme Court rules on trooper who fatally shot at moving vehicle

II. Does voice-based technology really improve driving concentration?


I. Supreme Court rules on trooper who fatally shot at moving vehicle


The U.S. Supreme Court recently decided a case involving fatal shots fired at a moving vehicle that provides an important reminder to officers about thoroughly articulating use of force and offers help to police lawyers in arguing qualified immunity cases, according to two prominent law enforcement attorneys who are also Force Science instructors.


• For officers facing a use-of-force review, Attys. Scott Wood and Laura Scarry agree, the case underscores the critical importance of providing a detailed, step-by-step account of how the force encounter evolved and why critical decisions were made.


• For lawyers defending officers accused of excessive force, the Court's written opinion, in Wood's words, contains "good language that will help them argue" for the dismissal of lawsuits without trial where the circumstances justify it.


Wood and Scarry are faculty members for the Force Science program on body cameras and Scarry also instructs for the certification course on Force Science Analysis.


The case, decided 8-1 early in November in favor of a Texas trooper who killed a threatening suspect during a brief high-speed pursuit, is Mullenix v. Luna. Click here to get a free copy of the full decision.


SHOWDOWN AT CEMETERY RD. The shooting occurred nearly six years ago during a nighttime, 18-minute chase on I-27 in north Texas as a suspect tried to flee arrest on an outstanding warrant at speeds between 85 and 110 mph.


As responders from multiple agencies joined in, the driver twice called a police dispatcher, "claiming to have a gun and threatening to shoot at officers if they did not abandon their pursuit," according to the court's recap of the encounter. The dispatcher relayed this warning "to all concerned officers," along with the impression that the suspect "might be intoxicated."


Tire spikes were set up at three locations, the first beneath an overpass at the aptly named Cemetery Rd. A trooper armed with a rifle took a position on the overpass, 20 feet above the interstate, and anticipating the suspect's approach contemplated shooting at the car "in order to disable it." He had "not received training in this tactic and had not attempted it before," the court notes.


His supervisor advised him to "stand by" and "see if the spikes work first," but the trooper claimed later he didn't hear this advisory.


Moments later, the suspect's car roared into view. As it closed on the overpass at 85 mph, the trooper squeezed off six shots, intending to hit the engine block. Instead, four bullets slammed into the suspect's upper body. The car "engaged the spike strip, hit the median, and rolled two and a half times," the driver dead from the trooper's rounds. "There was no evidence that any of [his] shots hit the car's radiator, hood, or engine block," the court says.


REASONABLE? Inevitably, the suspect's survivors filed a federal 1983 lawsuit, claiming the trooper had violated the driver's constitutional rights "by using excessive force."


The district court denied a motion by the trooper's attorney for summary judgment on the ground of qualified immunity, ruling that there were "genuine issues of fact as to whether [the trooper] acted recklessly, or acted as a reasonable, trained peace officer would have acted in the same or similar circumstances."


An appellate majority subsequently agreed that the lawsuit should go forward, concluding that the trooper's use of deadly force was "objectively unreasonable" and violated the suspect's Fourth Amendment rights. The court pointed out that there were "no innocent bystanders" in jeopardy when he fired, the suspect's "driving was relatively controlled," the trooper had not given the "spike strips a chance to work," and his ultimate decision "was not a split-second judgment."


The law, the appellate decision stated, is "clearly established" that an officer may not "use deadly force against a fleeing felon who does not pose a sufficient threat of harm to the officer or others."


Now the Supreme Court has reversed that finding, ruling that the trooper is entitled to qualified immunity shielding him from civil liability in lieu of a trial. Here's the Court's reasoning:


DOCTRINE DEFINED. Put simply, the Court says, the doctrine of qualified immunity is intended to protect "all but the plainly incompetent or those who knowingly violate the law."


A "clearly established" law or constitutional right must be one that is so sharply defined that "every reasonable official would [understand] that what he is doing violates that right...beyond debate," the Court explains (emphasis added).


"The general principle that deadly force requires a sufficient threat hardly settles this matter... We have repeatedly told [lower] courts [in weighing qualified immunity] not to define clearly established law at a high level of generality." The key question is "whether the violative nature of particular conduct is clearly established." In other words, what matters is "the specific context of the case, not a broad general proposition."


The specifics of this case, ranging from the suspect's repeated threats to kill officers to the dangerous uncertainties of relying on unpredictable spike strips, made it impossible to say that the trooper acted "plainly incompetent" or "knowingly violate[d] the law," the Court says.


"The Court has never found the use of deadly force in connection with a dangerous car chase to violate the Fourth Amendment, let alone to be a basis for denying qualified immunity....


"Qualified immunity protects actions in the 'hazy border between excessive and acceptable force.'... [W]hatever can be said of the wisdom of [the trooper's] choice, this Court's [legal] precedents do not place the conclusion that he acted unreasonably in these circumstances 'beyond debate.'...


"The fact is that when [the trooper] fired, he reasonably understood [the suspect] to be a fugitive fleeing arrest at speeds over 100 miles per hour, who was armed and possibly intoxicated, who had threatened to kill any officer he saw if the police did not abandon their pursuit, and who was racing towards [an officer's] position."


ATTORNEYS' VIEWS. "This case by no means gives officers blanket approval to shoot at moving vehicles," police attorney Laura Scarry told Force Science News. "It's not a 'bright line' case in terms of defining specifically what officers can and can't do in that circumstance.


"But I like it because it stresses the absolute importance of good articulation. As an officer, you have to be able to explain in detail why you took the action you did in a force situation, and the trooper in this instance was able to explain the potential dangers that prompted him to shoot.


"The Supreme Court is strongly reminding lower courts that force has to be assessed on the basis of particulars in any given situation, not on the basis of some one-size-fits-all generality."


Scott Wood observes: "Judges are not shielded from what's going on in the world and what they see on TV. From time to time, they may drift away from the specific guidelines given them by the Supreme Court.


"In this case, the Court reminded them that objective reasonableness regarding the use of force must be judged on the totality of circumstances. If it was reasonable for the officer to believe what he did and act as he did in a given incident, then the officer should be granted qualified immunity to liability.


"Qualified immunity at the district court level does not seem as easy to obtain these days as it was four or five years ago. This case can be helpful to lawyers defending officers against allegations of excessive force because its language clearly reinforces the precedents favoring immunity that have been established by the Supreme Court and that attorneys need to incorporate in their arguments."


In reading the full Court decision, police attorneys also may find instructive, as well as entertaining, the rebuttal the majority of justices gave to liberal associate justice Sonia Sotomayor, the sole dissenter, who attacked what she called the trooper's "rogue conduct and " 'shoot first, think later' approach to policing."


An interesting counterbalance to her dissent is a separate opinion, concurring with the majority, by associate justice Antonin Scalia, in which he argues that the trooper didn't really use deadly force in this instance because he was aiming at the vehicle, not the driver!


Laura Scarry can be reached at:; Scott Wood at:


II. Does voice-based technology really improve driving concentration?


The premise underlying certain common traffic laws is that multi-tasking behind the wheel--tuning a radio or placing phone calls while driving, for example--is safe so long as it is "hands-free."


A new study of drivers interacting with automotive voice-controlled information systems shoots that premise in the heart.


Not only is there a significant cognitive load--and thus, heightened distraction--associated even with speech-based functions, researchers found, but vocal interactions impose a detrimental burden on the brain that lingers on even after a given task has ended.


This effect persists long enough that even a vehicle traveling at only 25 mph can cover the length of more than three football fields before a motorist can focus once again solely on driving.


The study, conducted for the AAA Foundation for Traffic Safety, was headed by Dr. David Strayer, a professor of cognition and neural science at the University of Utah. It can be accessed in full, free of charge by clicking here.


DRIVING/SPEAKING TESTS. Strayer and his team recruited 257 drivers, evenly balanced between males and females, ranging in age from 21 to 70, with five to 55 years of driving experience and no at-fault accidents in the last five years. After passing a defensive driving course, they were assigned among 10 different models of 2015 vehicles, each equipped with its manufacturer's auditory/vocal in-vehicle information system (IVIS) that enabled voice-controlled phone calling, number dialing, and radio tuning.


After being familiarized with his or her IVIS system, each driver maneuvered a 2.7-mile street loop through a light-traffic suburban residential area, obeying stop signs and stoplights and the 25 mph speed limit.


As they drove, the subjects completed a series of six intermittent vocal tasks, including tuning their radio to various AM and FM stations and making phone calls by voice-dialing or using their contacts lists. They were allowed a minute and a half to complete each task, and their responses were recorded by monitoring equipment that measured reaction time, accuracy, and gaze tracking.


Afterward, the subjects rated how mentally and physically demanding the tasks were, how much time pressure they felt, and how "insecure, discouraged, irritated, stressed, and annoyed" they were by the various activities.


After five days at home when they were to practice with their IVIS system, the subjects returned for another round on the test course.


COGNITIVE COSTS. In analyzing their findings, the study team reached these conclusions:


• Using a voice-based system to complete common tasks produced "a significant increase" in a motorist's cognitive workload, compared to simply concentrating on driving. Overall, the workload ratings were "surprisingly high," by the researchers' calculations, averaging 3.34 on a five-point scale and ranging from 2.37 to 4.57.


The average and upper ranges were "significantly more demanding than typical cell phone conversations, which have cognitive workload levels around 2.3," Strayer writes.


This "should serve as a caution that these voice-based interactions can be very mentally demanding and ought not to be used indiscriminately while operating a motor vehicle."


Not surprisingly, the systems that were "more intuitive, less complex," and faster in completing tasks had lower workload scores "than more rigid, error-prone, time-consuming ones." Unfortunately, the researchers point out, "[m]any of the systems that are currently available tend to be complex and error prone, with inconsistent behavior...."


• Older drivers experienced a "significantly greater" cognitive impact than those who were younger and more likely to be tech savvy. Even when just driving, the reaction time of older drivers tended to be about 18% slower than that of younger subjects. "In essence, the age-related differences...doubled when participants interacted with the IVIS." This gap is amplified even further "as the complexity of the task increases," Strayer writes.


This is important, he points out, because older drivers (55-64 years old) are the "most frequent purchasers of new vehicles" and thus are likely to encounter voice-based systems that "induce high levels of cognitive workload."


• Practice doesn't seem to matter much. "Even after five days of practice, there were still large [cognitive] costs associated with IVIS interactions," compared with non-distracted driving, Strayer writes. "It appears that the impairments from using the IVIS cannot be practiced away.... IVIS interactions that were easy on the first day were also easy after five days of practice, and those IVIS interactions that were difficult on the first day were [still] relatively difficult to perform after five days of practice."


He cites what he calls "the Power Law of Learning," which posits that "the biggest improvements occur early in training.... This implies that any additional practice [beyond five days] will have diminishing returns...."


• Voice-based tasks affect gaze behavior. Instead of encouraging drivers to keep their eyes on the road, "we found that many participants routinely glanced at the [visual] displays" on their dashboards during interactions, even though the tasks had no visual requirement, Strayer notes. The frequency of important glances "to the forward roadway and side- and rear-view mirrors" correspondingly decreased.


"[I]t is increasingly evident that natural visual scanning behavior is fundamentally coupled to cognitive processing demands," he states. "Quite simply, it is incorrect to assume that talking to your car is an 'eyes-free' activity."


• Perhaps the biggest stunner of the study is "evidence of persistent [cognitive] interference following the IVIS interactions." The impact of a momentary cognitive diversion lingered for up to 27 seconds after an IVIS interaction had been completed before returning to the baseline performance of sole-focused driving.


"To put this in context," Strayer explains, "at 25 mph a vehicle would have traveled 988 feet before the residual [cognitive] cost had completely dissipated"--the length of more than three football fields.


"Just because a driver terminates a call," Strayer warns, "does not mean that they are no longer impaired. This "lingering act of disengaging," he says, has "implications for self-regulatory strategies, such as choosing to dial or send a text message at a stoplight, because the costs of these interactions are likely to persist when the light turns green," as the driver reestablishes "situation awareness of the driving environment that was lost during the IVIS interaction."




© 2017 Force Science Institute Ltd.