What’s the Matter With “Bomb Robots”?

Posted in: Constitutional Law

Following a non-violent Dallas protest march against racially biased police brutality last week, Micah Johnson—who acted on his own and directly contrary to the methods advocated by the leaders of the Black Lives Matter movement who organized the march—shot twelve police officers and two civilians, killing five of the officers. Other police officers gave chase and cornered Johnson in a garage. After negotiating for two hours in the hope of inducing him to surrender, gunfire was exchanged between Johnson and the police. But that gunfire did not kill him. Instead, Johnson was killed when the police sent a “bomb robot” into close proximity of Johnson and then remotely exploded it.

Although police have used robots in other circumstances, this was apparently the first time that domestic law enforcement has used a robot to deliberately kill a criminal suspect. With opinion divided over the legality and wisdom of the bomb robot, it may be useful to separate a number of distinct issues that the bomb robot raises.

This column considers three questions: Does the bomb robot represent an important technological change in policing? Does the bomb robot improperly import a military tool into domestic policing? And does the bomb robot violate the Constitution?


The term “bomb robot” no doubt conjures frightening images of killer robots from science fiction. People who have seen Robocop, the Terminator films, or Battlestar Galactica may form mental images of malevolent machines acting on their own robotic sense of justice.

Some day in the not-too-distant future these fears could become reality. Already, we have semi-autonomous machines capable of killing people. They’re sold by Tesla, with Google and other companies working on their own versions.

But the bomb robot deployed by the Dallas police was more like a heavy-duty remote-control car with a mechanical arm than a Cylon. In many respects, a bullet fired from a gun is a kind of bomb robot. It is unleashed at distance and has a lethal impact at its target. The chief difference is that the bullets do their damage without the further remote control signal from the operator.

Yet that difference would seem to make the bomb robot less scary than a gun-launched bullet. Once the human operator has discharged his gun, the bullet does its work. By contrast, the police bomb robot requires two human acts to wreak its havoc: First, the officers send the bomb robot on its mission; and second, they remotely detonate the bomb.

To be sure, one might think that the ability to kill by remote control makes bomb robots especially dangerous. Some people argue that military drone aircraft lower the emotional cost of killing and thus make killing in wartime more likely. The operator of the drone does not directly see, and thus does not feel, the immediate impact of the death he unleashes from above.

I have my doubts about whether distance in fact disinhibits killing. Drone operators in silos thousands of miles from their target see camera images that may be as clear as or clearer than what is seen by pilots operating manned bombers. Meanwhile, people are capable of horrific killing even face to face. Hundreds of thousands of the victims of the Rwandan genocide in the 1990s were killed with machetes and clubs.

Thus, while I share the uneasy sense that this first use of a bomb robot in domestic law enforcement may lead us down a path that we come to regret, it is difficult to see this initial step as carrying us very far down that path.

Weapons of War Come to the Home Front

Another concern about the bomb robot is that it reflects the militarization of policing. After the unrest in Ferguson, Missouri, during 2014, many people pointed to the police use of tanks and other weapons and tactics of warfare as a serious problem facing the country.

There are at least three concerns with respect to militarization. First, these weapons can cause too much damage. The law of war forbids military combatants from ordering or carrying out attacks that cause “disproportionate” civilian casualties. That rule reflects the grim truth that war is hell. By contrast, in our domestic life, just about any civilian casualties are disproportionate. Yes, there are rare circumstances—such as a hostage situation—in which police must make the tragic choice to attack a criminal in circumstances that will likely lead to some innocent people dying, only to avert the deaths of even more. But in general, the calculation of acceptable “collateral damage” is much more conservative in civilian life than in warfare.

A second concern about militarization is that a militarized police can come to see the population as “the enemy.” Riding through city streets in their armored vehicles, they will perceive threats where they should be seeing the people they are sworn to protect and serve.

Third, there is a worry that when police departments acquire sophisticated military weaponry, they will use it. Even if there exist rare circumstances in which deploying tanks in an urban setting makes good sense, police—being human—will find it tempting to use their advanced weaponry when a more modest approach would be more appropriate.

These are all legitimate concerns, but it is not clear that the Dallas bomb robot implicates any of them. The bomb exploded in an isolated area, killing only its target without causing collateral injury. The Dallas police under the leadership of Chief David Brown have made good relations with the community a priority, notwithstanding the power of their arsenal. And the use of the bomb robot rather than some lower-tech method of killing Johnson appears to have been motivated by concerns for officer safety; the police were not simply itching to use their high-tech toy.

Excessive Force?

While police militarization may not have played a substantial role in the Dallas police officers’ decision to kill Johnson with a bomb robot rather than in some other way, questions nonetheless remain about whether the decision to kill him at all was justified under the standards applicable to domestic law enforcement. In war, it is permissible to kill enemy soldiers even if it might be possible to capture them (so long as they have not surrendered). But under the Constitution, the police may not simply kill a criminal suspect.

The Fifth and Sixth Amendments guarantee rights (such as the right against self-incrimination, to a jury, and to counsel) that would be circumvented if the police could simply kill suspects—even pretty clearly guilty suspects like Johnson. Extra-judicial execution is implicitly but clearly forbidden by such provisions.

The provision of the Bill of Rights most directly on point is the Fourth Amendment. It prohibits “unreasonable” “seizures,” and the Supreme Court has quite sensibly held that the use of deadly force is a “seizure” of the person—indeed, the ultimate seizure. Was the killing of Johnson “unreasonable”?

That depends on facts that are not yet fully public. In describing the standoff above, I relied on news accounts—almost certainly sourced from the police themselves—that reported that after about two hours of negotiations, gunfire erupted. Such reports leave key questions open. Who fired first? Was anyone in imminent danger when the police decided to kill Johnson? Might the police have been able to capture Johnson without further bloodshed had they attempted to continue negotiating? Were they in the line of fire while negotiating? Did they reasonably believe that there might be bombs planted (as Johnson reportedly claimed) or other shooters at large?

The leading Supreme Court case is Tennessee v. Garner, which establishes that police may use deadly force to apprehend a fleeing felon but only if they have probable cause to believe that he poses a danger to them or the public and they cannot safely capture him alive. Yet Garner is not entirely on point, because Johnson was cornered rather than fleeing. Was an escape route open to Johnson? More broadly, just how patient must police be when confronting an armed criminal who has already demonstrated his willingness, indeed his eagerness, to shoot police officers and civilians?

Further factual investigation may help answer these questions. However, the key facts concern the justification for the use of deadly force, not the method by which the Dallas police killed Johnson. If it would have been reasonable to shoot him, then, under the circumstances, it was reasonable to kill him with a bomb robot.

Put simply, the answer to the question whether it was reasonable—and thus constitutional—for the police to deploy a bomb robot to kill Johnson might be no, but if so, that’s not because they killed him with a bomb robot rather than with a more conventional weapon.

  • G.N.M.

    There was still great danger from the decedent. He still had his weapons and had already wounded numerous people and killed five police officers. In no way was the use of a robot excessive force to stop this miscreant from further killing. Your mention of Tennessee v. Garner is irrelevant to the facts of the case. The police had a duty to stop him without considering whether he had an avenue of escape.

  • Linda J LeBlanc

    I believe since Johnson used a military assault weapon the only option the police had was to also use that type of weapon. They had to kill him or be killed. His hate and armor piercing bullets had already killed some of them so approaching him was out of the question.

  • J.E. Tarrant

    Did you mean for your first paragraph to say following the violent protest of the racist hate group black live matter, which has consistently advocated the murder of Police Officers and white people in general, Micah Johnson acted in concerted with the group, oh and our President, and shot and killed 5 police officers, wounded 12 others, as well as 2 civilians? It’s interesting because that first part of your article is so woefully inaccurate as to almost seem like intentional sarcasm.

    All that aside, it does place some perspective on the totality of the circumstances. There’s a group of “protesters” that have a propensity for violence and starting riots nearby. Emergency Services needs to access the injured. Cornered does not mean not able to project fire unto others, nor does it mean that what it takes to keep a suspect “cornered,” does pose a threat to others. It is unfortunate that we have people teaching the law who have obviously never had to practice it, and people passing judgment on gunfights who have obviously never been in one.

    • Derek Aktion

      Wow … I read this site for thoughtful commentary on the law.
      Not for white supremacist conspiracy theories recycled from breitbart and infowars that are too insane to refute.
      Professor Dorf thanks for an interesting essay.

      • J.E. Tarrant

        “White supremacist,” is an interesting term to throw around. It denotes an irrational world view (particularly because of genetic mixing) and, by assuming that the person you’ve affixed the label to is irrational, it allows you to not consider the merits of their arguments. Skin color has little to do with ethnic-political violence. It isn’t responsible for what’s happening in the Central African Republic now, or what happened in Rwanda, or Cambodia, etc. BLM is a hate group. Racism is responsible for the plight of many blacks, but not the way it’s being sold. It’s the racism of lower expectations and the destructive force of the welfare state, which has done the same thing to poor Scandinavians, poor British, etc. The real racism is believing that black people cannot behave themselves and we need to swoop in and save them.

  • BunnyHooHoo

    He was intentionally targeting police officers. His use of body armor proves premeditation. He had already killed and wounded multiple officers. He had two hours to surrender but chose not to. He was in a defensible position and armed to the hilt. What kind of madman would require officers to go into that situation to see if the assassin would maybe have a change of heart? He could have surrendered in 10 minutes. That means that by the 11 minute mark a reasonable person could conclude that the assassin was not going to surrender peaceably. There doesn’t need to be bombs planted or other shooters at large. There was a shooter at large.
    The most probable outcome of dragging this out was the further loss of innocent life. How can a use of force policy that sends officers to certain death be ethical or in the interests of society? This is madness.