I wrote this article for Graphic Justice, but it looks like they wanted something more 'academic'. Anyway, they didn't get back to me before the deadline, so I'm publishing it here. You can tell me what I got wrong, though I'm fairly certain I got the premise correct.
The battles between the forces of “good” and “evil” in comic books are certainly colorful, flashy, and exciting. What they are never, unfortunately, is clean. Civilians get hit by debris and missed shots, vehicles get wrecked, dogs in nearby apartments never stop barking, and combatants can get killed. We won’t cover the legality of whether or not a person can be charged with murder for killing a superhero when the heroes get resurrected on an almost monthly basis. Rather, we will consider the international legal consequences (if any) as well as specific local United States consequences if the following event occurs:
If a vigilante superhero, while responding to a crisis, executes a captured or incapacitated villain during a battle.
ULT: Whether or not a hero faces legal trouble for the execution depends on the circumstances of the execution.
Vietnam execution at Saigon during Tet Offensive and military law in general
There is one incident that is burned within the minds of Western people. Dating back to the Vietnam War, the Tet Offensive in 1968. Long story short (Washington Post, 2018), a war correspondent named Eddie Adams took a photo of Gen. Nguyen Ngoc Loan executing captured Viet Cong commando Bay Lop. The photo was one of many that led the American public to consider the brutality involved in fighting the VietCong during Tet and became fodder for anti-war protests.
The reasoning behind the execution is that Bay Lop led an assassination squad that killed the families of South Vietnamese National Police officers. He was caught while at the site of a mass grave (Wikipedia, 2018).
With these facts in hand, what can we say about the legality of the execution?
Justice for Bay Lop seems like a moot point since Gen. Loan was not tried by the South Vietnamese military court or by the tribunal. There are probably extenuating circumstances related to the reason but we’ll focus on what I consider to be the primary reasons (New York Times, 1972)
The Viet Cong were not a signatory nation or party.
The Viet Cong did not wear signifying attire.
The unit led by Bay Lop had engaged in war crimes and thus lost whatever Geneva Conventions protections they had. According to the 3rd Geneva Conventions (regarding the treatment of prisoners) Article 4, forces not openly carrying arms, wearing signifying attire, or not following the laws and customs of war are not legal combatants and not guaranteed POW status, thus making the unit civilian criminals.
The battle for Saigon was ongoing (martial law) and Loan had the authority to make the execution.
The United States and its allies were knee-deep in their own war crimes issues and wanted things ‘swept under the rug’ (Los Angeles Times, 2006)
Military law is quite strict on the issue of summary execution and no-quarter combat. Many national military guidebooks disallow executions without trial except in the gravest of circumstances, mostly related to continued threat from the target (IHL page). This is the gray area where battles involving superhumans enter the picture. This author has decided to take you through two examples of superhuman battles that meet the criteria for exceptions.
Executions in Darfur 3 Saga and Superman vs the Elite
In my debut novel Super Humanity, the city of Cleveland is invaded by an interdimensional kingdom with plans to conquer the Earth. At the end of chapter 19, the Darfur 3 superhuman team had captured an enemy commander. At the start of their interrogation, they receive a radio call from Control (the world hero agency regulated by the UN), alerting them to the capture of an elite hero team. Deciding that rescue takes priority and with no guaranteed location that could store the dangerous prisoner, they execute the prisoner with an energy pistol. The execution is recorded by human survivors and streamed worldwide.
The Darfur 3 win the battle, but face a tribunal hearing with war crimes over the execution. Long story short, they win their trial, thanks to their “lawyer” (a first year law student) successfully proving these three key points.
The enemy was not a person, but an interdimensional non-human combatant, and thus not subject to the Third Geneva Conventions.
The hostile interdimensional power was engaging in genocide, thus allowing for legal reprisal attacks under Rule 145 (ICRC), assuming if the invading kingdom would be considered a ‘legal’ state by the UN or the ICC. Rule 148 of the ICRC regard reprisals does not apply here in on the basis that the invading kingdom’s ruler had informally (did not file a document) declared war on the Earth upon setting foot on US soil.
Guellocks, the attacking interdimensional kingdom, was not a signatory nation to the Convention, nor did it request protections.
While the Darfur 3 superhuman team were found innocent of this particular crime, the many, many, many other war crime accusations made the United Nations more willing to pursue charges on this matter only.
We move on in examples to the comic book movie Superman Vs the Elite. The Elite are essentially expys of The Authority team from Image Comics, pre-Kingdom Come. The relevance of this trivia is that the Elite are heroes that kill bad guys. We are treated to a visceral example of this during a battle in Metropolis.
The Atomic Skull broke out of prison (somehow) not too long after Superman put him in there during the opening sequence of the movie. It should be noted that Atomic Skull committed mass murder to attract Superman’s attention. Keep that point in mind as we continue with the story.
Later in the movie, Atomic Skull attacked Metropolis. During the battle, Superman is weakened, but still able to coordinate an attack with the Elite that drains the Atomic Skull of his powers. Defenseless, the villain is then executed by the Elite leader, after asking for permission from a kid whose father was killed by said villain.
After the execution, the Elite leader and Superman have an argument about the executions they have committed. Superman wants the Elite to stand trial, but the Elite are not interested and instead set the stage for the climatic showdown.
For academic interest, let us speculate what would occur if the Elite went on trial for the execution of Atomic Skull. This trial, despite Atomic Skull and the heroes turning the city into a ‘battlefield’ would not be considered a war crimes trial because the victim was not a member of an armed force recognized by the UN. Therefore, the trial would be considered under local laws.
I believe that the Elite would likely have been found innocent, if even in the unlikely event a grand jury had been convened. There are a few circumstances with the Atomic Skull’s actions that make this the likely outcome. Let’s assume Metropolis courts has the same relevant laws as our USA does. I believe they would on the following reasons.
The 1986 ruling of Tennessee vs Garner states that officers have the right to shoot if "the officer has probable cause to believe that the suspect poses a significant threat of death or serious physical injury to the officer or others." (Tennessee v Garner). What was the escaped criminal doing at the time? Killing people and fighting superheroes. To be fair, this ruling applies to police officers, which the Elite were clearly not. However, they were the responding force on the ground at the time and the police were clearly shooting to kill in the scene. It should be further noted that the ruling mainly applies to escaped felons, which Atomic Skull was at the time.
If you assume that Atomic Skull was a human criminal, you can surmise that the incidents involving him are more akin to mass shootings than military battles. As such, you can presume that armed civilians (in this case, The Elite) would not face prosecution for engaging the threat with lethal force. The argument this author makes is based on the Mark Kram case in Dade County in 1982 (fun fact: the DA there was Janet Reno, Pres. Clinton’s Attorney General). In that case, the assailant Carl Brown opened fire on a metal shop then rode away on a bicycle. Mark Kram chased him down in his car, shot him in the back, and rammed him into a light pole (NYT, 1983). “But the threat’s power was neutralized,” the prosecution might say. For how long? Could the Elite have taken the criminal to a holding facility in time? As you recall, Atomic Skull broke out of the holding facility. The Elite (or their lawyers) could make the argument that the threat was too dangerous to be contained at the prison. They could cite recent US actions involving drone strikes against US citizens in Yemen (Anwar al-Awlaki, for example), however they are not a military authority, which might complicate the argument.
A guide for super vigilantes
Let’s say you’re a superhero (or well-prepared vigilante) and you need to know the legality of summary executions of your opponents in a combat situation. Follow these guidelines to determine whether or not you might face legal sanction.
Local sentiment plays a role.
Whether or not you may be prosecuted by the local or international authorities may also be dependant upon the public sentiment regarding the battle and your role in it.
For example, the local DA may still press 2nd degree murder charges if the locals that elected them are angry that you hack-slashed your way through an orphanage of brainwashed children to kill the threat. While you can’t control the efforts of the local DA (without breaking the law), you can document your actions (and the villain’s) so should you be arrested and forced to stand trial for the whole orphan-hacking thing, at least you will be able to mount a defense against that particular charge.
All other charges associated with vigilante superhero activity: those are beyond the purview of this paper and no legal advice is given for those.