By the end of any given movie, almost all Marvel Cinematic Universe villains are either in prison or deceased, with only a select few managing to eke out a kinder fate. Though we may see them for a moment or two behind bars, what is rarely discussed is the actual process of trying and convicting a supervillain. And that's unfortunate, because it would probably make for some of the most complicated legal drama ever put on film.
Given the mortality rate in MCU supervillains' line of work, a prison sentence might seem like a favorable outcome - but that could change once the jail-time is actually tallied up. The entire franchise might have leapt five years into the future in Avengers: Endgame, but it's going to take a lot longer than that for some of these characters to see the light of day again.
Adrian Toomes has one of the least violent rap sheets of any MCU villain, but he's still going away for a long time. First and foremost, each and every theft of technology committed by Toomes while in his Vulture get-up would qualify as grand larceny at least - making him eligible for 25 years per count in the state of New York. Presumably, the selling of said alien tech - like the ill-fated incident on the Staten Island Ferry - would be treated similarly to transactions involving nuclear materials, and net Toomes another 20 years.
Then there's his slaying of Jackson Brice, the original Shocker. When Brice threatened to leave Toomes's illicit enterprise and expose his secrets, Toomes meant to detain Brice with an anti-gravity device, but he accidentally vaporized him with a Chitauri ray-gun instead. A good lawyer would argue this down to manslaughter in the first degree, but that's still another 25 years.
Finally, the Vulture made his big play by hijacking Tony Stark's superjet full of goodies, which earns him at least 20 more years for aircraft piracy. Given the damage caused by the resultant collision and the dangerous nature of what he was trying to swipe, Toomes can count on another 20 years on top of that - and that's being generous.
Helmut Zemo makes for an interesting case. His greatest act of villainy, splitting up the Avengers, isn't really against the law - there's no law against showing someone a video of his best friend's best friend assassinating his parents. But Zemo made up for it by committing some very serious offenses on the way to his big moment.
Dressed as the Winter Soldier, Zemo bombed a United Nations event, resulting in dozens of casualties - an act of international terrorism that would garner either life in prison or capital punishment, depending on the court trying him.
To get at the incarcerated Bucky Barnes, Zemo took out a UN psychiatrist in Berlin - in the first degree, no less, meaning life in a German prison - and then impersonated him, earning three additional years.
To cap it all off, Zemo traveled to Siberia and executed five additional Winter Soldiers while they slept in cryogenic stasis - meaning five more counts of murder in the first degree. Since these five were committed in Russia, he wouldn't be slain himself, but he would pick up five extra life sentences.
Alexander Pierce was the Secretary of the World Security Council. He was also an international terrorist, intent on launching an maneuver through Project Insight that would have resulted in 20 million targeted casualties.
Though the attempt was ultimately unsuccessful, several S.H.I.E.L.D. agents were still slain along the way, meaning Pierce should be charged to the full extent of the country's terrorism laws. He's looking at life in prison at a bare minimum, and possibly capital punishment. Add on additional life sentences for any other past HYDRA schemes he's been involved with.
The fundamental question raised in Pierce's trial - had he lived to attend it - would have been whether his actions constituted treason. Technically speaking, HYDRA was neither a foreign power nor an active enemy of the United States at the time Pierce was working for the organization, so he would probably escape a treason conviction by a narrow margin.
Of all the MCU villains, Ava Starr is probably the least evil, and at the very least, she has one of the most relatable motivations: She just wanted to get her hands on the technology that would keep her alive.
As Ghost, Starr definitely swiped some privately owned tech - including an entire miniaturized laboratory - which basically amounts to corporate espionage. At most, that's going to net her 15 years in prison. She may have also done some light kidnapping, but that charge would only be raised if Hank Pym made an issue out of it.
Sure, Ghost's actions may have threatened the life of Janet van Dyne, but good luck trying to convict someone for attempted murder via botched quantum realm extraction. There's every chance Ava walks away clean from all this.
Most of what Justin Hammers does in Iron Man 2 is annoying and unethical, but only a select portion of it is deserving of jail-time. First and foremost, there's his breaking Ivan Vanko out of prison - that's good for five years right there.
Then, Hammer harbored Vanko in his own place of business while Vanko designed drones for him. Harboring a fugitive nets Hammer an additional five years. There was probably some corporate espionage involved in Hammer's Iron Man-esque technology, but there's also nothing onscreen to explicitly prove it.
Vanko's strike on the Stark Expo was against Hammer's wishes, but it was only made possible because Hammer sprung him from prison and gave him access to weapons of war. In addition to reckless endangerment, that should mean that, for every victim of the Hammer drones, Hammer is found guilty of involuntary manslaughter - worth two years per count. There's no way there weren't at least a dozen casualties in all that chaos.
The real danger for Hammer, however, came during that aforementioned breakout. Part of the scheme involved the execution of another prisoner as a stand-in corpse for Vanko. If Hammer himself gave the order for that to occur, that's murder for hire - and that could put him away for life, or worse.
The transgression Thanos committed when he snapped half of all living beings out of existence is the sort that could only really be tried by the International Criminal Court, or something similar. It was, at best, a crime against humanity - not to mention, in more stark terms, outright genocide.
International courts have handed out life sentences for participation in the Rwandan genocide, but there's also the precedent of the Nuremberg Trials, which saw several Nazis hanged for their part in the Holocaust. One has to think Thanos would fall into the latter category - especially if his trial were to occur before everyone was brought back to life. The ICC currently does not use capital punishment, but it might make an exception for the Mad Titan.
Executing Thanos, however, is a difficult proposition. A lethal injection isn't going to work, nor is an electric chair or firing squad. He almost certainly can't be successfully hanged, and if an attempt is made and he survives it, what then? Some precedents suggests he would just be condemned to life in prison at that point, so maybe it's better to start with that.
