Maybe it will be a jealous astronaut who decides to eliminate a rival in an orbital love triangle. Or maybe being cooped up in a spacecraft on an interplanetary flight will cause one crew member to flip out and finally lose it at a colleague's annoying nose blowing. Or maybe it will be a killing made to look like an accident, in order for a co-conspirator to collect an insurance policy back on Earth.
But sooner or later, it seems likely to happen, given humans' propensity for committing homicidal violence against one another all over the world. Somebody is going to commit a murder in space or on another planet or moon, and, when it happens, authorities will have to figure out how to catch the perpetrator and bring him or her to justice.
But it's not going to be easy. Investigating a murder in space would be vastly more complicated and difficult than probing a crime on Earth. And law enforcement agencies and courts may have to deal with tricky, complex jurisdictional issues that end up requiring negotiations among spacefaring companies. And until the laws are rewritten, judges will have to take statutes and legal standards that were developed to deal with murder allegations on Earth and figure out how to apply them to accusations of lethal violence in space.
Legal Jurisdiction Extends Into Space
You might be surprised to learn that nations already have legal jurisdiction that stretches outside the confines of this planet. That's covered by Article VIII of the 1967 Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies. It specifies that whenever one of the nations that's a party to the treaty launches an object — i.e., a spacecraft, satellite or space station — into space, or builds one on a celestial body, that nation retains jurisdiction and control over it.
Thus, according to legal experts, if a U.S. astronaut is accused of killing another American while traveling in a NASA spacecraft or a commercial space vehicle launched from the U.S., the FBI and federal prosecutors would be within their authority to arrest the alleged killer and bring him or her back to Earth for a trial in federal court.
Things might get a little more complicated if the murder occurs on the International Space Station, and the alleged killer and the victim are citizens of different countries.
"Article 22 of the 1998 Intergovernmental Agreement concluded between the parties deviates from the aforementioned international treaty clauses and by contrast concedes jurisdiction to the state of nationality of the offender," writes Frans G. von der Dunk, the Othmer Professor of Space Law at the University of Nebraska-Lincoln's College of Law, in an email. However that comes "with the caveat that if the life or safety of persons with other nationalities and/or the safety of the space station is at stake, consultation should take place with these other countries concerned on which country should actually initiate prosecution, which may result in the country of nationality of the victim doing that."
However, "that agreement only covers the International Space Station," Michelle Hanlon, associate director of the Air and Space Law Program at the University of Mississippi School of Law, explains in an email.
What About Citizen-astronaut Crime?
Things could get even more complicated jurisdictionally, Hanlon says, if there's a killing on a future private-sector orbital hotel, the sort of place where she thinks it is more likely to occur. "If you have 400 civilians in space, you know crime inevitably is going to happen. We send the most disciplined and fit people, the best of humanity, to the ISS. With a hotel, you're not going to be able to impose the same standards. You need to make money. You're going to get a lot greater variety of people, and you know there is going to be crime, possibly from stealing a watch all the way to murder."
Who actually qualifies as the hotel's "launching state" with jurisdiction under the 1967 treaty could be murky, too, Hanlon continues. It could be nation A, which is home to the company that operates the hotel, or it could be the nation B, where the installation's components were manufactured — or nation C, where the launch pad for the rocket that transported the parts into space was located. Or nation D, home to the company that rented the launch pad. "Arguably, any of these states could have jurisdiction," she says.
As a result, crimes in space — particularly incidents involving nationals from different countries — most likely would lead to diplomatic negotiations to see who gets to take charge, Hanlon says.
Where Does National Sovereignty End?
And what if an astronaut on a spacewalk decides to, say, cut another astronaut's tether? The victim could spin off and possibly be drawn back into the Earth's atmosphere, where he or she would be burned to death, a fate described in this 2013 Popsci.com article. Who would have jurisdiction then, since the act would have occurred outside of an object controlled by a nation?
"Although there is no sovereignty outside a spacecraft, there are analogies to the law on ships in international waters and also to issues that might occur in Antarctica; both places with no national sovereignty," Henry R. Hertzfeld, a research professor and director of the Space Policy Institute at George Washington University's Elliott School of International Affairs, explains via email.
"So, although this is not a settled issue, my reading is that being in space and technically outside of any nation's sovereignty or jurisdiction is not sufficient to avoid being charged with a crime," Hertzfeld says. "As above, any person in space has a national citizenship, is the responsibility of the launching state or the person's state of citizenship for their activities in space and would be tried for a violation of the law in the appropriate state. Within a nation such as the U.S., different laws might apply depending on the nature of the crime and the ownership of the vehicle or place where the crime took place."
We're Gonna Need Space Cops
But let's assume that the U.S. takes jurisdiction over a space murder. Investigating the crime and building a case is going to be tricky, considering that the crime scene and potential witnesses are outside the Earth. "You may have to add a whole new profession — space cop," Hanlon says. "There's going to be a tremendous cost to send somebody into space just to investigate a murder." In fact, it may drain resources that would go to other things that we want astronauts to be doing, such as performing research and exploring the cosmos.
And gathering evidence in space or on another planet or moon might be especially difficult. As this 2018 Atlantic article explains, DNA — increasingly, a key means of identifying perpetrators — would age differently on Mars than on Earth, because of the increased exposure to solar radiation due to the red planet's thinner atmosphere. Additionally, lower gravity would lead to such things as different splatter patterns from stab wounds. On the plus side, the ubiquitous Martian dust clinging to the exteriors of space suits and other surfaces might provide a valuable new sort of evidence.
"It creates incredible complexities," Hanlon says. But even so, she figures that investigators and prosecutors will find a way to deal with it. "Our law developed before fingerprints and DNA. When you prosecute a criminal case, you do what you can with what you're given."
Space murder may also require the courts to grapple with Fourth Amendment issues, since astronauts are continually being monitored in myriad ways, including on video. "There's a value to having cameras in every room of a spacecraft," Hanlon says. "But do you have an expectation of privacy?" Hanlon expects that many of these questions will be resolved by wise judges and lawyers.
But she'd also like to see spacefaring countries come together and work out a new international agreement on how to work together on handling future crimes in space. "What we don't want is an international space regime that has very different concepts from jurisdiction to jurisdiction," she says. "Hopefully, we can explore space together as a species and have common understandings."