I’d assume that the “not my jurisdiction” zone just means that no agency is doing patrols there, and that, if a body is found there’s a round of: “it doesn’t sound like it’s on my budget,” before someone finally steps up and handles things with everyone’s concurrence. It might matter where the victim lives.
This. One of the world’s most wanted people of the 1990s and 2000s, Radovan Karadzic, evaded arrest for twelve years, hiding in Belgrade and Vienna as a miracle healer. And that was with a globally enforceable warrant and a $5m bounty against him.
The police departments in the SF Bay Area have a particularly poor record of catching serial killers. And when they do, it takes like 50 years.
There’s a little more to it than that. Trying to try someone who committed a felony on that land would (technically, at least) violate the Vicinage clause of the Sixth Amendment. From the article I linked to:
The issue has to do with the fact that nobody lives within that 50 square-mile section of Yellowstone located in Idaho, according to the 2020 census. The fact nobody lives there could become a problem if a criminal defendant on trial for, say, a murder or kidnapping that took place in that precise area, evoked their Sixth Amendment right to be tried in front of a jury from the state and district where the crime occured.
“So under the legal theory, if there is no one that lives in that state and district in this 50 square-mile swath of Yellowstone Park, there would be no constitutionally legitimate jury to be seated so that person could be tried,” Nash told members of the House Judiciary, Rules and Administration Committee on Thursday afternoon.
A legal paper from 2005:
Let me nitpick here, because I have a fascination for this loophole. The issue is not that there is no state or local jurisdiction in the “Zone of Death”; the issue is that, because of the way state and US District Court boundaries are drawn, a jury to try crimes in this area would have to be composed of people from that area, and it is uninhabited. So in terms of jurisdiction there is nothing magical about it; it’s the practical impossibility of setting up a valid jury that gives it its peculiarity.
Ever since Inspector Callahan retired things just haven’t been the same there.
Truth. Not to mention that since Lt Mike Stone and Inspector Steve Keller departed, the Streets of San Francisco are dangerous indeed.
Fewer careening Camaros and Ford sedans roaring through the most picturesque of intersections then getting airborne. So probably net net safer for tourists on foot. 
Legal types - what’s the problem with arresting the “suspect” and holding him in jail without bail until trial? The fact that the trial can’t happen without the co-operation of the defense is totally not the prosecution’s problem. Let the person rot in an over-crowded, underfunded pit for the rest of their days.
MOre than one legal expert has weighed in saying this is a fun bit of legal trivia, but if a crime there needed prosecuting, the general rubric of the law to do the sensible thing, not a stupid thing, would govern and there’d be no actual obstacle to a trial and a conviction.
Of course there’d be an appeal, but any sane appeals court would say that doing justice is more important than mocking justice over a pettifoggery.
There’s a greater chance that he’ll be the first one they suspect, because they all know him as that creepy weirdo kid who’s probably a serial killer.
Yeah, that’s also a possibility. I think I said that in the rest of that post.
Perhaps. But perhaps the appeal court would rather take the view that letting one guilty guy go is the lesser evil compared to ignoring the clear and unambiguous constitutional text of the Sixth Amendment. We don’t know as long as it hasn’t happened.
FWIW, it’s not an entirely novel way of thinking in legal reasoning that there may be considerations that are more important than capturing every single guilty guy. It’s this logic that lies behind the presumption of innocence and the rules on admissibility of evidence.
Ahhh…b.b.b.but what if I 'm a sovereign citizen? You can’t arrest me! I HAVE RIGHTS!!!
And since the only true jurisdiction is based on the maritime charter with yellow fringes, you have no authority…this part of Idaho is MINE!
I find being adjacent to Canada very appealing, so I’d choose Washington.
The question is how easy would it be to sneak over the Canadian border.
Maybe in the 80s and 90s but security is tight in the Canadian border. A Lithuanian immigrant was arrested from trying to cross the US border illegally through Canada via driving. There was a Canadian business man running for politics named Kevin Johnston who tried to illegally enter the US through the Canadian border to evade prosecution but got arrested.
Anyplace you can cross with a car is watched, but I very much doubt the border is monitored in the remote Montana-Idaho-Washington mountains. A reasonable strong hike should have no problems sneaking across in the summer. Would be harder but still possible in the winter.
You may be better concealed as a carnival flatulist. Nobody would want to get near you to investigate.