# Law enforcement in FTL civilization

The civilization has discovered an semi-unspecified type of FTL drive and spread among stars, but only a small portion of the stars in the galaxy is explored, settled and administered. Beyond the edge of administered space, there are some settled systems, beyond them are some more which are only explored or being explored, but the vast majority of the galaxy remains unexplored and this is changing very slowly.

The question:

How can the law enforcement catch the criminals who could simply run away from the administered space?

Let me clarify the available technology.

## FTL ships

Faster than light travel is achieved via unspecified means and it expends fuel proportional to the distance traveled. While using the FTL drive, the ship keeps existing in the "normal space" and continuously changes its position (i.e. not wormhole). The ship is not restricted to preexisting pathways (i.e. not hyperdrive), except for the need to avoid obstacles, which are rare, localized and mostly near the stars, because the space is realistically empty (i.e. no "anomalies" and dangerous nebulae, just a boring universe as we know it).

There exists a preferred reference frame, relative to which the FTL travel happens and there is no violation of causality.

Travel time between two systems is reasonable. For smaller ships, it is comparable to the travel time between two larger cities by a car in the beginning of the 21st century. Range without refueling is similarly comparable.

### Availability

The FTL drive is surprisingly easy to manufacture. In fact, so easy to manufacture that many ordinary people have a small cozy FTL-capable starship, equivalent to contemporary cars, but slightly bigger, allowing people to live in them.

### Other standard tech onboard

Even the smaller car-like starships obviously have life support. They also have rudimentary matter synthesizer/recycler, allowing indefinite replication of simpler foods and smaller 3D-printed structures, as long as the needed matter and power is available. Ships have airlocks and EV suits in case you want to take a (space)walk. Finally, they are able to suck surrounding fluids, which can be used as fuel and/or building material for matter synthesizer/recycler. To refuel, collecting hydrogen will do, and this can be trivially done in the most of the systems.

## Other

No alien civilizations are discovered in the galaxy. The life seems to be incredibly rare, only few planets with unicellular life are discovered and maybe one or two with multcellular life, but none with anything even remotely resembling the central nervous system.

• Interpol, expecially Interpol notice. Letters rogatory. It's not as if international judicial coöperation has to be invented anew. – AlexP Aug 21 '18 at 11:24
• Watch Firefly - basically answers your question! – Daniel Aug 21 '18 at 11:25
• @AlexP there is no administration in the unexplored space, so there is no one there to whom you can send something like an Interpol notice. – Danijel Aug 21 '18 at 11:29
• @Danijel: So what are the wrong doers doing there? Eventually they will have to come back from the wilderness into civilization, and then the long arm of the law will seize them. – AlexP Aug 21 '18 at 11:35
• How can the law enforcement catch the criminals who could simply run away from the administrated space? Is this a requirement? Why bother? Is banishment/exile not enough of a punishment? Sounds like you're approaching this from a very modern criminal justice standpoint. Historically speaking, the way we approach criminal justice now is an aberration that makes almost no sense and provides few benefits at a very high cost. Worth asking if your world would copy/paste our current, unusual approach to criminal justice. – HopelessN00b Aug 21 '18 at 17:11

# Use real world examples?

Criminals could 'run away' to the Americas or wherever in the 1600s. In that case, how would the Spanish crown capture them? What about outlaws that fled to the territories in the 1870's United States? Or Russians that escaped to Siberia in the 18th century?

First off, this is exactly how pirates came about. If you have people running away from law enforcement, and then forming a community, then they are basically a band of outlaws. If they also have ships, then they are pirates. Since pirates make everything better, and you have an excuse to use pirates, you now have to use pirates; especially since the only thing better than pirates is space pirates. It is science. In this case, pirates or outlaw gangs of the outer systems are dealt with by the navy.

The colonial powers of Europe probably didn't actually spend too much time tracking down escapees. The point of law enforcement is to make sure society runs the way the powers in charge want it to run. Since the people in question are trying to flee society, there isn't much need to keep them in line. If they come back as a rebellious army, then that is a problem, but that is more of an armed forces problem than a law enforcement problem.

In sparsely populated border regions, without much law enforcement, there are two basic methods for keeping order, amply covered in Western movies. Either the locals can elect and arm some people to keep the peace, or itinerant lawmen can rove the stars, bringing order to planets in chaos (I made that up myself). Sounds like an awesome 1980 Saturday morning cartoon.

The last example I gave was of people fleeing into Siberia. The Russians had reached the Pacific by the mid 1600s (much earlier than the equivalent in the US) but the place remained pretty wild until the Trans-Siberian railroad came through around 1900. Lots of people fled into the wilds; these generally fell into two groups. The first is the Old Believers, a breakaway sect of the Orthodox church that was generally banned in Russia proper.

The second group were the Cossacks. Cossack history extends back towards ~1400, and they generally occupied the steppe region from the modern Ukraine all the way to the Amur region of Russia. People seeking to escape from civilization might fall in with the Cossacks. The Cossacks were generally left to their own devices by the Russian government in return for military service. In this way, they co-opted a lawless society to serve teh state. You can read all about Cossack life (which was to settled Europe what cowboys were to settled America in the late 1800s) in literature.

# Conclusion

1. Criminals who run away form bands of pirates and are dealt with by the Navy.
2. Criminals who run away are an outlaw menace, but defended against by border settlements' self-elected lawmen.
3. Criminals who run away blend in with the populace and are pursued by Marshals on an individual basis.
4. Criminals who run away join groups of religious and social outcasts which are tolerated by the government that doesn't want them.
5. Criminals who run away join bands of semi-nomads, which are hired as mercenaries for government service on a periodic basis.

...in SPACE!

All of these sound like awesome movies that I would watch.

• @Rekesoft Mining towns in the Outer Reaches are just like mining towns in the Old West; if the miners can survive there, then so can the bad guys. See Outland for the pervasiveness of criminality in distant mining colonies. – kingledion Aug 21 '18 at 11:37
• "Since pirates make everything better, and you have an excuse to use pirates, you now have to use pirates; especially since the only thing better than pirates is space pirates." +1 for that. But yes very sophisticated answer – CKA Aug 21 '18 at 12:06
• The colonial powers of Europe probably didn't actually spend too much time tracking down escapees. Pretty much. Once upon a time, exile was a common punishment for serious criminality, and we mustn't forget Australia... the continent that a certain real-life empire decided was a good place to ship its outlaws to. Catching criminals with the intent to incarcerate them is a relatively recent phenomenon and one that isn't necessarily bound to continue indefinitely. – HopelessN00b Aug 21 '18 at 15:37
• “The only thing better than pirates is space pirates. It is science” - I concur. Now it is peer reviewed science! – Joe Bloggs Aug 21 '18 at 17:07
• "are dealt with by the Navy" aka Space Force! – called2voyage Aug 22 '18 at 18:46

Due to the vastness of space and the lack of distinct "highways," the average law enforcement agency most likely wouldn't bother to pursue individual criminals beyond the edge of explored territory. They could be anywhere in the galaxy, and unless their ships are equipped with devices capable of tracking FTL ships, it isn't worth the effort.

Since both life and civilization are quite rare, as you mentioned, then the criminals would need to make a choice between isolation and risking their freedom. Those who choose the former would flee society and live on their ships, but wouldn't have any place to go or any way to sustain themselves once the food runs out. In that case, they would most likely attempt a raid on a (non-administrated) settlement for supplies. When that happens, local militia or administrative reserve troops can be deployed to deal with the threat.

On the other hand, if the criminals never return to society, then they don't pose a significant danger anyway. They simply live out their lives in unexplored space.

In the meantime, contract "bounty hunters" and other paramilitary could be hired by law enforcement to trawl previously unexplored areas for the refugees. Law enforcement could also seed surrounding systems with sensors that alert them to the presence of ships, and deploy troops accordingly. Edit: Overall, a single criminal isn't worth expending millions of credits in resources. But if criminals find each other and band together to form a space pirate faction (as suggested by kingledion), then admin might get involved directly if they pose a great enough threat. On the flip side, however, the pirate armada would be easier to find than a single criminal ship.

• According to the OP, the food wouldn’t run out. But otherwise, I agree. If the criminal flees and doesn’t come back, it would be economically better for insurance to compensate the only victim. – WGroleau Aug 22 '18 at 0:22
• You're right, I missed the part about indefinite food synthesis. But what qualifies as a "simple food"? "I'm the most feared space pirate in this sector, and I refuse to eat the same bland, artificial glops for the rest of my life. The space tapioca is wreaking havoc on my digestive system, and I'm slowly dying of malnutrition. I'll definitely risk my freedom raiding a colony for something with flavor, maybe something with protein." – Axiom Sage Aug 22 '18 at 0:42

Why would they? If you are concerned with protecting the people and property of a particular volume of space you don't bother with the criminals that leave that volume of space.

Space is far too big to police in its entirety so you watch your corner hit criminals when they come back into your jurisdiction; any ship cross the borders of policed space, especially coming in from the outside, is automatically subject to immediate search and seizure, you might get your ship back if the cops don't find anything suspect, or not.

So your cops should watch the border worlds, the systems close enough to the border to give enough fuel range to ships leaving the policed systems, and DNA test as many people leaving as possible so they know who's going where-ish. They'll take detailed scans of every ship passing through so they know if it comes back or not. Most especially they take an aggressive zero fault policy towards arresting everyone coming into their control space on a guilty until proven innocent basis; anyone leaving is assumed to be on the run unless they have an exploration permit but no-one really cares if criminals leave, its only if they come back that they're a problem.

When the official borders move, because new colony worlds are opened, the same approach should apply; anyone found on new worlds who is not an officially registered colonist gets arrested for criminal trespass and held while they're checked against every criminal database in existence.

• Just to give a current-world analog: I know someone that has an outstanding warrant in Idaho due to a petty crime they committed there. There isn't a single Idaho policeman that is trawling through the other American states to find him and bring him back to Idaho to face justice. It happens currently. – RustyTheBoyRobot Aug 21 '18 at 16:51
• This. The criminal has chosen to exile himself from the jurisdiction in which he committed his crime(s). Unless and until he returns, he is no further threat to the citizens of that jurisdiction. Don't go out of your way looking for them outside the borders, but any outsiders wanting in must be checked against the fugitive database. I wouldn't call it "arrest" so much as "detention" (as happens at border areas IRL) pending further investigation. As a detainee has not even been charged with a crime, detention facilities should be quite a bit more comfortable than jails. – Monty Harder Aug 21 '18 at 18:30
• @RustyTheBoyRobot Yup and as soon as he either draws some attention to his presence back in Idaho, or gets arrested for something elsewhere, I'm guessing Idaho will be only to happy to say something like, "oh him, yeah slap another xyz on for us would you?" that about how it works? – Ash Aug 21 '18 at 18:32
• As soon as they missed their court date, they had another charge added to the list. If they were to go back to Idaho and get stopped for speeding or something mundane, the cops would find that they had an outstanding warrant and make an arrest. – RustyTheBoyRobot Aug 22 '18 at 16:34

Micronutrients.

/We'll catch them when they come back for more food./@Rekesoft

These folks with FTL Volkswagons and food synthesizers - what would they need to return to civilization to get? Not food. Not clothes. Not fuel if they can collect hydrogen. Probably not religious services although that is an interesting idea.

Humans need micronutrients. They are on the vitamin bottle - cobalt, copper, zinc, etc. A matter synthesizer might be able to rearrange readily available carbon, hydrogen, nitrogen and oxygen and make fabric or food. Synthesizing an atom of manganese out of some other matter type requires more doing. Where do you find iodine in space? Recycling your wastes will reclaim micronutrients for a while but recycling is never 100%.

Of course if you don't want this, assert the matter replicator can make your manganese. But this premise presents another fine analogy to scurvy pirates - goiterous, ice-gnawing outlanders suffering the symptoms of gradual micronutrient deficiency and eventually being forced to make a run back to get more from the government monopoly, which doles them out sparingly.

Where are they going to? In our world we already have FTL (Faster Than Law). Criminals can evade justice by car, plane, ship or train. The thing is, where are they going to? Because wherever they go, there will be law agents waiting for them. The only way to escape is going to a place where there is a different jurisdiction that the one you're fleeing from, and they don't have an extradition treaty.

Having FTL engines so simple you can make a DIY one in your garage causes serious troubles with my suspension of disbelief, but even within the premises of your universe, one thing is having a car-like (or small yacht) FTL spaceship and another thing is having a Make-Your-Own-Habitable-Planet-In-Five-Minutes toolkit in its trunk. Yeah, sure, your criminals can flee to the farthest corner of the galaxy. We'll catch them when they come back for more food.

As you said, life is incredibly rare in the universe. Fleeing to nowhere is just another form of suicide, and criminals routinely use suicide to avoid the action of justice. You can't prevent that.

• I think the onboard matter recycler/synthesizer takes care of their food requirement (all that is needed is matter and power). When they are in need of maintenance or spare parts they cannot makes themselves, that is when they'll come back or stay to die. – GretchenV Aug 21 '18 at 13:53
• @GretchenV (+1) I overlooked the replicator part - too much handwaving for me. But in any case, it's a matter of time. Even if they don't die, they are doomed to roam an infinitely empty void in solitary confinement. Prison is preferable. At least in prison you have the company of other inmates. – Rekesoft Aug 21 '18 at 14:02

Here's some nitty gritty details to complement the prior answers:

I assume that the old maxim of a missile being able to outrun anything that has to carry humans still holds true. Hence, first you outlaw any FTL travel within settled star systems. Anyone that wants to travel within "civilised space" must do so at sublight speeds. Violating this rule means you will be fired on by defence batteries armed with FTL missiles, with no exceptions. The no FTL boundary can be expanded to extend up to light-seconds or minutes away with anything entering the threshold at FTL being immediately engaged. As already mentioned by others criminals will come to you rather than the other way around so this is to discourage FTL hit and run attacks.

Once everyone is travelling at sublight speeds, this then opens up lasers, as shorter ranged weapons and also as guidance, communications and so forth. Monitor all traffic with an intra-system detection network and you're back to business as usual; laser-armed patrol ships carrying grunts to do the boarding-related tasks are the new equivalent of cops in cop cars

• Except your citizens and entrepreneurs would want to use your small, little fuel consumption and apparently acceleration neglecting FTL-drive anywhere, including take off and landing planet side. Traditional means of sublight speeds take lots of fuel (apollo capsule on top of saturn V), space and time if you don't want to be squashed. It takes 2 hours to reach the 1 light-second limit with constant 1g acceleration. I'm pretty sure many will make the argument that this is not economical. – GretchenV Aug 21 '18 at 13:10
• @GretchenV Does the FTL drive have a minimum speed though? Otherwise you can still travel at 0.x the speed of light with no problems – nullpointer Aug 21 '18 at 13:26
• The question does not say whether there is a minimum speed nor whether it works in a gravity well. But if I can use my FTL drive planet side and if I was a criminal on a 'raid', I'd zip in at superluminal speeds, do my thing and zip out at superluminal speeds again in less than one second before the lightcone from the sensor a light-second away has reached the command and control post directing the defense batteries. Not that they have anything to shoot at as I'd be using a sort of random walk to the planet so my position cannot be predicted. – GretchenV Aug 21 '18 at 13:43
• Rather than not allowing any FTL within a settled system, there should be a defined area in which FTL is done under strict traffic control. (After all, we can't have FTL ships becoming kinetic weapons by colliding with each other or planets.) Your navigation systems must be able to accept a flight-plan program from the traffic control system, and if you need to deviate from that plan for any reason you must disengage the FTL drive and advise Traffic Control of your emergency, at which time they can authorize a modified plan. – Monty Harder Aug 21 '18 at 18:35
• @MontyHarder That brings up the problem of identity spoofing which I was trying to avoid, but in practice you're probably right. – nullpointer Aug 24 '18 at 5:40

# Other fiction example: Elite

Elite and Elite:Dangerous have managed this problem for 34 years.

The setting is similar to yours: relativistic drives are ubiquitous. Anything from a small one-person ship to huge capital ships can hop from system to system. The range of a hop varies depending on the ship, but anything from 5 to 50 light years is common. Ships can also cruise relativisticly within a system at anything from 30,000 km/s to several hundred times c, i.e. light speed.

Law enforcement exists in the Elite-verse. In short...

• There is Faster Than Light communication, meaning that information can be immediately propagated throughout a whole star system
• Every civilised system has law enforcement that patrol points of interest, and also roaming patrols that may decide to check up on ships at their discretion
• You cannot hide your Faster-Than-Light entry into a system, nor your relativistic mode of travel when in a system, nor when you engage or disengage your relativistic drive
• Your identity is immediately known as soon as someone "looks" at you
• A superficial criminal status can be obtained by making a more detailed scan, in short just focusing on a ship over a few seconds
• Your entire criminal record is known as soon as someone makes a close-up scan of you
• There is a bounty system: known criminals are allowed to be shot on sight
• Your status as a law abiding citizen or a criminal varies depending on what jurisdiction is in effect in that particular system and who scans you. If you are friendly with that faction, they may even come to your aid if someone attacks you.

So how to deal with "slippery fishes"? That is taken care of by the following limitations in relativistic travel:

• You cannot jump to relativistic mode — neither to jump to another system nor to cruise within a system — if there is a large mass close to you. Planets, ring systems, space stations and other ships count. So you can "mass lock" a fugitive and force them to do combat at non-relativistic speeds. Depending on how good their thrusters are, they might be able to outrun you in a straight race, and then make the jump.

• You can be yanked out of relativistic cruising, i.e. "interdicted". But this is a tenuous affair for anyone trying to interdict, and success depends on the size of the interdicted ship, the sophistication (i.e. price) of the interdiction equipment, and the skill of the pilots.

# So what if you run away?

Question: is that really a problem?

Law enforcement may exist for a number of reasons. But dragging you before a court is in and of itself not the goal of law enforcement. That is simply a tool that we use here on Earth today to achieve other goals. And those goals may be...

• Retribution. This is plain old revenge: you did something bad, so now we inflict something bad on you.
• Rehabilitation. This is to make you stop doing bad things and go back to being a productive member of society.
• Reparation. You did something bad to someone else, so now we will make you repair that damage you did to them, forcing you to pay the cost for the loss and pain & suffering you inflicted.
• Prevention. This is to make you not want to do bad things.
• Protection. This is to forcibly stop or disable you from doing bad things to someone else.

Retribution serves little purpose, and it is not unreasonable to assume that future civilisations have abandoned that barbaric old practice.

If you are planet-hopping, unless you are in your home system, you are not really a member of the society where you commit the crime. They are not really interested in bringing you "back" into their lawful society since you were not a member of that society anyway, but just a transient traveller/merchant. So rehabilitation is not an issue.

Reparation can be handled by the system government where the damage happened, or — as in Elite Dangerous — you are simply required to be insured; if your ship gets destroyed, insurance pays for a new ship. Also in the Elite-verse chances that you will be rescued from a ship-wrecking disaster are very good. And if you are not... hey, who is every going to know, hm?

Prevention and Protection are both handled by the mere fact that you have run away from the system; you cannot do anything bad to anyone if you are not there.

And if you would return to the system... well... let us just say that the hunt is on. If you are a criminal in a system, anyone and everyone is allowed to use you as their personal target shooting practice.

• Nice answer, but your explanation of Prevention and Protection seems to deal only with offenders who already have a criminal history in a given jurisdiction. How would it address the first-time offenders (in a given jurisdiction) like somebody trying to kill someone, or steal something valuable and running away afterwards, with no intent to return? – Danijel Aug 22 '18 at 18:29
• You are misunderstanding the purpose of retribution. It's not about society taking vengeance. It's about preventing the victims from taking vengeance by taking that role from them. Somehow, I doubt that there will ever be a society so developed that victims won't want the people to hurt them to hurt in turn. Pretending that there will is dangerously naive and likely to result in severe problems in any society that tries to implement it. – Brythan Aug 23 '18 at 1:30
• @Danijel Prevention is normally called deterrence. We promise punishments so that people do not commit crimes. Protection, normally called incapacitation, is where we jail the criminals away from the rest of society or otherwise take away the capacity to commit the crime. As noted, exile is pretty effective at keeping someone from committing crimes in the original location. It both deters (people who might commit a crime don't to avoid being exiled) and incapacitates (people who flee can't commit more local crimes). It is less effective universally (outside the current jurisdiction). – Brythan Aug 23 '18 at 1:36
• @Brythan This is fiction. Even today state sponsored/aided retribution is very low on the list when it comes to legislation. Prevention/deterrence and rehabilitation is much more important. – MichaelK Aug 23 '18 at 3:56
• @Brythan And just to point out: no, I did not at all misinterpret retribution. I am well aware that victims have had the the right to inflict revenge on anyone that has wronged them has been taken away in order to prevent blood feuds, and that the justice system has taken over that role so that people will at least feel that they will get some bit of retribution for the slight or injury that was inflicted upon them lest they go out and take care of it themselves. What I am saying is that this part exists mostly due to grandfathering and that other priorities dominate today. – MichaelK Aug 23 '18 at 13:27

I assume we are ignoring how FTL in normal space would either end very badly for the ship, or result in the ship disappearing for millions of years. Whatever technology that is allowing the laws of physics to bend, would probably leave an after effect that could be tracked.

Might not need to go full star trek "Warp signature" or "ion trail" but you could make it easy for law enforcement to track a ship through virgin untraveled space because the disturbance is so obvious. But if the criminal sticks to shipping lanes or well traveled space, then they are next to impossible to track.

This affect might cause law enforcement to block common lanes to try and force a criminal to go "off roading" and show up on a scan.

You could even add an extra restriction that if you travel off the well worn space highways, your fuel...(light-yearage?) drops and you can't go as fast or as far.

Extreme Electronic Surveillance + Enforcement (EESE)

1. Manufacturing of a 3D print-capable matter synthesizer requires a license
2. Necessary condition for obtaining a license is to embed EESE technology in each manufactured unit
3. Surveillance: EESE-enabled printers phone home every time something is printed (assuming they're near enough, otherwise they just buffer until), to alert authorities about possible contraband printing
4. Enforcement: Law enforcement authority can order a specific EESE-enabled printer to print anything they choose. Including, but not limited to, a killbot swarm, or a nuke with short fuse. Commands for EESE-enforcement will be broadcast in any civilized system, so if the perpetrator ever gets back anywhere near the civilization as a whole, they're in trouble

As a result of EESE, a criminal has the option of never coming back near civilization again, or limiting himself to second-rate black market 3D-printers. The limited quality of black market printers means that the perp must come back to civilization every once in a while, for the more advanced spare parts, and risk getting caught.

edit: Aside from this somewhat silly example, the point is, that any technology indistinguishable from magic, could be or become subverted by law enforcement.

• Welcome to Stack Exchange! If you haven't already, please take the tour and visit the help centre – Aric Aug 22 '18 at 13:07

Some may tell you to let these criminals run away. That's fine if you are a happy and friendly democratic power. But if you are any kind of dictatorship, willing to keep your society safe from rebels, or perhaps HERETICS, in any case dangerous people, then you can't allow them to escape so easily.

But why would you need a police, when you could use instead space knights and bounty hunters ? Your space police will maintain the border and make everything it can to pull out anyone trying to enter your empire/federation/whatever you want. Your police will catch who wants to enter the border, but it would cost a lot to have dedicated space forces to track criminals. You'd have to pay an insane number of people to search for years, while having the administration running in the background and costing a lot too !

On the other hand, a lone human can do the same job as an investigator without a pay and administrativ burden if there's a prime to earn. Or even better, if there is fame to earn ! Or perhaps are the people you send to chase criminal motivated by faith, and thus just fanatical ? Then they don't need anything.

Anyway, criminals even though they can live in autarcy will seek contact with humans and the outside world. Very few people can live totally cut from the rest of the universe, and one day or another, they will contact someone, or go to an inhabited system. And there, a skillfull investigator will find any trace the criminals left behind, and will track them and bring them to justice.

Of course your space police can assist these people. It can have some remote bases ready to send task forces whenever a criminal's lair is found. It could use dedicated observation posts, to scan for offworld signals passing by and to monitor even the slightest power surge in space. And it could give informations and help to your bounty hunter/knights/whatever to help them capture these criminals.

All of this would cost less than a full fledged police force roaming the whole galaxy to find criminals that could live anywhere, your police forces could much easily concentrate on important tasks like border protection duty, or investigating on underground operations on your planets/colonies.

• Your formatting is weird and off-putting. Why ARE you BOLDING and capitalizing random words in your POST? – HopelessN00b Aug 21 '18 at 15:40
• @HopelessN00b ThaT's rude Dude re4lly to MoCk my WrItTing Styl3. I capitalized only one word, and bold some points that seem important to highlight. As if it was important, that answer suck, no need to put salt on the wound. – Kaël Aug 22 '18 at 7:34

Easy-peasy. Any form of faster than light travel by definition is also a time machine. Just google for ftl and causality violation. Here's an example link.

If the authorities really care, they can record the incident and send a government ship on a round-trip that has the list of incidents and provide the details to itself in plenty of time. For each incident on the list, they can be there waiting at the scene of the crime or at the miscreant's ship.

• Any form of faster than light travel by definition is also a time machine. Not true if you allow for a preferred reference frame, which is explicitly stated in the question alongside with no violation of causality (i.e. no time travel to past). – Danijel Aug 21 '18 at 20:15

Considering there are more than 100 nations on Earth, I don't see any reason to assume any jurisdiction will span much more than they do today. Maybe at planet level in smaller colonies, considering how easy is to travel in-world and the cultural impact of having all settlers coming from the same place. Probably not on Earth, nor in the few first and lasgest colonies.

If the criminal is hiding in uncharted worlds, he is out of jurisdiction and nobody will bother to look for him. If he is hidden in a civilized world, extradition treaties applies as usual.

Sure if the "crime" committed is somehow of political nature, or too important, like major terrorism, you may want to divert some state resource to track and assassinate, like North Korea did with Kim Jong Un's brother and USA with Osama bin Laden. But is the there is no politics involved, such pursuits are unlikely.

### News

Send out information about criminal flight with every FTL ship that leaves your planet. And check all incoming people to verify that they are not returning criminals. Make it illegal for a fleeing criminal to land on your planet. Assuming every planet does this, the net effect is that a criminal is unwelcome on every planet.

In reality, some planets will choose to be more accepting of such criminals. So criminals will concentrate on those planets. Either the criminals normalize into legal activities or they don't. If they normalize, they aren't much of an issue. Sure, they got away with murder (or whatever crime), but they can never see their friends or families again. They are both incapacitated (can't commit crimes in the original jurisdiction) and punished enough for deterrent and retribution purposes. If they don't rehabilitate, their new planet won't let them stay.

Those who don't normalize have to find new criminal enterprises. But then they become criminals on the new planet. Either they leave or submit to punishment. Eventually, they go to just a few jurisdictions, and you have a concentrated criminal enterprise, which is vulnerable to space fleets, etc.

Pirate cities (concentrated criminal enterprises) also aren't particularly nice places. They have a bunch of murderers at them, which leaves the people there highly vulnerable to murder. And if you commit murder and the victim has more friends than you do, chances are you get murdered in turn. While they aren't jails, they have much of the same social structure. You're free from guards but even more subject to being ruled by charismatic but brutal leaders.

For some crimes, extradition may be possible. Bounty hunters may watch the criminal news for people with rewards that will pay for collecting them and taking them back. Or maybe they just repossess the ship and take it back, assuming the criminal stole the ship in the first place.