On the Core Worlds, carrying an illegal weapon is punishable by a fine, and hard labor. Murder, punishable by personality wipe and exile.
One the Core worlds, three species have full citizenship: Humans, Glahn, and the Ishantra. Everyone else is a second class citizen, and being a convicted criminal almost always results in the same penalty.
On the rim, law enforcement is much more relaxed, so *everyone* does their part to keep violence from escalating.
This includes licensing fees for "street" level weapons, custom fees and tariff's for bringing restricted tech, and confiscation until departaure for miltary grade weapons.
Most places frequented by the criminal tend to have door scanners that are very difficult to defeat (and most miltary tech just isn't designed to).
In addition to detecting weapons (and armor), these scanners are capable of detecting serial numbers on any cyber of sufficient mass.
And it's *expensive* to hire someone to flash new numbers.
On the rim, dozens to hundreds of alien races swarm plents, cities, and outposts. The only thing that matters is if you're recognized as local... or not.