so... your example presumes some things that wouldn't exist in any kind of anarchy that i would recognize as such, namely capitalism (or at least money--open question if money could exist at this point without capitalism) and borders (not to mention whatever body is granting bankruptcy!).
but say we assume that your example is mostly for the purpose of explaining the logistics of what you're asking about (ie people who do bad things to others and then leave the area) then leaving aside your specifics, transgression-with-travel would be dealt with the same way in principle as other transgressions. that is, if people cared enough to search them out and find them, and had the resources to do so, then they would. if they didn't, they wouldn't. if people had the capacity to inform those where the transgressors had traveled, then presumably the word would get around and the transgressors would find their options curtailed eventually.
part of the challenge of an anarchist vision is considering how different relations would be when there is no longer a body of experts (either in rules or in violence) to appeal to. anarchists of course recognize that that certainly cuts off some options, but we believe it opens up a lot more, and better, ones.