The problem is that you can't take away people's homes from those who are not connected with the offence (i.e. other family members). However, you could use the Proceeds of Crime Act to take assets away if you can separate them to specific individuals and connect the assets to specific crimes -...
Once people have a permanent address it's much easier to start enforcing the law on them as we should equally with everyone. It's not a quick process and I'm not pretending I'd like to live next people who behave in that demonstrable anti-social way - but it's a start.
Making it a criminal...
The problem really is that travellers have a lifestyle that isn't compatible with modern society. Post motorised transport the idea of a travelling community is very different from before that time.
I know several places where travelling communities have created more permanent settlement...