How do you stop people killing each other in the short term?
Unfortunately you can’t in a human rights scenario. The ultimate short term solution is simply to execute all the know gang leaders and kingpins. Will be a lot of years off before we get to judge dredd stage. A more humane approach is to round up the know kingpins and lock them away for a very long time as a deterrent to the scroutes that worship them. Then everything will descend into anarchy . It also won’t matter somebody else will simply take over the ‘turf’.
There is no solution long or short term, man will eradicate themselves anyway. The situation is too far in the gutter. Stay in school , get a good education so you can live in gated communities and wealthy areas is the only solution.