Ok I've figured out how to enable the town PK bug. It's a bit complicated, but it goes like this (all steps must be completed in the same game)
1) Buy 237 stamina potions and drink them. It has to be this exact number or the bug won't work
2) Cube 2 Ber runes to make a Jah
3) Push a chicken from Blood Moor to Blood Raven by walking behind it like this:
That's it, now you can shoot into town and kill anyone you want