Once the parents were dead why didn't the bad guys just leave...
Morning would come, they'd get the cops, and that would have been that.
If only the parents were killed, the inheritance would've been shared between the four siblings.
shareWatch the movie instead of playing with your phone next time.
Utah! Get me two.
To be honest, that would have worked. One of the siblings was already dead, so if they called off the attack, they would have divided it among 3 instead of 2 people - not much difference. And that's assuming douche brother didn't die from the arrow in his back.
Most importantly, the risk of being caught would have been much, much lower. Given that things weren't going as planned due to Erin the Head-Basher, they should have considered calling it off.