Same thing was asked about Waco.
Koresh went into town frequently so he could have been arrested on the child abuse charges out in public with no hassle. Further, Koresh offered to allow the ATF to inspect the Davidians' weapons and paperwork long before the siege took place. but The ATF Cowboys wanted their big dog and pony show instead. See, you can't get all "Ramboed Up" if the suspects cooperate and you find no evidence.