Are you sure if you can let your kids walk alone to school bus and there is no danger lurking around?
Are you confident that the community you are living in is safe?
Better safe than sorry. So, check yourself if there is any offender in your area. There are publicly accessible lists provided by either Department of Law Enforcement or Department of Corrections by each state.
I provided the links below for many states. Many states provide this information for free, no cost at all. You need to pay to access the offenders lists in Arizona ($25) and Arkansas ($0.10 per record).
Links for each state: