How do i know if an ault case is criminal? if it's not, can da case b dissmissed if plaintiff doesn't show?

my dad was drunk and was screaming at my brother(his step son) and chasing him on the street. my brother called the cops and when they got there, they found a screwdriver on my dad's pocket. he got arrested and has order to court. he was charged with ault and was not required to post bail. i was wondering if the charge can be dropped if my brother did not show up. help. please.