Should the father's comments have been enough reasonable suspicion to arrest her, or at least search her for firearms and confiscate them, given her threat leve

Should the father's comments have been enough reasonable suspicion to arrest her, or at least search her for firearms and confiscate them, given her threat level to society? Not from the information in this article. That would mean any adult who gets upset, and goes on a roadtrip without telling their family, could get arrested. If the missing persons report noted that she could be dangerous, then that's a different story.