The rationale behind criminalizing disorderly conduct rests on the belief that a disorderly person can provoke violence in others. Given that an inherent part of police work involves being in the presence of distraught individuals, and given that police officers are trained to maintain order, the Court concluded that police should be the least likely to be provoked [by a 58-year-old professor who walks with a cane]. Therefore, police presence alone does not satisfy the public element.Via The Massachusetts District Attorneys Association.*
"Tumultuous behavior" is right up there with "aggravated mopery," although it's open to discussion which best describes falsely attributing information about the suspects' race to the 911 caller.
* a.k.a. law enforcement officers.