Pennsylvania Statutes Title 53 P.S. Municipal and Quasi-Municipal Corporations § 16621. Officer may require assistance;  may disperse, seize or apprehend rioters;  use of necessary force

If after proclamation made as aforesaid, or if the said marshal or other officer of police so authorized as aforesaid, shall attempt to make such proclamation, and shall be prevented by force from making the same, then after such attempt made, if such persons so unlawfully, riotously or tumultuously assembled, shall continue together and not disperse forthwith, then it shall be lawful for the said marshal and police, and such other person or persons as shall be commanded to assist under said marshal, who is hereby authorized to command all ward constables, and citizens of age and ability to assist him therein to disperse, seize or apprehend such persons so unlawfully, riotously or tumultuously continuing together, after proclamation made or attempted to be made as aforesaid, and they are hereby required so to do, and to use all necessary force and means whatsoever for said purpose.