Law Enforcement's Response to the January 6th Events at the Capitol [January 22, 2021] [open pdf - 632KB]
From the Document: "On January 6, 2021, security at the Capitol was breached by people who reportedly sought to prevent Congress from certifying the votes of the Electoral College. Some individuals clashed with law enforcement officers and for several hours occupied parts of the Capitol. At the request of District of Columbia Mayor Muriel Bowser and the U.S. Capitol Police, law enforcement agents from the Department of Justice (DOJ), along with law enforcement officers from the U.S. Park Police, the Metropolitan Police Department (MPD), and law enforcement agencies in Maryland and Virginia, assisted with expelling the occupiers and securing the Capitol. In addition to the damage done to the Capitol, pipe bombs were found near the Democratic and Republican National Committees' offices. A car with 11 explosive devices was found near the Capitol. Some reportedly brought firearms and ammunition onto the Capitol grounds. DOJ is jointly investigating criminal cases stemming from the events at the Capitol with MPD and the Capitol Police. [...] This In Focus describes the jurisdiction and investigatory responsibilities of the law enforcement agencies that responded to the Capitol unrest. It also provides an overview of the authority for federal, state, and local governments in the National Capital Region (defined as the District of Columbia; Montgomery, Prince George's, Arlington, Fairfax, Loudon, and Prince William Counties; and Alexandria) to enter into mutual aid agreements with each other."
CRS In Focus, IF11738
Congressional Research Service: https://crsreports.congress.gov/