D.C. Code § 2-209.04: Reciprocal police mutual aid agreements — Supervision of non-District police in District; enforcement of District laws by non-District police.

The Mayor of the District of Columbia shall be responsible for directing the activities of all policemen and other officers and agents coming into the District pursuant to any such reciprocal agreement, and the Mayor is empowered to authorize all policemen and other officers and agents from outside the District to enforce the laws applicable in the District to the same extent as if they were duly authorized officers and members of the Metropolitan Police force of the District of Columbia.