MPD said the internal investigation will focus on department's "change in the initial classification of the offense," as well as why officers did not arrest Mills.

A Florida congressman is under investigation for an alleged assault in Washington, D.C., an incident report from the Metropolitan Police Department shows. The NBC-owned station in Washington, D.C., is reporting it happened Wednesday afternoon at a penthouse in a luxury apartment building.

Central Florida Congressman Cory Mills is under investigation for an alleged assault, a spokesman for the District of Columbia’s Metropolitan Police Department said Friday. Officers were called to an apartment building about two miles from the U.S. Capitol at 1:15 p.m. Wednesday, according to the police department.