After a two-month trial over the NYPD's stop-and-frisk practices, Wednesday was the deadline for final briefs, setting the stage for a ruling on the program's constitutionality at any time.
If U.S. District Judge Shira Scheindlin in Manhattan finds against the city, she is widely expected to name a monitor to oversee reforms.
The Justice Department has until now stayed out of the case. Multiple reports Wednesday said that the department was planning to ask to play an oversight role, but neither the Justice Department nor City Hall would confirm or comment on the report.
No motions from the Justice Department were filed on the federal court website late Wednesday.
Legal and City Hall sources said the Justice Department might merely be planning to file a "friend of the court" brief that provides information on how monitors have worked in other cases involving police departments, without urging the action or asking to play an oversight role.
"We have not seen any papers yet" from the Justice Department, said John McCarthy, a spokesman for Mayor Michael Bloomberg. He added that New York City is the safest big city in the country "thanks to the exceptional professionalism of the NYPD. Their work to cut crime to record lows and take illegal guns off the street has saved thousands of lives."
In June 2012, city officials from three levels of government had asked the Justice Department to consider investigating the NYPD's stop-and-frisk program for overwhelmingly targeting minorities.
The delegation of city, state and federal officials also asked that the agency intervene on lawsuits challenging the police tactic and assist them with legislative proposals to counter the program, including withholding some grant funds.
With Emily Ngo