(CNN) -- The Justice Department and Puerto Rico signed a major civil rights agreement Wednesday to reform the commonwealth's very troubled police force.
The pact faces final approval by a federal judge, who will oversee its enforcement.
An earlier Justice Department investigation found numerous problems in the Puerto Rico Police Department, the nation's second-largest, including:
-- Excessive use of force to suppress free speech.
-- Unconstitutional stops, searches and arrests.
-- A failure to investigate sexual assault and domestic violence allegations.
"Although I recognize that complete and lasting reform will not take hold overnight, I'm confident that this agreement lays out a clear path for responding to concerns, correcting troubling practices, safeguarding the rights of Puerto Rican citizens, restoring public trust, and ensuring public safety," Attorney General Eric Holder said in remarks prepared for a news conference.
According to the Justice Department, the agreement with Puerto Rico is among the most extensive agreements involving the police misconduct provision of the Violent Crime Control and Law Enforcement Act of 1994.
The American Civil Liberties Union welcomed the agreement on an issue it highlighted more than a year ago.
"At long last, the government of Puerto Rico will work together with the Justice Department to end the rampant police abuse that has plagued the island for so many years," Executive Director Anthony Romero said in a statement. "We trust that this historic settlement means that Puerto Ricans will no longer have to live in fear of their own police force. A court-enforceable agreement like this ensures that the PRPD will be held accountable if it fails to overhaul its policies and practices."
An ACLU report in June 2012 disclosed evidence of widespread abuses and violations of civil rights by the 17,000-strong police department, saying the force "has run amok for years." The abuse was "pervasive and systemic, island-wide and ongoing," the report said.
The Justice Department announced in December that it reached a preliminary agreement with Puerto Rico. It delayed implementation to allow then-incoming Gov. Alejandro Garcia Padilla the time to review it and suggest possible changes.
Puerto Rico's police force serves almost 4 million residents.