A court-supervised agreement announced Tuesday to overhaul the New Orleans Police Department will require the troubled agency to implement the most far-reaching police reforms ever negotiated by the Justice Department.

Attorney General Eric H. Holder Jr. joined Mayor Mitch Landrieu (D) in announcing the signing of a federal consent decree designed to clean up a police force that has been plagued by decades of corruption and mismanagement. The department came under renewed scrutiny following a string of police shootings in the chaotic aftermath of Hurricane Katrina in 2005.

The 124-page agreement spells out a series of strict requirements for overhauling the police department’s policies and procedures for use of force, training, interrogations, searches and arrests, recruitment and supervision.

Holder said the agreement is the most wide-ranging in the Justice Department’s history.

“There can be no question that today’s action represents a critical step forward,” Holder said. “It reaffirms the Justice Department’s commitment to fair and vigorous law enforcement at every level.”

Landrieu estimates that the city will pay about $11 million annually for the next four or five years to implement the reforms.

“There is no problem here that cannot be solved,” he said. “We can and we must change, and we now have a clear road map forward.”

A federal judge must approve the agreement and oversee its implementation.

The Justice Department has reached similar agreements with police departments in Los Angeles, Cincinnati, Pittsburgh, Oakland, Calif., and Detroit. But the scope of this consent decree is billed as the broadest of its kind.