The mayor called on federal investigators Wednesday to look into whether this city’s beleaguered police department uses a pattern of excessive force or discriminatory policing.

Mayor Stephanie Rawlings-Blake said even though complaints of excessive force and lawsuits alleging misconduct our down over the last few years, “we all know that Baltimore has a fractured relationship with community.”

The mayor’s request came a day after new Attorney General Loretta Lynch visited the city. The mayor said Lynch understands the urgency of her request.

Baltimore saw days of unrest after Freddie Gray, a black man, was taken into custody and suffered critical injuries. He died a week later. People threw bottles and bricks at police during a riot on April 27, injuring nearly 100 officers. More than 200 people were arrested as cars and businesses burned.

The Justice Department is already investigating whether Gray’s civil rights were violated, and six officers face charges in the arrest and death, ranging from assault to second-degree murder.

The new investigation the mayor called for is similar to one was done in Ferguson, Missouri, following the shooting of an unarmed, black 18-year-old man by a white police officer.

Such wide-ranging investigations look for patterns of discrimination within a police department. They can examine how officers use force and search and arrest suspects.

At the time the Ferguson inquiry was announced in September, it was described as part of a broader Justice Department effort to investigate troubled police departments and, when pervasive problems are found, direct changes to be made. The department said then it has investigated 20 police departments for a variety of systemic misconduct in the past five years, more than twice the number of cases opened in the previous five years.

The investigations can sometimes result in a settlement known as a consent decree, in which the department agrees to make specific changes, and an outside monitor is appointed to make sure the police force complies with the agreement.

The Justice Department reached a court-supervised agreement in 2012 with the New Orleans Police Department that required the agency to overhaul its policies and procedures for use of force, training, interrogations, searches and arrests, recruitment and supervision. In April, it issued a harshly critical report of the police department in Albuquerque, New Mexico, that faulted the agency for a pattern of excessive force and called for an overhaul of its internal affairs unit.