Nearly a month after the arrest of Freddie Gray in Baltimore, it has been announced that the Department of Justice (DOJ) will launch a federal civil rights investigation into the Baltimore Police Department. Newly appointed Attorney General Loretta Lynch made the announcement at a press conference on Friday, just days after the city's mayor requested the inquiry.

Lynch opened the investigation on the heels of controversy over the death of 25-year-old West Baltimore resident Gray, who died in April from a severed spine sustained while in police custody. Baltimore Mayor Stephanie Rawlings-Blake formally requested that the DOJ carry out the probe on Tuesday, following a private meeting with Lynch.

"Recent events, including the tragic death in custody of Freddie Gray, have given rise to a serious erosion of public trust," Lynch said during the press conference.

The inquiry will examine whether or not a pattern or practice of abuse exists within the Baltimore police force, while looking at contributing factors to excessive force and discriminatory policing. When requesting the investigation on Tuesday, Rawlings-Blake also said the probe will look at whether the department has "engaged in a pattern of stops, searches, or arrests that violate the Fourth amendment."

This decision comes a week after Baltimore State's Attorney Marilyn Mosby announced that Gray's death had been deemed a homicide, and charged six officers in connection with his death — which sparked unrest in recent weeks, with protesters taking to the streets of Baltimore demanding justice, with some demonstrations turning into looting.

In a statement released by the DoJ after the press conference on Friday, Lynch highlighted the fact that the department has carried out dozens of these investigations. SHe encouraged other cities to study previous recommendations and apply them in their own communities.

"We have seen from our work in jurisdictions across the country that communities that have gone through this process are experiencing improved policing practices and increased trust between the police and the community," Lynch said in the statement. "Ultimately, this process is meant to ensure that officers are being provided with the tools they need - including training, policy guidance and equipment - to be more effective, to partner with civilians and to strengthen public safety."

Throughout the investigation the Justice Department will consider relevant information, looking at both efforts made by the Baltimore police and community experiences and views. Authorities will also interview police officers and local officials, while gathering information from stakeholders in the criminal justice system like public defenders and prosecutors. The DOJ stressed in the statement that so-called "pattern or practice investigations" of police departments don't evaluate individual cases for criminal violations. In the past, the statement noted, similar inquiries have resulted in court-overseen agreements seeking fundamental changes to the policing practices of police agencies.

Earlier this month, the DOJ opened a federal civil rights investigation looking specifically into the death of Freddie Gray on April 21, to determine whether civil rights violations took place during his arrest. The Justice Department launched the probe as protesters took to the streets of West Baltimore, where Gray lived and was arrested, demanding justice.

The department-wide investigation would add to the ongoing DOJ program in the city investigating police brutality through the Collaborative Reform Initiative for Technical Assistance, which was requested by city officials and initiated six months before Freddie Gray's death.