The Justice Department slammed the Baltimore Police Department in a new report, saying officers routinely use excessive force against blacks and targets the African-American community for enforcement.

Those "longstanding systemic problems" have "eroded the mutual trust" between the department and the black community, the report released Wednesday found.

The report said the agency found "reasonable cause to believe that [the Baltimore Police Department] engages in a pattern or practice of conduct that violates the Constitution or federal law."

The report is the culmination of a year-long investigation into the department, the eighth-largest police force in the nation.

Physical force by officers also is used against the mentally disabled, the report found, adding that black pedestrians and drivers are disproportionately searched during police stops.

In a statement ahead of the release of the report Wednesday morning, Baltimore Mayor Stephanie Rawlings-Blake said the police department's "Use of Force" policy, as well as 25 other key policies, have been revised following the report.

"Much remains to be done. Change will not happen overnight. But our efforts have started the necessary process of change," she said, adding that over the next few months the city "will put in place a concrete plan for change and a new culture."

Vanita Gupta, head of the Justice Department's Civil Rights Division, said at a Wednesday press conference that everyone agreed the Baltimore Police Department needs "sustainable reform."

"These violations have deeply eroded the mutual trust between the Baltimore Police Department and the community it serves," Gupta said, adding that the problems in the department "didn't happen overnight or appear in a day."

In outlining "longstanding systematic" problems within the department, Gupta said Baltimore's black community "bore the brunt" of unconstitutional policing.

By working together in the future, Baltimore can become a city that "protects the rights, safety and dignity of all," Gupta added.

Rawlings-Blake at the press conference said she is confident Baltimore can become a national model for police, urging reforms happen as quickly as possible.

Baltimore Police Commissioner Kevin Davis said the report — which he said he is "very, very concerned" about — is an indictment of those who breached "fragile trust." He added that many of his officers are outraged at the report's findings.

Officers who "blatantly disregard" people's rights "should not be comfortable, because we aren't going to tolerate it," Davis said.

"Change takes time. Change takes commitment. Change takes trust. We will get there," Davis added at the Wednesday press conference.