BALTIMORE — Baltimore police officers routinely discriminate against blacks, repeatedly use excessive force and are not adequately held accountable for misconduct, according to a harshly critical Justice Department report being presented Wednesday.

The report, the culmination of a yearlong investigation into one of the country’s largest police forces, also found that officers make large numbers of stops — mostly in poor, black neighborhoods — with dubious justification and unlawfully arrest citizens for speech deemed disrespectful.

Physical force is used unnecessarily, including against the mentally disabled, and black pedestrians and drivers are disproportionately searched during stops, the report says.

The Justice Department released a copy of the report in advance of its public announcement at an event Wednesday morning in Baltimore.

The report represents a damning indictment of how the city’s police officers carry out the most fundamental of policing practices, including traffic stops and searches and responding to First Amendment expression. Beyond that, though, it could serve as a blueprint for sweeping changes: The Justice Department is seeking a court-enforceable consent decree to force the police agency to commit to improving its procedures in order to avoid a lawsuit.

The federal investigation was launched after the April 2015 death of Freddie Gray, a 25-year-old black man whose neck was broken while he was handcuffed and shackled but left unrestrained in the back of a police van. The death set off protests and the worst riots in decades.

The report went far beyond the circumstances of Gray’s death to examine a slew of potentially unconstitutional practices, including excessive force and discriminatory traffic stops, within the department.

Federal investigators spent more than a year interviewing Baltimore residents, police officers, prosecutors, public defenders and elected officials, as well as riding along with officers on duty and reviewing documents and complaints.

Among the findings: Black residents account for roughly 84 percent of stops, though they represent just 63 percent of the city’s population. Likewise, African-Americans make up 95 percent of the 410 people stopped at least 10 times by officers from 2010 to 2015.

In addition to pat-downs, Baltimore officers perform unconstitutional public strip searches, including searches of people who aren’t under arrest.

The report also says officers routinely use unreasonable and excessive force, including against juveniles and citizens who aren’t dangerous or posing an immediate threat. Twenty percent of force incidents reviewed by investigators involved someone who was not being arrested for a crime or who suffered from a mental health disability. Force is often used as a retaliatory tactic in instances where officers “did not like what those individuals said.”

State’s Attorney Marilyn Mosby, the city’s top prosecutor, said she expected the report to “confirm what many in our city already know or have experienced firsthand.”

“While the vast majority of Baltimore City Police officers are good officers, we also know that there are bad officers and that the department has routinely failed to oversee, train, or hold bad actors accountable,” she said in a statement.