A US grand jury has indicted all six officers charged over the death of Freddie Gray, who died of injuries suffered in police custody in Baltimore.
The decision allows the state attorney to press ahead with the most serious charges despite criticism that she was part of an “overzealous prosecution”.
People in Baltimore protesting the death of Freddie Gray.
The indictments are similar to the charges state attorney Marilyn Mosby announced three weeks ago after the incident that sparked major rioting in the city.
The charges ranged from second-degree “depraved heart” murder to assault.
Lawyers for the officers have said in court documents that they are the victims of an “overzealous prosecution” riddled with personal and political conflicts of interest.
At a minimum, they said, Ms Mosby should be replaced with an independent prosecutor.
Lawyers for the six said Ms Mosby should be replaced with an independent prosecutor because she had a personal interest in calming unrest in the city and because her husband is a city councilman who represents the areas most affected by upheaval.
Mr Gray suffered a critical spinal injury on April 12 after police handcuffed, shackled and placed him head-first into a van, Ms Mosby has said. His pleas for medical attention were repeatedly ignored.
His death a week later spawned protests that twice gave way to violence and looting.
Two officers, Edward Nero and Garrett Miller, were indicted on second-degree assault, reckless endangerment and misconduct in office for “failure to perform a duty regarding the safety of a prisoner” and for an illegal arrest, Ms Mosby said.
Caesar Goodson, who drove the van, faces manslaughter and a second-degree “depraved heart” murder charge, as well as misconduct in office and second-degree assault.
Sergeant Alicia White, Lieutenant Brian Rice and Officer William Porter are charged with manslaughter, second-degree assault and misconduct in office. They also face reckless-endangerment charges.
Nero, Miller and Rice are white, and Goodson, Porter and White are black.
Mr Gray’s death became a symbol of what protesters say is a pattern of police brutality against African-Americans in Baltimore.
After the death, the Justice Department announced a civil rights investigation of Baltimore Police Department to search for discriminatory policing practices and examine allegations that officers too often use excessive force and make unconstitutional searches and arrests.
According to court documents, Mr Gray made eye contact with a police officer and took off running. He was apprehended two blocks away and arrested for possession of a knife that Miller wrote in charging documents is illegal under a city ordinance. Ms Mosby said the arrest was unlawful because the knife is legal under state law.
None of the officers secured Mr Gray’s seatbelt in the van, a violation of police policy. Soon after he was placed in the van, Goodson made a second stop during which Mr Gray was secured in leg irons because he was “irate”, police said.
After a ride that included two more stops, including one to pick up a second passenger, the van arrived at the Western District police station. By that time, Mr Gray was non-responsive.