BALTIMORE (AP) — More than a year after a Black man suffered a broken neck in a police van, the effort to hold six officers criminally responsible for his death collapsed Wednesday when the city dropped all charges in the case that tore Baltimore apart and exposed deep fissures between the police, prosecutors and the people.

A day before another trial was to begin, prosecutors dismissed charges against three remaining officers, blaming police for a biased investigation that failed to produce a single conviction in the death of Freddie Gray.

Gray, 25, was fatally injured in April 2015 while he was handcuffed and shackled but left otherwise unrestrained in the back of the van. His death added fuel to the growing Black Lives Matter movement, set off massive protests and led to the city's worst riots in decades.

Prosecutors suffered blow after crippling blow in the courtroom. A judge acquitted three other officers, including the van driver who prosecutors considered the most responsible and another officer who was the highest-ranking of the group. A mistrial was declared for a fourth officer after a jury deadlocked. Authorities had planned to retry him.

The case took shape soon after the rioting, when Democratic State's Attorney Marilyn Mosby confidently announced the charges atop a sweeping staircase across from City Hall. At the time, she said her decision was based not only on the police investigation but an independent investigation conducted by her office.

"To the youth of the city: I will seek justice on your behalf," she said. "This is a moment. This is your moment."

On Wednesday, she was fiery and indignant as she spoke from behind a podium across the street from the public-housing complex where Gray was arrested. She angrily blamed the outcome on an uncooperative police department and a broken criminal justice system.

Mosby outlined what prosecutors have called sabotage, saying officers who were witnesses were also part of the department's investigative team. She said "obvious questions" weren't asked during interrogations. She alleged lead detectives were slow to provide information and failed to execute search warrants for key text messages. She also accused investigators of creating notes after the case was launched to contradict the medical examiner's conclusion that Gray's death was a homicide.

"We've all borne witness to an inherent bias that is a direct result of when police police themselves," Mosby said.

Prosecutors suffered significant setbacks in nearly every trial presented before Circuit Judge Barry Williams. At several points, the judge berated them for failing to turn over evidence to the officers' attorneys.

At the trial for Lt. Brian Rice, the judge sanctioned prosecutors by preventing them from using Rice's training records as evidence. During the trial for Officer Caesar Goodson, the van driver, prosecutors said Goodson had given Gray a "rough ride," deliberately driving erratically to injure the prisoner. After the state failed to present any evidence to support that theory, prosecutors all but abandoned the notion.

After Officer Garrett Miller testified that he alone arrested Gray outside the Gilmor Homes complex, prosecutors changed their theory of assault in Officer Edward Nero's case, arguing that any officer who arrests a suspect without probable cause could be liable for prosecution.

Prosecutors also sought to have the officers testify against each other, even though some of them had not yet been tried. Defense attorneys fought that idea before the Maryland Court of Appeals, where a panel of judges determined that the officers could be compelled to take the stand as long as a hearing was held to ensure a defendant's comments as a witness were excluded from his or her trial.

Earlier this year, five of the officers filed defamation lawsuits against Mosby. As a result, she refused to answer questions Wednesday.

Two outside police departments are investigating the officers' conduct to help determine whether they should face departmental sanctions.

Also pending is a report from the Justice Department, which has been investigating allegations of widespread abuse and unlawful arrests by Baltimore police as a result of Gray's death. The results are expected soon.

Police Commissioner Kevin Davis said in a statement that Mosby's decision was "wise," and he called on residents to direct their emotions "in a constructive way to reduce violence and strengthen citizen partnerships." He rejected Mosby's accusations that officers involved in the investigation were biased.

Gene Ryan, president of Baltimore's police union, called Mosby's comments "outrageous."

"The state's attorney could not accept the evidence," Ryan said. "She had her own agenda."

Prosecutors alleged that the officers were criminally negligent when they defied a written directive to buckle all suspects into a seat belt in the van. Instead, they were accused of placing Gray head-first into the metal compartment on his stomach. The officers' further erred when they chose not to call for a medic after Gray indicated he wanted to go a hospital, according to the prosecution.

The judge ruled that although the officers may have exercised poor judgment, prosecutors failed to prove that the officers tried to hurt Gray. Without establishing intent, he said, the criminal charges were baseless.

Last year, Gray's family received a $6.4 million settlement from the city.

Gray's stepfather, Richard Shipley, stood next to Mosby as she delivered her remarks.

"We're going to continue to be fighters for Freddie," he said. "We are going to see that new legislation is carried out and new laws that will help this community and other communities. We're grateful that he didn't die in vain."

Since Gray's death, Baltimore police have adopted several reforms, including a revised use-of-force policy and a body-camera program that will require all field officers to be equipped while on the streets. Additionally, the General Assembly approved changes to a Law Enforcement Officers Bill Of Rights, the first updates to the document in decades.

The Gray case never fit neatly into the narrative of white authorities imposing unfair justice on minorities. Three of the officers who were charged are white and three are black. The victim, judge, top prosecutor and mayor are all African-American. At the time of Gray's death, so was the police chief.

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