It was one in a series of high-profile deaths of black suspects at the hands of police that stoked a national debate in the United States on police tactics and the treatment of minorities.
Prosecutor Marilyn Mosby had stunned Baltimore when she filed charges against six police officers after 25 year-old Freddie Gray had his spine severed while being transported in a police van.
He died of his injuries a week later, sparking riots across the city and adding fuel to a national debate over police treatment of African-Americans.
Ms Mosby brought charges ranging from second-degree murder to manslaughter and reckless endangerment.
But she's been unable to win a conviction in any case that's come to trial.
Three officers were found not guilty and a fourth case last week ended in a mistrial.
So Ms Mosby has announced she will not proceed with the cases against the remaining officers.
"Without real substantive reforms to the current criminal justice system we could try this case a hundred times, and cases just like it, and we would still end up with the same result. As a mother, the decision not to proceed on these trials, on the remaining trials, is agonising. However as a chief prosecutor elected by the citizens of Baltimore I must consider the likelihood of conviction at this point."
But Ms Mosby tenaciously defended her decision to file the charges.
She says her team stands by a medical examiner's conclusion that Freddie Gray's death was a homicide.
"The decision to prosecute six police officers was not and has never been an indictment on the entire Baltimore police department. Although some have tried to invalidate my family's long-standing service as public officers, I know first-hand the sacrifices, the dedication, the commitment it takes to protect and serve our communities. For those that believe that I'm anti-police it's simply not the case: I'm anti-police brutality."
Ms Mosby has blamed the lack of convictions on "a reluctance" and "an obvious bias" among some officers investigating Freddie Gray's death.
Those claims have been roundly rejected by city officials ranging from the mayor of Baltimore to the head of the police union, Gene [jeen] Ryan.
"Justice has been done. The comments made today about our officers by Ms Mosby were outrageous and uncalled-for and simply not true. The detectives assigned to the case conducted a very thorough investigation into the tragic death of Freddie Gray but the state's attorney simply could not accept the evidence that was presented. She had her own agenda."
Ms Mosby has also come under fire from the US Republican presidential nominee, Donald Trump.
While praising the police officers for persevering through four trials in seven months, he's called Ms Mosby "a disgrace to the world of prosecutors".
"I think she ought to prosecute herself. I think it's disgraceful what she did and the way she did it. And the news conference that she had where they were guilty before anybody even knew the facts. And I give a lot of respect and a lot of credit to those police officers who probably could've made a deal; they stuck it out and she had no chance. Don't forget, she prosecuted the best case, what she thought were her best cases, first."
But through it all Ms Mosby did have unwavering support from Freddie Gray's family, including his stepfather Richard Shipley.
"We are pissed about the decision of the trials in the outcome of all the trials that have happened here in the city. We are very proud of the prosecutors who handled the case and did their best to their ability. We stand behind Marilyn and her prosecuting team, and my family is proud to have them represent us."
The decision means no-one will be held criminally responsible for Freddie Gray's death but prosecutors say the case has led to changes in Baltimore's police department.
Thea"som agency has reconfigured its police vans and fitted officers with body cameras.
It's also updated its "use of force" policy which, in time, could help remedy a police force long plagued by accusations of racial bias.
