Baltimore prosecutors have dropped all remaining charges against the police officers involved in the death of Freddie Gray, bringing an end to the case that has spurred mass protests throughout the country for seven months.

The sudden decision on Wednesday means there is unlikely to be any accountability in Gray's death, as it follows several acquittals for three other officers charged in the case.

Baltimore State's Attorney Marilyn Mosby said Wednesday that the decision to drop the charges against Officer Garrett Miller—who physically arrested Gray—Officer William Porter, and Sgt. Alicia White was "agonizing," but that there was a "dismal likelihood" of securing a conviction.

"After much thought and prayer it has become clear that without being able to work with an independent investigatory agency from the very start, without having a say in the election of whether cases proceed in front of a judge or jury, without communal oversight of police in this community, without substantive reforms to the current criminal justice system, we could try this case 100 times and cases just like it and we would still end up with the same result," she said.

The Baltimore Sun reports:

Officer William Porter's trial ended with a hung jury and a mistrial in December, before [Circuit Judge Barry G. ] Williams acquitted Officers Edward Nero and Caesar Goodson and Lt. Brian Rice at bench trials in May, June, and July, respectively. [....] The decision Wednesday to drop all charges came during what was expected to be a contentious hearing surrounding the prosecution's ability to proceed with Miller's trial without using anything he said on the witness stand in Nero's trial against him.

Gray, 25, died after his spine was severed during an arrest in April 2015. Footage of officers dragging him into the back of a police van went viral, sparking widespread outrage.

The news devastated those who hoped Mosby, who has made passionate demands for justice in the case, would be able to convict.

"The system we allow has failed him," tweeted director and activist Ava DuVernay. "Our shame."

Journalist Shaun King also wrote: "To be honest, I'm beyond words with the #FreddieGray case right now. The brother arrived at the hospital in a coma with a severed spine." In a separate tweet, he called the decision "infuriating."

Tessa Hill-Aston, the president of Baltimore's NAACP chapter, told the New York Times on Wednesday, "I personally wanted them to go through with it, even if it was a no-win situation." She said justice had not been served "as far as people on the streets, and people seeing that the police officers got away with murder."

"Because at the end of the day right now," she said, "Freddie is dead and someone caused his death."