Baltimore's top prosecutor stood at the top of a sweeping staircase last spring and declared that six police officers would be held accountable for the broken neck of a 25-year-old black man whose death in custody set the city on fire.

State's Attorney Marilyn Mosby was unequivocal that day: Freddie Gray, she said, "suffered a severe and critical neck injury as a result of being handcuffed, shackled by his feet and unrestrained inside of the BPD wagon."

A year and three trials later, the state has yet to secure a conviction. One officer was acquitted, another's trial ended in a hung jury, and in closing arguments Monday, prosecutors all but abandoned their central theory — that Officer Caesar Goodson intended to give Gray a "rough ride" after he tried to run from police.

Goodson, who is also black, declined to speak with investigators and did not take the stand. A camera that might have shown the fatal injury inside the van was broken, and lacked the capacity to record images anyway.

No security videos along Gray's 45-minute odyssey to the nearby police station captured any sudden stops or movements that would have clearly slammed an unbuckled prisoner against the van's metal benches and walls. No witnesses testified to this, either.

"There was no good reason for the officer to repeatedly fail to seat belt Mr. Gray except to bounce him around," Chief Deputy State's Attorney Michael Schatzow said as the trial began.

But in closing, prosecutor Jan Bledsoe didn't mention a "rough ride," and instead told the judge it was Goodson's inaction — his failure to call for help or buckle Gray into a seat belt — that shows his intent to do him harm.

"Officer Goodson never calls a medic, he never takes Freddie Gray to a hospital," she said. "He breached his duty and because of that breach, Freddie Gray's life was shortened."

Defense attorney Matthew Fraling sought to exploit the discrepancy, comparing the state's case to a game of "Three Card Monty."

"The state came into this matter on the proverbial high horse of a 'rough ride,'" he said. "They have failed to cobble together any type of case with reasonable inferences, let alone evidence."

In rebuttal, Schatzow said, "this is not a card game."

Gray's death was "a completely unnecessary homicide of a young man who was killed by the inaction of Caesar Goodson," he declared.

The judge asked Schatzow to explain the state's rough ride theory.

"Are you aware there has to be intent?" Williams asked. "The state brought it into the world. You're the one who said it. What did you show" to prove it?

Schatzow repeated that the lack of a seatbelt proves Goodson "intended for there to be consequences."

The judge alone will decide Goodson's fate, by Thursday he said, after the officer declined a jury trial. And he seemed skeptical that he had seen the intent necessary to support a murder conviction.

Even Schatzow pulled back on alleging that Goodson intended to kill Gray. He accused Goodson of making one of the stops out of concern that he'd gone too far in inflicting injuries. "The fact that he stopped shows there was a consequence greater than he anticipated and he had to figure out what to do," the prosecutor said.

The judge countered that the stop could be seen as concern for Gray's well-being.

Goodson, considered by Mosby to be the officer most responsible for Gray's death, also is accused of manslaughter, assault, reckless endangerment and misconduct in office.

The police officers who caught up with Gray outside a public housing complex in West Baltimore on April 12, 2015, initially handcuffed him behind his back and sat him down on the wagon's bench, but didn't buckle him in.

Goodson drove two blocks, then stopped so that officers could shackle Gray's legs as well after they said he was acting up inside. This time they slid him onto the floor, head-first and on his belly.

The van stopped three more times before Gray arrived unconscious at the police station — twice to check on his condition, then a final detour to pick up another arrestee.

Prosecutors say Gray suffered his spinal injury somewhere between the second and fourth stops when he got up from the floor and, unable to steady himself, suffered blunt force trauma that medical experts have likened to a diving injury.

But Goodson's attorneys said Gray wasn't showing any signs of injury until the very end. Officer William Porter, who faces a retrial in September, said he and Goodson saw Gray's requests for medical help as only a ploy to avoid jail.

Goodson's trial exposed deep mistrust between prosecutors and police.

Schatzow told the judge he tried to have the lead police detective Dawnyell Taylor removed for "sabotaging the investigation." Taylor countered that she doubts the integrity of prosecutor Bledsoe, whom she accused of withholding evidence.

Schatzow then suggested Taylor falsified notes to make it appear that the medical examiner initially considered Gray's death to be accidental — a finding he said Dr. Carol Allen was pressured by police to declare before ruling it a homicide.