BALTIMORE — With no witnesses or video inside the metal compartment of a police van, it’s likely no one will ever know what snapped the neck of Freddie Gray, a 25-year-old black man left handcuffed and shackled but unbelted on his trip to the station.

What is certain is that six police officers criminally charged in his death were the last to see him uninjured. But none blamed a fellow officer, and the driver of the van, Caesar Goodson, was acquitted of murder and all other charges Thursday after he consistently refused to talk.

With no convictions after three trials so far, the judge presiding over all the cases declared that he has yet to see evidence proving any of the officers committed a crime.

For a citizenry desperate for fundamental changes in the culture of a police department under federal investigation after allegations of decades of abuse, the question remains: How can nobody be held accountable for the death of a young black man whose only apparent transgression was his attempt to run from a police patrol in his neighborhood?

“It’s a matter of fact that he was alive when he got in the van. It’s a matter of fact that his spine was severed,” said Black Lives Matter activist and former mayoral candidate DeRay Mckesson. “Six people contributed to that.”

Goodson and the other officers may be not guilty in a court of law, but “in the street we see it as criminal, and we see that our loved ones are dead,” said Baltimore’s NAACP president, Tessa Hill-Aston.

Prosecutors said Goodson, who was behind the wheel of the transport van and the only officer to be with Gray at each of the six stops along the 45-minute journey from the site of his arrest in Sandtown-Winchester to the Western District station house, was criminally negligent when he failed to buckle Gray into a seat belt and chose not to call a medic after Gray indicated that he wanted to go to a hospital. The state also floated the theory that Goodson gave Gray a “rough ride,” leaving him intentionally unrestrained to bounce him around the metal compartment and cause injuries.

Baltimore Circuit Judge Barry Williams didn’t deny that Gray was fatally injured inside the police van, but he dismissed the charges because the state failed to provide evidence or witnesses to support the claims.

“Here, the failure to seat belt may have been a mistake or it may have been bad judgment,” he said, “but without showing more than has been presented to the Court concerning the failure to seat belt and the surrounding circumstances, the state has failed to meet its burden to show that the actions of the defendant rose above mere civil negligence.”