A Maryland appeals court has postponed the trial of a police van driver charged with second-degree murder in death of Freddie Gray.

Jury selection was delayed Monday so that the Maryland Court of Special Appeals can address whether another Baltimore officer can be compelled to testify against Caesar Goodson.

Baltimore Circuit Judge Barry Williams said prosecutors asked for a delay in the trial and Goodson’s lawyers objected. However, he said that request was moot because the appeals court — the second-highest in the state — had already ordered a delay.

Williams ruled last week that William Porter, whose trial ended in mistrial last month, must testify against Goodson despite Porter’s claim that he has a right not to incriminate himself. The court of special appeals last week temporarily blocked the ruling while its judges consider whether to uphold that decision.

Gray died in April from a broken neck he suffered during a van ride.

Goodson was with Freddie Gray for every second of his 45-minute trip from the site of his arrest to the Western District police station, where Gray arrived critically injured and unresponsive. But Goodson’s account of what happened on that day remains a mystery: He is the only one of six officers charged in Gray’s death not to speak to investigators.

The trial was to offer the public its first chance to hear Goodson’s side of the story.

He faces the most serious charge of all — second-degree murder, which carries a maximum sentence of 30 years in prison. To be convicted, prosecutors must prove that Goodson was so callous in his disregard for Gray’s life that he deliberately allowed him to die.

After Porter’s case ended in a mistrial, the stakes for Goodson’s trial are even higher in a city still on edge from the rioting and unrest in April.

Gray’s death in April exposed the deep divide between the public and the police in Baltimore, and became a national symbol of the Black Lives Matter movement.

Prosecutors say the officers should be held accountable for Gray’s fatal injuries because they didn’t buckle him into a seat belt, nor did they call an ambulance when he indicated he needed medical attention. Goodson, they say, bears the most responsibility because as the wagon driver, Gray was technically in his custody.

Prosecutors have revealed little about the case they plan to present against Goodson, who is also black. But in a pretrial hearing last week they said they would call a witness who specializes in “retaliatory prisoner transport practices,” indicating they intend to bring up the possibility that Gray received a “rough ride” in the van.

During the hearing, defense attorneys argued that prosecutors had introduced “a new legal theory or area of testimony at the proverbial eleventh hour.” The witness is Neill Franklin, a former Baltimore police officer and Maryland state trooper.

During his own trial Porter told jurors that it was Goodson’s responsibility to buckle Gray into a safety belt, and that Gray was unrestrained throughout the entire wagon ride.

Porter also said he told Goodson that Gray wanted to go to a hospital, but Goodson ignored his suggestion.

Defense attorneys and prosecutors can’t comment on the case because they are under a gag order.

(AP)