Officer Caesar Goodson, one of six Baltimore city police officers charged in connection to the death of Freddie Gray, leaves the courthouse after the second day of his trial, Friday, June 10, 2016, in Baltimore. (AP Photo/Jose Luis Magana)

BALTIMORE (AP) — A trial will move ahead on all charges against a Baltimore police officer charged in the death of a Black prisoner whose neck was broken in a police transport van, but the judge said Thursday he has questions about the most serious charge at the center of the state’s case.

Judge Barry Williams said the charge of second-degree “depraved heart” murder was “a closer call” than the others. Yet after Officer Caesar Goodson’s attorneys moved to dismiss all charges, he declined.

Goodson’s attorneys made the request after prosecutors rested their case Wednesday.

Defense attorney Andrew Graham contended Thursday that prosecutors had failed to prove Goodson, the van driver, gave 25-year-old Freddie Gray a “rough ride” as Gray was handcuffed and shackled on the floor. Graham noted that one of the state’s key witnesses, an expert on police policy, couldn’t say for sure whether he saw evidence of a rough ride — police lingo for putting a prisoner in a police wagon without a seatbelt and driving so erratically that he or she is thrown around.

The state “hasn’t introduced any proof at all,” Graham told the judge.

But prosecutors cited Goodson’s failure to get Gray medical attention and to seatbelt him in the van, despite multiple opportunities at several stops.

“It’s at least five times, your honor,” Michael Schatzow, chief deputy state’s attorney said, referring to the number of times Gray could have been seat-belted.

Goodson, 46, also faces manslaughter, assault, misconduct in office and reckless engenderment charges.

His attorneys will now move forward with his defense on the sixth day of the trial.

On Wednesday, Williams ruled prosecutors violated discovery rules when they failed to give the defense a detective’s notes that indicate an assistant medical examiner at one point considered Gray’s death might have been an accident. That could contradict earlier testimony from Dr. Carol Allen, who determined Gray’s death was a homicide and not an accident.

The discovery violation comes after Williams asked prosecutors to review their files for evidence they hadn’t disclosed to the defense. The judge had found prosecutors violated discovery rules about information concerning a witness in an earlier case.

“It’s never a good thing when a judge finds the state has committed a discovery violation,” said Warren Alperstein, a Baltimore attorney who is uninvolved in the case but has observed nearly all the legal proceedings. “It’s certainly not good when there are repeated discovery violations, and what’s so significant is that these are discovery violations that are so egregious because there’s an absolute affirmative obligation for the prosecution to turn over any evidence that is favorable to a defendant.”

Prosecutors are still looking for their first conviction, after their first case against another officer ended in a hung jury and their second resulted in the judge’s acquittal of another.

Gray’s death in April 2015 touched off the worst riots in Baltimore in decades.