Officer Caesar Goodson, left, one of six Baltimore City police officers charged in connection to the death of Freddie Gray, leaves the courthouse after the first day of his trial. He was acquitted Thursday of all charges. (Brayan WoolstonAssociated Press)

With two Baltimore officers now acquitted in the death of Freddie Gray, including the only one charged with murder, state’s attorney Marilyn Mosby faces the difficult choice of whether to proceed with four more trials. Her decision almost certainly has to be “no,” and the criticism that she rushed to charge the six officers without sufficient evidence, if only to limit the growing civil unrest in Baltimore, now looks like a valid one. Prosecutorial decisions should be made based on the evidence and the law, not on how they will play on the streets.

Mosby, 36, had been state’s attorney for only four months when she held a press conference on the day she filed charges against the officers, and she admitted there was an extra component to her decision. “To the people of Baltimore and the demonstrators across America, I heard your call for ‘No justice, no peace,’ ” Mosby said in a nationally broadcast statement on May 1, 2015, less than two weeks after Gray died on April 19. “Your peace is sincerely needed as I work to deliver justice on behalf of this young man.” Five of the officers have since sued Mosby for defamation.

“What the state’s attorney promised everybody last May,” said Jeremy Eldridge, a former assistant state’s attorney now in private practice, “it’s pretty much clear it’s unsubstantiated and it’s an outright lie. This is a culmination of all three trials and the judge finally being able to be straightforward about the evidence.”

“They need to cut their losses,” said Tyler Mann, another former Baltimore prosecutor now in private practice, “and say, ‘We gave it our best shot and it’s just not there…This judge is saying, ‘You don’t have it,’ and the undertone is, ‘You don’t have it and you have to realize you don’t have it.'”

The lawyers for officers Edward Nero and Caesar Goodson, both found not guilty by Baltimore Circuit Court Judge Barry G. Williams, have laid out a road map for how to defend the four remaining officers, one of whom already received a mistrial after a jury could not reach a verdict. And one key element is provided by Maryland law: try your case before a judge, rather than a jury. Maryland is one of 16 states that allow defendants to waive a jury trial without the consent of the prosecution, according to the National Center for State Courts. In federal court, in Virginia and 33 other states, prosecutors must agree to a defendant’s request to waive a jury trial. Prosecutors in those states likely would not agree to waive a jury in such a high-profile case. In Maryland, they had no choice.

Having a judge hear the case instead of a jury removes much of the emotion and extraneous detail from the consideration of guilt or innocence. Judges have experience with crimes, with criminals, with the tactics and tricks of prosecutors and defense attorneys. They are less likely to be swung by the emotional resonance of a case, or how it will play with their neighbors. Judges are accustomed to making unpopular decisions; civilian jurors are not.

For Goodson, the judge was Williams, who had already heard Nero’s case and acquitted him. Williams is a former federal civil rights prosecutor and Baltimore city assistant prosecutor, but he was tough on the prosecution here, and gave plenty of signals that he wasn’t going to roll over for them. Three times he said prosecutors failed to turn over evidence to the defense.  “Isn’t that your duty, counsel? To turn things over?” Williams asked shortly before opening statements. “What else is out there that you didn’t turn over?”

The prosecution witnesses did not go well, another sign that Mosby rushed to charge before fully assessing the case against the officers. A prosecution expert testifying about whether Goodson gave Gray a “rough ride” in the back of the police van that day concluded, “I can’t say.” Somebody, a witness, had to testify that criminal behavior was involved. This was a case of murder, which requires intent, which required showing that Goodson meant to toss an unsecured prisoner around in the back of his van. Street surveillance videos also did not make the case for a rough ride.

And though the prosecution had a Maryland medical examiner who was confident that Gray’s death was not an accident, the defense was able to counter with its own expert, former District chief medical examiner Jonathan Arden, now a favorite of the defense bar. He said he believed the fatal neck injury Gray suffered came after the last stop, after he had been checked on multiple times during his ride to the station. As a battle of experts goes, that could create doubt even in a juror, much less a judge. And Williams said in his ruling there were “equally plausible scenarios” about where during the ride to jail Gray suffered his fatal neck injury. He said he reviewed surveillance footage 15 times from where prosecutors believe Goodson ran a stop sign and took a wide turn, and was unable to draw the same conclusion as prosecutors, that it was a malicious fatal maneuver by Goodson.

Prosecutors won a small victory by forcing Officer William Porter to testify, even though he faces his own trial and has already been tried once — to a hung jury. But Porter gave them the bare minimum, saying only that it wasn’t his responsibility to ensure Gray’s safety, it was the driver’s.

Baltimore police vans have video cameras in the back to monitor their prisoners. But in another strike against the prosecution, the camera in Goodson’s van wasn’t working. Baltimore police have moved to upgrade and modernize their vans, but that won’t help the prosecutors in any future Gray-related prosecutions.

“This shows how difficult it is,” said Ric Simmons, a criminal law professor at Ohio State University, “to prove cases of police lethal use of force beyond a reasonable doubt.” Simmons said, “This also shows that the recent string of grand juries that refused to indict in police lethal use of force cases were perhaps not so irrational after all..The legal case against Goodson was not very strong and a judge, who will look only at the evidence and the law, was much more likely to acquit than a jury.”

In his ruling, Williams said that “no evidence was presented that the defendant knew or should have known of the acute distress Mr. Gray may have been in at that time.” Later he ruled, “the Court finds that there is insufficient evidence that the defendant gave or intended to give Mr. Gray a rough ride…there has been no credible evidence presented at this trial that the defendant intended for any crime to happen.”

Eldridge reminded that the judge “was a prosecutor in Baltimore City. He’s saying, ‘not only did you lie during discovery, but I had to ask five or six times to have it now, but you didn’t have a scintilla of the evidence you said you did.'” He said there was no evidence of a “rough ride,” and that prosecutors “still have no idea when the injury occurred.”

State’s attorney Mosby faces a difficult choice now. Dismissing charges against the remaining four officers could set off the civil unrest she presumably forestalled by charging them less than two weeks after Gray’s death. But proceeding with four more trials after losing two and getting a hung jury on a third would probably be seen as unfair by the police and legal community, and further poison the relationship between her prosecutors and the city police, who must work together on every other case in the city every day.

“I don’t think this office has the wisdom to make that decision,” Eldridge said. “What’s sad is I worked there. I worked with Mosby. This is her youthful inexperience shining through. They’ve lost 50 experienced state’s attorneys since she’s been there, and crime in Baltimore has skyrocketed.”

Six Baltimore police officers were charged after Freddie Gray's death and arrest. On July 27, prosecutors dropped the remaining charges against three of the police officers awaiting trial. Here's a look at each of the officers. (Claritza Jimenez,Erin Patrick O'Connor/The Washington Post)