A Baltimore city judge acquitted officer Edward M. Nero on May 23 of four criminal counts in the case of Freddie Gray. Nero is one of six police officers charged in Gray's arrest and subsequent death. (Ashleigh Joplin/The Washington Post)

A judge found police officer Edward M. Nero not guilty of all criminal charges in the case of Freddie Gray, whose death last year in police custody sparked riots and widespread anger in the city.

The acquittal by Judge Barry G. Williams, announced Monday in a packed courtroom, is the first verdict reached in the Gray case. Nero is the second officer to face trial on charges related to Gray’s arrest and death. The first officer’s trial ended in a hung jury.

Nero, 30, hugged his lawyers and wiped away tears after Williams read his decision, which culminated the six-day trial. Friends and fellow officers, including Officer Garret Miller, who is also charged in connection with Gray’s arrest, lined up afterward to congratulate Nero. The officer had opted for a bench trial rather than have his case heard before a jury.

Nero is among six Baltimore officers to face charges in the case of Gray, 25, who died in police custody a week after being injured in the back of a police van in April 2015. Gray’s death sparked rioting and arson fires in the city and brought additional scrutiny to the deaths of young black men at the hands of police officers nationwide.

Events leading to Freddie Gray’s death, explained in augmented reality

Nero was acquitted of second-degree assault, reckless endangerment and two counts of misconduct in office. All of the charges are misdemeanors; Nero was not charged in Gray’s death. Nero’s attorney, Marc Zayon, said in a statement that the “nightmare is finally over” for Nero, his wife and the rest of the family. He said Nero and the other officers charged had “done nothing wrong” and urged the prosecutors to drop the remaining cases.

Nero, one of the first officers to encounter Gray the day of his April 12, 2015, arrest, was on bike patrol when he responded to a call for a chase. He stood watch as Gray was arrested, according to testimony, but he did not touch Gray until the young man was already in custody. Nero later helped load Gray into the police van but did not secure him with a seat belt.

It was not immediately clear what, if any, effect Monday’s verdict could have on the cases against the other officers or if the remaining defendants would also choose to have their cases decided by a judge rather than a jury. The officers who still face trial, their lawyers and the prosecution are under gag orders and are not permitted to discuss their cases.

Immediately after the verdict was announced, a small group of protesters demonstrated outside the courthouse, but the scene remained mostly calm. At one point, a cluster of demonstrators chanting “No justice, no peace” briefly surrounded a member of Nero’s family as he walked to a parking lot.

Tessa Hill-Aston, head of the Baltimore NAACP, said she was disappointed with the outcome.

“It’s not a good day,” she told reporters. “Freddie was fine until they stopped him . . . and they had no reason to arrest him.” She said she expected an “emotional” reaction from many city residents, as she had been in court with people “from all walks of life” who were upset by the verdict.

Westley West, a 28-year-old minister in Gray’s West Baltimore neighborhood, said after the verdict that he was frustrated by what he sees as a lack of accountability in Gray’s death.

“That’s a problem for me,” West said. “We need justice in Baltimore.”

In a statement, Lt. Gene Ryan, president of the Baltimore Fraternal Order of Police, applauded the decision. “The state’s attorney’s office responded to the riots and violence in Baltimore by rushing to charge these officers rashly and without any meaningful investigation,” he said.

Billy Murphy, an attorney for the Gray family, said that “as long as this was a fair process, then justice was done.”

Baltimore Mayor Stephanie Rawlings-Blake said Nero will now face an administrative review through the police department. She said the city was prepared for the possibility of unrest. By afternoon though, there had been no reports in Baltimore of any disturbances in response to the verdict.

After Gray’s arrest last year, he was placed in the back of a police van with his hands cuffed behind his back and his legs shackled. Prosecutors say he suffered a neck injury and lost consciousness as he was being transported. He died about a week later.

The prosecution had argued that Gray never should have been arrested in the first place, saying he was detained without probable cause and his arrest amounted to second-degree assault. The state also argued that Nero was guilty of reckless endangerment for failing to seat-belt Gray in the police van. Just days before the arrest, an email was sent to all officers noting that department policy required that all detainees, without exception, be secured with seat belts during transport.

The defense contended that Nero, who responded to a call to chase a fleeing suspect in a high-crime area, acted as any reasonable Baltimore police officer would during the incident.

Zayon argued that Nero didn’t touch Gray when he was first detained, and later only touched him in an effort to help him find his inhaler. The defense also said there was no evidence that Nero read the department's new seat-belting order. Several officers who testified said that it was not common practice to have detainees wear seat belts.

In his lengthy ruling from the bench, Judge Williams addressed each charge in detail, restating the prosecution’s arguments for conviction and the defense’s rejoinders. In each instance, Williams ruled that the state had not established guilt beyond a reasonable doubt.

On the assault charge, Williams said that Nero was not the officer who made the stop and arrest, did not handcuff Gray and thus could not be convicted of assault or the misconduct charge associated with it. The judge said the initial contact between Nero and Gray “was legally justified and not reckless.”

Williams also found the state did not prove Nero committed a crime by failing to secure Gray with a seat belt. The judge said prosecutors did not show Nero had direct responsibility for placing a seat belt on Gray or even that he was trained to do so.

The new seat belt requirement “may not have gone into effect until after the incident in question,” the judge said. Either way, he said, the charge of misconduct required “corrupt” intent, and the state did not prove that.

“Mere error in judgment is not enough to constitute corruption,” he said.

The verdict is a blow for Baltimore City State’s Attorney Marilyn Mosby, who brought charges against the six officers May 1, 2015. Mosby sat in the front row for much of the trial but was not in court for the verdict. Prosecutors Michael Schatzow and Janice Bledsoe handled the case.

“This is a real shot across the prosecution’s bow,” said Tyler Mann, a Baltimore defense lawyer who previously served as a Baltimore prosecutor. “When you can’t even convince one person that he broke the law, that’s not a good sign.”

Mann said he doubts that the result will change the way prosecutors handle the other officers’ cases.

“I think they’re going to move forward with every case — they’ve made their bed, and now they have to lie in it,” he said.

In an earlier trial involving Officer William G. Porter, jurors were unable to reach a decision, and a mistrial was declared. Porter will face retrial later this year.

The officer facing the most serious charges, police van driver Caesar R. Goodson Jr., is set to go to trial June 6.

Rep. Elijah E. Cummings (D-Md.) said at a news conference Friday that the trial had exposed what appeared to be gaps in police training. “We really have to learn from this incident, the idea that maybe officers were not trained in something that they should have been trained in,” he said. “Hopefully we will learn.”

Baltimore police said outside police agencies are handling the inquiry into whether Nero, who joined the force in 2012, and the other officers involved in the Gray case followed department policy.

A city police spokesman said it will not be completed until the criminal cases against the five other officers are finished. That is because the officers could be called as witnesses at one another’s trials. Nero will remain on “administrative capacity” until then, the department said.

Keith L. Alexander, Lynh Bui, Peter Hermann and Dana Hedgpeth contributed to this report.