BALTIMORE (AP) — A judge dropped an assault charge Monday against a Baltimore police officer charged in the death of a black man injured in a police transport van.

Baltimore Circuit Court Judge Barry Williams dismissed the second-degree assault charge against Lt. Brian Rice, the fourth of six officers — three black, three white — to be tried in the 2015 death of Freddie Gray. After three trials, Williams has yet to rule that any of the officers committed crimes. Rice is the third officer to let Williams alone decide their fate.

The judge said the prosecution’s basis for the assault charge was that Rice used the van in the alleged assault. Williams ruled that because Rice didn’t drive the van, prosecutors had no evidence.

Rice still faces charges of manslaughter, reckless endangerment and misconduct. One misconduct charge was dropped when the trial began last week.

Williams dropped the assault charge after the prosecution rested its case and Rice’s lawyers asked for the judge to acquit him.

Earlier Monday, two other officers charged in Gray’s death testified at Rice’s bench trial.

The trial resumed with testimony from Officer Edward Nero, who was acquitted, and William Porter, whose trial ended in a mistrial.

After prosecutors asked Nero about his defamation lawsuit against prosecutors and a joint defense agreement he entered with other defendants, Williams ruled that Nero was hostile to the prosecution, allowing them to ask him leading questions.

Gray died a week after suffering a spinal injury in the van, touching off protests and rioting.

About a dozen protesters, the largest group since the trial began, stood outside the courthouse, some holding signs referencing the recent police killings of black men in Louisiana and Minnesota.

Rice, the highest-ranking of the officers charged, is white. The judge, chief prosecutor and Baltimore’s mayor are African-American. Race has not been cited as a direct factor in Gray’s death, but his arrest and fatal injury added momentum to the Black Lives Matter movement, which decries the treatment of black Americans by people in power.