Officer William G. Porter will not be retried until June for his alleged role in the death of Freddie Gray, likely creating a problem for prosecutors who had hoped to call him as a witness at the coming trial of another officer charged in the case.
With charges still hanging over his head after a mistrial last week, legal experts say, Porter would be expected to assert his Fifth Amendment right against self-incrimination if called as a witness against Officer Caesar R. Goodson Jr., who will be tried next month.
Experts say that if prosecutors want Porter to testify or want even to introduce his statements to police investigators, they likely will have to grant him immunity.
"If they want to use those [statements], they have to find a legal way to force Officer Porter to take the stand or negotiate with him so he is willing to voluntarily waive his privilege against self-incrimination," said Adam Ruther, a defense attorney and former prosecutor.
Ruther said it is not impossible for prosecutors to get Porter on the stand, but they will have to find a "novel and cutting edge application of the Fifth Amendment" in lieu of dropping his charges.
Prosecutors and defense attorneys involved in the case are barred from discussing the trials because of a gag order imposed by Judge Barry G. Williams.
Porter's first trial on charges of involuntary manslaughter, second-degree assault, reckless endangerment and misconduct in office ended last week with a hung jury on all four counts, leading Williams to declare a mistrial.
The court announced Monday that Porter's new trial date is June 13.
Goodson, whose trial is scheduled for Jan. 6, faces the most serious charge — second-degree murder — of the six officers charged in Gray's arrest and death. He was the driver of the van in which Gray, 25, sustained a severe neck injury following his arrest April 12.
Gray died a week later, and all six police officers involved in his arrest and transport were criminally charged. All have pleaded not guilty.
The state has said in court that it considers Porter a "material witness" in its cases against Goodson and Sgt. Alicia D. White, who faces the same charges as Porter. Prosecutors had argued that they needed to try Porter first, before Goodson and White, so they could call Porter to the stand in those trials.
The court's announcement follows private scheduling meetings in Williams' chambers with prosecutors and defense attorneys. The new trial date will be formally entered at a hearing Tuesday morning.
Though Porter gave an extended statement to investigators in April, to use it in a trial, defense attorneys for Goodson must have an opportunity to cross-examine Porter on the witness stand, said David Jaros, a professor at the University of Baltimore.
"They need to get Porter up there" on the witness stand, Jaros said, because the Constitution ensures an absolute right to confront witnesses.
In his trial, Porter and his defense attorneys pointed to Goodson, as the van driver, responsible for Gray's custody and care after officers put Gray into a police van without a seat belt and with his hands and legs shackled.
Jaros said Porter's testimony was important for Goodson's trial because it provides a blow-by-blow framework of the events that transpired.
"It wasn't a situation where they needed Officer Porter to flip and testify against Officer Goodson; they need him to testify to his statement," Jaros said. "There are some holes in their timeline."
Prosecutors need Porter's testimony, experts say, even though Deputy Chief State's Attorney Michael Schatzow attacked Porter's credibility during closing arguments, saying Porter had "lied" to jurors. For example, Porter said Goodson called him for help checking on Gray but that they did not discuss Gray's condition. Schatzow said that stretched believability.
Beyond his coming trial, Porter has another reason for not taking the stand in any of the other cases: the possibility that federal prosecutors might file federal charges later.
Still, prosecutors could explore ways to grant him certain types of immunity that could nonetheless allow them to maintain a criminal case against Porter, Ruther said. They could issue a "use and derivative use" immunity letter, in which specific answers couldn't be used against him or form the basis of any new investigation.
"The state's attorney's office has some of their brightest lawyers on this case," Ruther said. "If there's a credible legal argument, I'm sure they will find it."
Jaros said the state will have to begin taking a hard look at giving Porter immunity following the nearly three-week trial that ended with jurors deadlocked.
"In some sense, they may have some political cover to give Officer Porter immunity," Jaros said. "They have a strong claim that they're doing as much as they can with what they have."
Baltimore Sun reporter Kevin Rector contributed to this article