The disclosure from Porter's attorneys came as they argued that he should be able to present character witnesses to demonstrate his "reputation for peace and good order." Defense attorneys wrote in a pretrial motion that Porter "anticipates testifying in this matter," and prosecutors say he plans to call up to 25 character witnesses, which they labeled "absurd."
That motion, posted online by the court Wednesday, was among a flurry of filings by the defense and prosecution as Porter's Nov. 30 trial date nears.
In a separate filing, prosecutors sought to prevent the defense from mentioning Gray's past encounters with law enforcement, saying they are irrelevant to the allegations against Porter. Among the other motions: Prosecutors requested permission to let jurors inspect the interior of the police transport van in which Gray was fatally injured, and the defense asked to exclude videos that area residents shot of Gray's arrest.
Judge Barry Williams could rule on the motions ahead of trial, or hear arguments and make his rulings once the trial has begun. Because of a gag order imposed by Williams, attorneys on both sides are barred from discussing the case, including the latest motions, filed Nov. 12.
Gray died in April of injuries sustained in a police transport van, prosecutors allege. Six officers face charges ranging from misconduct to murder; all have pleaded not guilty.
Porter is charged with manslaughter and misconduct in office, and his case is considered a bellwether for the remaining officers' cases because the outcome could force prosecutors and defense attorneys to reconsider their strategies, legal experts have said. Porter's case could even determine whether the trials remain in Baltimore, with Williams saying he wants to see if a fair and impartial jury can be selected.
Prosecutors have previously said that Porter is a "necessary and material witness in the case against" Officer Caesar R. Goodson Jr. and Sgt. Alicia D. White, prompting Porter's trial to be held first.
David Jaros, a University of Baltimore law professor who has been following the cases, said a defendant's decision about whether to testify is one of the most important he'll make with defense lawyers. The filing does not guarantee that Porter will testify, but it leaves the option open, Jaros said.
If a defendant doesn't testify, jurors are instructed not to hold it against him, Jaros said. But that can be difficult for jurors to do, he added.
Similarly, if a defendant can fill in gaps in the chronology or add a more sympathetic perspective, that testimony can be powerful.
Jurors "want to hear from Officer Porter about 'What did you see, what were you thinking?'" Jaros said.
In their request to present character witnesses, Porter's attorneys say that by taking the stand, he may be attacked by prosecutors. He wants to be able to call witnesses to vouch for him.
Prosecutors responded that his "purported character … would be plainly irrelevant." They said the allegations that he contributed to Gray's death are based on "acts of criminal negligence, not intentional infliction of injury."
"Testimony that the defendant's witnesses believe he has a character or reputation for truthfulness would not be relevant to any of the crimes charged because none of them involve dishonest conduct," prosecutors said.
Character witnesses can be used to bolster Porter's reputation for honesty, Jaros said, but they are limited to testifying in generalities rather than bringing up specific examples of his good deeds. "I don't think we're going to find this ends up being a game-changing aspect of the case," Jaros said.
The Baltimore Sun previously reported that Porter told police investigators that after being summoned to check on Gray on the morning of April 12, he told the driver of the transport van that the city booking facility would not process Gray because he was in medical distress.
Porter helped Gray up and asked, "Do you need a medic or something? Do you need to go to the hospital?" according to a police account of the statement Porter provided in an initial police review of the incident.
Gray responded affirmatively, Porter told investigators. But Porter added that he wasn't sure whether Gray was in distress or was trying to persuade officers to take him to the hospital instead of jail.
In their request to limit information about Gray, prosecutors say they believe Porter's attorneys will try to bring up Gray's criminal record, previous hospitalizations or civil claims, and his exposure to lead paint as a child. Gray, 25, was arrested more than a dozen times as an adult, mostly for drug-related offenses, and had been convicted five times.
Prosecutors said "the issues that the jury will consider bear zero relation" to Gray's past and would not "demonstrate a lesser probability" that Porter's alleged actions caused or risked Gray's injury or death.
Similarly, prosecutors sought to bar defense attorneys from "trying the prosecutor" by raising questions about their conduct surrounding the investigation. Prosecutors say such a ploy could distract the jury.
Defense attorneys in the case previously tried and failed to remove the state's attorney's office from the case or impose sanctions for what was described as unethical conduct.
Baltimore Sun reporter Ian Duncan contributed to this report.
The officers charged in Freddie Gray's arrest and death will be tried separately; all have pleaded not guilty. Here are the scheduled trial dates:
•Officer William G. Porter: Nov. 30
•Officer Caesar R. Goodson Jr.: Jan. 6
•Sgt. Alicia D. White: Jan. 25
•Officer Garrett E. Miller: Feb. 9
•Officer Edward M. Nero: Feb. 22
•Lt. Brian W. Rice: March 9