Chief Deputy State's Attorney Michael Schatzow zeroed in on differences between Porter's testimony in his manslaughter trial and a statement the young Baltimore police officer gave to internal investigators just days after Gray suffered a fatal neck injury in the back of a police transport van in April.
"You did not protect Freddie Gray's life, did you?" Schatzow said.
"Untrue," Porter said.
Porter's testimony came on the first day of his defense team's presentation, which also included testimony from a well-known forensic expert who contradicted the findings of the state medical examiner's autopsy, and another police officer who took part in Gray's arrest and was granted immunity by the state.
Porter calmly responded to questions from his attorney, Gary Proctor, but bristled at times under cross-examination by Schatzow.
He said that taking the stand allowed him to elaborate on what he said in his April statement. When he gave his initial statement, he said, he thought he was just a witness — not a suspect.
"I didn't know I needed to defend myself," he said.
Porter, 26, has pleaded not guilty to charges of manslaughter, second-degree assault, misconduct in office and reckless endangerment in connection with Gray's death. Prosecutors allege he "criminally neglected his duty" by failing to secure Gray with a seat belt in a police transport van on April 12 and not calling for medical assistance when Gray requested it.
Gray, 25, died of his injuries a week later. His death was followed by widespread protests against police brutality, especially in predominantly African-American communities, and his funeral was followed by rioting. Like Gray, Porter is black.
Baltimore State's Attorney Marilyn J. Mosby charged Porter and five other officers involved in Gray's arrest and death several days after the funeral and riots. All have pleaded not guilty.
Porter's testimony Wednesday was marked by contentious exchanges with Schatzow and by dramatic demonstrations in which Porter's other attorney, Joseph Murtha, got on the ground and pretended to be Gray as Porter described Gray's position in the back of the van.
In a key exchange, Porter disputed the prosecution's claim that he told a police investigator in April that Gray told him he couldn't breathe at the fourth stop of the van.
Porter testified that he overheard someone — who he later learned was Gray — mentioning having trouble breathing, but that was at the first stop, when Gray asked for an inhaler. Porter said if Gray had told him he couldn't breathe at the fourth stop, he would have immediately called for a medic.
At another point, Schatzow stood a few feet in front of Porter and asked him why he could not recall the identity of the officer who placed Gray into the van at its second stop, despite being about the same distance from the van as Schatzow was from the witness stand. A video showing Porter's proximity to the van during that incident had just played.
Schatzow then asked Porter about the "stop snitching" culture in Baltimore, in which witnesses to crimes rarely speak up. "Is that culture in the Baltimore Police Department?" Schatzow asked.
"Absolutely not," Porter said. "I'm actually offended that you would say something like that."
In the coming days, the defense is expected to call character witnesses on Porter's behalf. On Wednesday, Proctor also prompted Porter to describe his life, his demeanor as a police officer and what he knew of Gray before that day.
Porter testified about growing up in West Baltimore and becoming familiar with law enforcement at an early age at police athletic camps for children, which he attended in part because they were free. His mother, a nurse, didn't have money to pay for other activities, he said.
He joined the department in 2012, he said, because he sensed a growing distrust between the community and police, and he wanted to "give people a different perspective."
Porter said he was "always fair" as an officer, and that he had certain pet peeves — including littering. He said he would tell people who threw trash on the street, "You should be proud of where you come from. So you shouldn't litter."
He recalled telling residents about the proud and deep African-American history in the Sandtown-Winchester neighborhood where Gray was arrested.
Porter said he was familiar with Gray as a "regular fixture" in the neighborhood, and that he and Gray would talk whenever Gray wasn't "dirty," or carrying drugs. He'd never arrested Gray, Porter said, but witnessed a prior arrest in which Gray tried to kick out the window of a police vehicle.
Before Porter, the defense called a medical expert who rebutted assessments from state medical examiner Dr. Carol Allan, including that Gray's death was a homicide and that he was injured between the second and fourth stops of the van. Porter's first interaction with Gray was at the fourth stop.
Dr. Vincent Di Maio, a forensic pathologist and former chief medical examiner in San Antonio, said Gray's injury was "so violent, it's so high-energy" that it would have immediately caused Gray to lose control of his body and his diaphragm, which is critical for breathing and speaking.
"This has all the appearances of a single catastrophic injury," he said, and one that would have "cut off the head from the body" in a neurological sense almost immediately. Because of that, he said, Gray could not have suffered his injury before the fourth stop — where he spoke with Porter — and must have suffered it between the fifth stop and the last, where Gray was discovered unconscious.
Di Maio is an accomplished but controversial expert in forensic pathology. He was a chief medical examiner in Texas for more than 30 years and was involved in an exhumation of Lee Harvey Oswald, the accused assassin of President John F. Kennedy. More recently, he testified for the defense in the trial of George Zimmerman, who was later acquitted in the death of black teenager Trayvon Martin. He also authored a textbook on "excited delirium," a condition often cited in police custody deaths that has been questioned.
Schatzow, while cross-examining Di Maio, pointed out that Gray's spinal cord was not 100 percent cut, and questioned whether Di Maio was sure that an injured Gray would not have been able to speak at the fourth stop.
"Completely impossible?" Schatzow asked.
"Yes, sir," Di Maio said.
After Porter, the defense called another Baltimore police officer, Zachary Novak. Novak was involved in Gray's initial arrest and also called a medic to the Western District police station after Gray was discovered there unconscious.
But he is not one of the six officers charged in Gray's arrest and death. Instead, Novak was offered immunity in the case by prosecutors and served as a witness for the state before the grand jury that indicted the officers.
Novak testified that he places detainees in seat belts when he transports them in his vehicle, but when he observed suspects transported in a wagon, he said they were seat-belted only about 10 percent of the time. He also testified that van drivers are understood to have "primary custody" of detainees in their vehicles.
Earlier, Porter testified that he had participated in 150 arrests involving police transport vans, and none of the detainees were seat-belted.
On cross-examination, Deputy State's Attorney Janice Bledsoe suggested Novak had changed his answers to certain questions for the trial, compared to his grand jury testimony — including his description of Gray's exact position when he was found in the van at the Western District.
Novak testified that he could not recall Gray's exact position but said he believed Gray's head was close to the rear of the wagon because he would remember if he had to climb into the van to pull Gray out. Instead, he only recalls hooking his arms under Gray's to lift him out, he said.
Novak's testimony concluded the day. The trial will resume with more defense witnesses Thursday.
Proctor asked Porter if he was sorry Gray had died, and Porter said he was.
"Freddie Gray and I weren't friends, but we had mutual respect for one another," he said. Gray understood Porter had a job to do, the officer said, and he understood why Gray did what he did on the streets. "We built a rapport."
Porter said it "felt like an eternity" for the medic to arrive as he held Gray in a "life-saving position" after finding him unconscious.
"It was a very traumatic thing for me also," Porter said. "Just seeing him in the neighborhood every day, and calling his name, and not getting a response."