Brandon Ross, Freddie Gray and another friend were walking through their West Baltimore neighborhood to a carpentry job the morning of April 12, Ross testified.

“We were turning a corner, and Freddie started running,” Ross recalled. “He started running fast.”

When Ross saw Gray a few minutes later, the 25-year-old was surrounded by police officers a couple blocks away. Then police “threw him into the back of the van” like he was “hogtied,” said Ross, one of several witnesses who testified Thursday in the first trial in Gray’s death.

Prosecutors played shaky cell video of that chaotic moment, and as it ended, a sob cut the silence in the courtroom. Gray’s mother, Gloria Darden, had broken down and was quickly escorted out, wrapped in the arms of another woman. Ross, who had known Gray for a decade, pulled on a baseball cap and also left the darkened courtroom in tears.

The scene was part of an emotional second day of testimony in the trial of Officer William G. Porter, one of six officers charged in Gray’s arrest and death. Ross’s testimony came a day after prosecutors and defense attorneys laid out two starkly different arguments about Porter’s treatment of Gray during his ride to central booking.

Freddie Gray (Baltimore Sun)

In addition to watching the viral video of Gray’s arrest that captured the public’s outrage and touched off days of rioting in the city, jurors on Thursday also left the courtroom to view the Baltimore Police wagon in which Gray sustained a severe neck injury that ended in his death one week later.

Prosecutors Michael Schatzow and Janice Bledsoe opened the morning proceedings by calling witnesses to underscore their allegations that Porter, who faces charges including involuntary manslaughter, neglected his duties as an officer. Prosecutors said that at multiple times, Porter failed to properly buckle Gray into the police van and get Gray medical attention after the young man asked for a medic and said, “I can’t breathe.”

Prosecutors have argued that Gray was likely injured when he fell in the back of the van. They say that Gray could not break his fall because his arms and legs were restrained, though exactly how Gray was injured remains unclear.

Officer John Bilheimer, who was an instructor at the Baltimore Police Academy, testified that he taught Porter procedures for using emergency vehicles and transporting arrestees in 2012. Bilheimer testified that Porter was taught to strap people into police vehicles and that the procedure was part of the general orders given to officers.

“The arrestee is secured with seat and restraint belts provided,” Bilheimer read from the department policy, also noting that the department manual directs officers to call medics for people who are injured.

He also read notes from Porter’s old study guide, which shows the officer penned the following: “We do not transport injured people.”

Here’s what you need to know as the trial of William G. Porter, one of six police officers charged in the case of Freddie Gray’s death, starts in Baltimore. (Ashleigh Joplin/The Washington Post)

But he also bolstered the defense on cross-examination, agreeing that the order about the seat belt is for internal use only and does not apply to civil or criminal liability. He also acknowledged that primary responsibility for securing a detainee rests with the person driving a police van.

Porter’s attorneys have argued that Gray initially showed no obvious signs of severe injury and that Porter did what any other officer would have done, saying that the department’s officers rarely put detainees in seat belts.

Porter’s attorneys, Gary Proctor and Joseph Murtha, emphasized Thursday that their client did not know about new protocols related to how officers should secure detainees and ensure their safety. They also emphasized that officers have to use their judgment on a case-by-case basis.

Capt. Martin Bartness told jurors that he wrote the directive requiring Baltimore officers to obtain medical care for detainees when “necessary or requested.” The policy went into effect nine days before Gray’s arrest and was e-mailed to officers, including Porter, three days before that. The e-mail was one of more than 1,400 pages of messages Porter received that day, and the policy was included in 80 pages of attachments outlining several new rules that took effect that month.

Witnesses could not say whether the department checked to see whether Porter opened the e-mail and read it.

In what is a central point in Porter’s defense, his attorney suggested to Bartness that proper protocol is simply not that important to Baltimore officers.

“They’re more interested in catching bad guys,” Proctor said.

Bartness disagreed, saying that both compliance and crime fighting are important. He also emphasized that new protocols weren’t just e-mailed to officers: Commanders were also responsible for making sure that subordinates knew about them.

Both responses cut against the defense’s argument that officers often were not aware of new rules.

Just before lunch, jurors went to the parking garage of the courthouse to view the van in which Gray’s spine was nearly severed. The judge denied a media request to accompany the jury while it viewed the vehicle but said that no questions were asked of or by the jury during the viewing and that no information was presented to them.

On the outside, at least, Porter appeared relaxed in court. He has waved and smiled at well-wishers, some of whom approached him for handshakes and hugs.

Thursday’s most compelling testimony came from Ross, who said he and Gray were “like brothers.”

Ross, 31, walked the jury through various videos capturing Gray’s arrest. The footage was often punctuated by screams from Gray or bystanders watching the scene unfold. Later in the day, Ross got on his knees in court to simulate how he saw Gray being handled by police.

Porter, Ross acknowledged, did not arrive at the scene until Gray was already on his knees. Ross said he flagged down Porter, whom he knew by name because the officer regularly patrolled that neighborhood. He said he told the officer he filmed Gray’s encounter with police and asked to talk to a supervisor. According to the defense, Porter pointed one out.

Porter has pleaded not guilty to involuntary manslaughter, second-degree assault, reckless endangerment and misconduct in office.

Ross, who was emotional during much of his testimony, was reluctant to answer the defense’s questions. When asked by Proctor if he would believe that a security camera image showed him speaking peacefully to Porter, Ross replied, “I can’t believe what you say.”

“I get that a lot,” Proctor jokingly responded. He then asked if Porter was the person Ross trusted to lodge his complaint about how police treated his friend.

Ross quickly responded.

“I wouldn’t use the word ‘trust.’ ”

John Woodrow Cox contributed to this report.

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