Cellphone video captures the arrest of 25-year-old Freddie Gray by Baltimore police on April 12, a week before he died from a spinal cord injury while in police custody (The Baltimore Sun)

City officials suspended six police officers Monday as they investigate the death of a 25-year-old man who suffered a severe spinal cord injury while in police custody.

Freddie Gray had been hospitalized since his April 12 arrest and, according to his attorney, was in a coma when he died Sunday. On Monday, the mayor and police commissioner publicly pleaded for calm and promised a full accounting — an effort to keep Baltimore from becoming the latest flash point in disintegrating relations between police and communities across the country.

“It has been difficult to overcome decades of mistrust,” Mayor Stephanie Rawlings-Blake (D) said at a news conference, adding that she was encouraged by peaceful protests thus far. “Our community is experiencing a great deal of trauma. . . . None of us get the answers we need or the Gray family deserves by resorting to violence.”

Rawlings-Blake and the police commissioner said the results of an investigation would be turned over to prosecutors by May 1 to determine whether criminal charges are warranted. Officials said it was not clear how Gray was injured or whether he was hurt during his arrest or when he was in the back of a police van used to transport suspects.

Officials also were unable to answer other key questions, such as whether Gray was given prompt medical attention and whether he had done anything illegal or suspicious to justify officers detaining him in Gilmor Homes, a cluster of red-brick public housing on Baltimore’s west side.

Undated family handout picture of Freddie Gray. (Baltimore Sun)

Also left unexplained is a video from a bystander showing two officers dragging what appears to be a limp suspect to a police van.

Gray’s attorney, William H. “Billy” Murphy Jr., called the police news conference “bizarre” and added, “We had high expectations because everyone was talking about candor, and we got opacity.” Murphy, the son of a judge and civil rights leader, said that police officials appeared “frightened by the national micro­scope” and that “they are scrambling for the truth.”

Officers said in a court document justifying the arrest that they were in a high-crime area on that Sunday morning and that Gray, who was 5-foot-8 and 145 pounds, ran when he saw them, prompting a pursuit. The officers said they then found a switchblade in his pocket and arrested him.

Authorities said preliminary autopsy results confirmed a spinal cord injury but did not show any broken arms or legs. Officials also said that none of the officers interviewed describe using force during or after the arrest. The medical examiner has not yet ruled on a cause of death.

“When he was placed inside that van, he was able to talk, he was upset,” said Deputy Police Commissioner Jerry Rodriguez. “And when Mr. Gray was taken out of the van, he could not talk, he could not breathe.”

Gray’s death thrust Baltimore into the national spotlight as the latest city facing protests over police conduct and allegations of excessive force. Since last year’s outrage over the fatal shooting by police of an unarmed teen in Ferguson, Mo., similar tensions have erupted in Cleveland, where an officer shot and killed a 12-year-old boy who was holding a toy gun; on Staten Island, where a street hawker died while being restrained by officers; and in North Charleston, S.C., where a video showed an officer shooting a fleeing, apparently unarmed man in the back, killing him.

On Monday evening, a crowd of Gray’s friends, family and neighbors gathered a block from the spot he was detained. They chanted, “Black lives matter!” before heading down Mount Street toward the Western District police station. When they arrived, uniformed officers stood stoically as the crowd chanted: “All night, all day! We gonna fight for Freddie Gray!”

“It ain’t about being mad,” Adrian Muldrow, vice president of the Baltimore City chapter of the NAACP, yelled to fire up the crowd. “It is about asking for justice.”

Children sipping juice boxes and munching on snowballs held signs. One girl had a hand-painted sign with hearts: “RIP Freddie. I love you.”

The mood turned tense as police Lt. Col. Melvin T. Russell, who also is a minister, stepped into the crowd to engage the community. “I don’t like what happened any more than you do!” he hollered over the yelling protesters.

“You stop talking! It’s our turn right now!” a woman screamed at Russell in tears. “What would happen if it was one of yours?” another woman yelled.

Police announced immediate changes in how they deal with arrestees who seek medical care and are examining how detainees are transported.

Baltimore’s police commissioner, Anthony W. Batts, who was hired in 2012 from California, has previously introduced other reform efforts and has weathered complaints of other police-custody deaths.

Several months ago, Batts invited the U.S. Justice Department to review his department after the Baltimore Sun revealed that the city had paid out $6 million to settle 102 lawsuits filed since 2011 in police-misconduct claims, many involving assaults by police during questionable arrests. That review is ongoing, and Justice Department officials held a public meeting last week to hear complaints from residents. Hundreds showed up to air grievances.

Until Monday, Baltimore police had made only a vague reference to why officers had initially targeted Gray. Rodriguez said Sunday that the officers believed he was or had recently been involved in a crime. In a brief court document justifying the arrest, officers wrote that Gray “fled unprovoked upon noticing police presence.” Only after officers chased Gray down did they report finding a switchblade in his front pants pocket, which prompted his arrest.

Murphy called it an illegal “take-down,” saying: “There is no such thing as felony running. That’s all they got. He looked at me and he started running. . . . Everything that happens after that is illegal.”

Rawlings-Blake told reporters that she, too, lacks answers to this question. “I want to know why the officers pursued Mr. Gray,” the mayor said.

Rodriguez said Gray was caught about two blocks from where he had been spotted and “gave up without the use of force.”

At the news conference, police said little about a bystander’s video showing what appears to be officers dragging Gray to the police van while he yells about his leg. Officer Garrett E. Miller wrote in the court document that Gray was “arrested without force or incident.” Police released video from a surveillance camera — the only one they said captured at least part of the arrest — but it continually swivels and shows only fractions of the encounter.

Police said a police transport wagon was requested at 8:42 a.m. and that Gray asked for a respiratory inhaler. It not yet clear whether he received medical attention at that point. Four minutes later, the officer driving the van reported that Gray was “acting irate” and called other officers to help. Rodriguez said Gray was put in leg irons and put back in the wagon. It was unclear whether he was secured with a seat belt, as is required.

The officer picked up a second arrestee who was put on the other side of a metal partition; he could hear Gray but not see him. Rodriguez said that the driver then went to the Western District, and paramedics were called at 9:24 a.m. Rodriguez said investigators have interviewed that arrestee, as well as all the officers involved, but did not divulge details from their statements.

Mark Berman, Lindsey Bever and Abby Ohlheiser contributed to this report.