BALTIMORE - Baltimore police released videos Monday showing the arrest of a man who died of a severe spinal injury suffered in police custody. Six officers have been suspended, but investigators say they still don't know how it happened

A week after the arrest of Freddie Gray, police said still don't have any videos or other evidence explaining what happened to cause the "medical emergency" that an arresting officer said Gray suffered while being taken to the local police station, Deputy Commissioner Jerry Rodriguez said.

Autopsy results returned Monday show that Gray "did suffer a significant spinal injury that led to his death," Rodriguez said. "What we don't know is how he suffered that injury."

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Police also released a more detailed timeline of how Gray was arrested and transported on April 12.

A still from a cell phone video showing the arrest of Freddie Gray. CBS Baltimore

It revealed for the first time that Gray was placed in leg irons after an officer felt he was becoming "irate," that the van made several stops on its way to the police station, even stopping to pick up another prisoner in an unrelated case, after Gray had asked for medical attention several times.

Something must have happened between the time Gray was videotaped by a bystander being dragged into the van, and the time he arrived at the station in deep distress, the deputy commissioner said.

The handwritten report by the arresting officer says Gray "was arrested without force or incident," CBS News correspondent Chip Reid reported.

"When Mr. Gray was put in that van, he could talk, he was upset. And he was taken out of that van, he could not talk and he could not breathe," Rodriguez said.

Mayor Stephanie Rawlings-Blake vowed to provide the community with all the answers.

Police Commissioner Police Commissioner Anthony Batts said he is ordering that police review and rewrite "effective immediately" its policies on moving prisoners and providing them with medical attention.

"We are a community on edge right now. We hear, I hear, the outrage. I hear the concern and I hear the fear," Batts said, asking for calm. "We are on edge as a city, and I need your help to make sure we get this out in the proper way."

All six officers involved have been suspended, said Rodriguez, who is in charge of the department's professional standards and accountability.

Officer Garrett Miller's official request for a criminal charge against Gray, a 25-year-old black man who was only 5-foot-8 inches tall and 145 pounds, said that he had been arrested "without force or incident."

Miller sought a charge of carrying a switchblade, punishable by a year in prison and a $500 fine, according to court records obtained Monday by The Associated Press.

Miller's charging document doesn't provide any explanations for the injuries that would lead to Gray's death a week later. He wrote only that while being taken to the station, on April 12, "the defendant suffered a medical emergency and was immediately transported to Shock Trauma via medic."

Another 30 minutes passed before police finally called an ambulance to pick Gray up at the station. He arrived at the hospital in critical condition and died on Sunday after a weeklong coma.

The documents, which misspell Gray's name as "Grey," were first reported Monday by The Baltimore Sun. Police had not previously mentioned a knife, or publicly disclosed the charge against Gray.

Miller's signed report says he personally recovered the knife from Gray's pocket. It names five other officers to be summoned as witnesses in court, and says Gray was stopped after a brief foot chase because he "fled unprovoked upon noticing police presence."

The Gray family's attorney, Billy Murphy, disputed the police timeline and said the injuries Gray suffered while in police custody were fatal. "His spine was 80 percent severed at his neck," Murphy said.

"We have no confidence that the city or the police department is going to fairly and objectively investigate this case," Murphy added.

CBS News reported earlier that Gray's lawyers accuse police of covering up what happened. They say police have video of the arrest itself, and accused the department of withholding it to hide the facts.

Demonstrators protest the death of Freddie Gray outside Baltimore City Hall on Monday, April 20, 2015. AP Photo/David Dishneau

Activists protesting excessive use of force and even Baltimore city officials say they have more questions than answers. About 50 people marched from City Hall to police headquarters Monday, carrying signs reading "Black lives matter" and "Jobs, not police killings." They unfurled a yellow banner reading "Stop police terror."

"This is just one of the most egregious cases I've ever seen," said Colleen Davidson of the Baltimore People's Power Assembly, which she said organized the rally at the request of Gray's family. "We felt the need to be out here and make it known that we will not stand and watch things like this happen."

Rodriguez said his investigators will hand everything they find over to the office of State's Attorney Marilyn Mosby by May 1. She too appealed Monday for anyone with information to contact her office.

"I can assure the public that my office has dedicated all its existing resources to independently investigate this matter to determine whether criminal charges will be brought," Mosby said.