The U.S. Justice Department says it is investigating the death of an African-American man who suffered spinal injuries while in police custody in the eastern U.S. city of Baltimore, Maryland.
The federal investigation will look for civil rights violations in the case of Freddie Gray, 25, who was arrested April 12.
On Tuesday, hundreds of protesters gathered at the site of Gray's arrest. Protesters marched to a police station a couple of blocks away, chanting and holding signs that read "Black Lives Matter'' and "No Justice, No Peace" — slogans that have come to embody what demonstrators believe is mistreatment of blacks by police across the United States.
Among the crowd were members of Gray's family, including his mother, Gloria Darden, who was overcome with grief, writhing and sobbing uncontrollably, her face obscured by a hood and dark glasses.
Earlier in the day, six Baltimore police officers were suspended with pay while authorities investigate why Gray was stopped and what led to his injury. They were identified as Lt. Brian Rice, 41; Officer Caesar Goodson, 45; Sgt. Alicia White, 30; Officer William Porter, 25; Officer Garrett Miller, 26; and Officer Edward Nero, 29. Their specific roles in the arrest weren't disclosed.
Details about what happened to Gray are scarce. Baltimore authorities said he “was arrested without force or incident” after police "made eye contact'' with him and another man in an area known for drug activity and the two started running.
According to court documents, one of the arresting officers accused Gray of carrying a switchblade, which was discovered in Gray's pocket after he was stopped.
Harold Perry, 73, a retired businessman who is nearly blind, said he heard the arrest through his bedroom window. A young man was screaming, "You're hurting me! Get your knee off my back!" Perry said.
He said he also heard the young man say, "I'm an asthmatic."
In video of the event taken by a bystander, Gray is screaming, but it's not clear what he is saying.
Gray was handcuffed and put into a transport van. What remains unclear is what happened in the van that led the police to rush him to the hospital in critical condition about 30 minutes later.
At some point during the ride, the van was stopped and Gray's legs were shackled when an officer felt he was becoming "irate," police said.
Police Commissioner Anthony Batts said Gray asked for an inhaler, and then several times asked for medical care.
Gray died Sunday of what police described as a "significant spinal injury."
The lawyer for Gray's family said he thought police had no reason to stop him.
"They've made concessions on lack of probable cause," attorney Billy Murphy said. "Running while black is not probable cause. Felony running doesn't exist, and you can't arrest someone for looking you in the eye."
Batts said the reason for Gray's stop was "a question we have to dig into."
At a news conference Monday, Baltimore officials vowed transparency and pledged to hold those found responsible accountable. Batts said that the investigation would be completed by May 1 and that the results woiuld be sent to the state attorney's office to determine whether criminal charges will be filed.
Batts also said he was ordering that police review and rewrite "effective immediately" policies on moving prisoners and providing them with medical attention.
Baltimore Mayor Stephanie Rawlings-Blake said she welcomed the Justice Department probe. "Whenever a police force conducts an internal investigation, there are always appropriate questions of transparency and impartiality,'' she said. "My goal has always been to get answers to the questions so many of us are still asking with regards to Mr. Gray's death.''
It's not uncommon for federal investigators to look into allegations of excessive police force. Justice Department investigations in the last year include probes into the fatal shooting of an unarmed black 18-year-old in Ferguson, Missouri — a case that resulted in no charges against the officer — and an ongoing review of a police chokehold death of a New York City man.
There's a high threshold for bringing federal civil rights charges against police officers in such cases. Federal investigators must show an officer willfully deprived a person of his or her civil rights by using more force than the law allows, a standard that's challenging in rapidly unfolding confrontations in which snap judgments are made.
Some information for this report came from AP.