The Justice Department said Tuesday it has opened an investigation into the death of a Freddie Gray, a black man who died of spinal injuries he suffered during an arrest that involved being transported in a police van.

Gray, 25, was taken into custody April 12 after police “made eye contact” with him and another man in an area known for drug activity and the two started running, Baltimore police said. Gray was handcuffed and put in a transport van. At some point during his roughly 30-minute ride, the van was stopped and Gray’s legs were shackled when an officer felt he was becoming “irate” in the back of the van, police said.

He was rushed by ambulance to a hospital. Gray died Sunday – a week after his arrest – of what Deputy Police Commissioner Jerry Rodriguez described as “a significant spinal injury.”

Exactly how he was injured and what happened in the van is still not known.

Justice Department spokeswoman Dena Iverson said federal investigators will look for evidence whether an officer willfully violated a person’s civil rights by using unreasonable force.

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.

In the Baltimore case, six police officers have been suspended with pay while local authorities look into the death. The officers have been on the force anywhere from three years to 18 years.

According to court documents, Officer Garrett Miller accused Gray of carrying a switchblade, which was discovered in Gray’s pocket after he was stopped.

The lawyer for Gray’s family said he believes the 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.”

The suspended officers were identified as:

– Lt. Brian Rice, 41, with the department since 1997.

– Sgt. Alicia White, 30, with the department since 2010.

– Officer Caesar Goodson, 45, who has been there since 1999.

– Officers William Porter and Edward Nero, who along with Miller, all joined in 2012.

Kim Deachilla, a spokeswoman for the Baltimore Fraternal Order of Police Lodge 3, said a law firm that contracts with the union is representing them.

The officers’ specific roles in the arrest were not released by city officials. Bystander video shows officers on bicycles, in patrol cars and outside the transport van.

Police Commissioner Anthony Batts said the reason for Gray’s stop is “a question we have to dig into.”

Gray’s death has prompted daily protests and a vigil was planned Tuesday evening at the spot where he was arrested.

Harold Perry, 73, a retired small 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 the bystander video, Gray is screaming, but it’s not clear what he is saying. Police have also confirmed he asked for an inhaler and medical attention.

Capt. Eric Kowalczyk, a department spokesman, said Batts met with all six officers involved in Gray’s arrest on Monday. The Baltimore Sun first reported the meeting.

At a news conference Monday, officials vowed transparency and pledged to hold those found responsible accountable. Batts said the investigation will be completed by May 1 and the results will be sent to the state attorney’s office to determine whether criminal charges will be filed. Batts also said he is ordering that police review and rewrite “effective immediately” its policies on moving prisoners and providing them with medical attention.

(AP)