Freddie Grey prosecutor
Baltimore's chief prosecutor Marilyn J. Mosby charges six police officers over the fatal injury of Freddie Gray.Reuters

Baltimore's chief prosecutor Marilyn J Mosby is facing criticism after formally charging six police officers over the homicide of Freddie Gray, the man whose death has sparked violent protests across the US.

The state's attorney for Baltimore City surprised many by filing charges including murder and manslaughter against the officers who arrested Gray, shortly after she received a medical examiner's report that ruled his death was a homicide, according to the New York Times.

Officials had said that it could take considerable time for Mosby's office to complete its own investigation into the events and to decide whether to prosecute.

However, Mosby shocked the US by announcing the charges against the six officers involved in Freddie Gray's arrest at a press conference on Friday.

According to the Washington Post, Mosby texted her mother before she made the announcement warning the "heads up, national media is focusing on me".

She ousted a white incumbent in the 2014 Democratic primary elections by promising to hold police accountable.

She reinforced this sentiment during the press conference when she said: "I assured the family that no one was above the law."

Death was a 'homicide'

Gray was arrested on the morning of 12 April after catching the eye of Lieutenant Brian Rice and running away. He was chased down and then arrested for carrying a knife.

Mosby declared that the arrest was illegal, explaining that a knife found in Gray's pocket, which he was charged with carrying, was in fact legal under Maryland law.

Reading the findings of the report, Mosby, said: "Mr Gray suffered a severe and critical neck injury as a result of being handcuffed, shackled by his feet and unrestrained inside of the Baltimore police department wagon."

The medical examiner's report suggested that the officers failed to offer medical assistance to Gray at various times, even when he was found unresponsive on the floor of their van after he had repeatedly appealed for help.

Despite complaining that he could not breathe and needed an asthma inhaler, Gray was ignored and loaded into the van.

Pleas for help ignored

After being handcuffed and shackled by the ankles, Gray was placed in the back of a police van. However, he was not secured into a seat using seatbelts, which is required by Baltimore police procedure.

The Baltimore Police Department has been accused of seriously injuring several prisoners through using this practice, which is nicknamed "rough rides".

According to the report read out by Mosby, the police failed to offer any medical assistance even when Gray was lying on the floor of the van in an "unresponsive" condition.

"Despite Mr Gray's seriously deteriorating medical condition, no medical assistance was rendered or summoned for Mr Gray at that time by any officer," said Mosby.

The van made four stops on the way to the police station including one to pick up another prisoner.

Mosby has already faced a backlash from the lawyers and police bodies and police unions in the city.

Michael Davey, an attorney for the Fraternal Order of Police in Baltimore, described the charges as an "egregious rush to judgment".

He expressed skepticism that the state's attorney's investigation could be completed in two weeks, when it involves six officers and charges that range from misconduct in office to second-degree murder, the Washington Post reported.

Union leader threatens political careers

Gene Ryan, a police union leader, called for Mosby to appoint a special prosecutor, citing in a letter "the many conflicts of interest presented by your office conducting an investigation in this case".

Mosby, the African-American daughter and granddaughter of police officers, has been the state's attorney for Baltimore for less than four months, Washington Post reported.

Ryan pointed to Mosby having a personal relationship with the attorney for Gray's family: William H. "Billy" Murphy Jr.

Murphy raised money for Mosby's campaign and was a member of her transition team, according to Ivan Bates, a former prosecutor and experienced Baltimore defence lawyer.

Maryland campaign finance records seen by the Washington Post show Murphy contributed $5,000 (£3,300) to her campaign, but they also show the police union donated $3,250 (£2,145) to Mosby.

Ryan's letter also focused on Mosby's husband, Nick, a member of the Baltimore City Council who represents the West Baltimore neighbourhood where Gray was arrested.

Nick Mosby's political future "will be directly impacted, for better or worse, by the outcome of your investigation", the letter said.

Claims of a conflict of interest were dismissed by former Baltimore mayor Kurt L. Schmoke, who served on Mosby's transition team.

"The call for her to step aside is misguided," said Schmoke, a former state's attorney and now president of the University of Baltimore. "There is no basis in fact to question her integrity or independence in this matter."