NEW YORK — With an unexpectedly speedy and sweeping announcement on Friday of charges against six police officers in the death of Freddie Gray, Baltimore’s chief prosecutor seemed to signal that the days when police misconduct drew a wrist slap are over.
But prosecutors must still secure convictions in Gray’s death, and analysts say that could be difficult.
Brutality cases against police officers are notoriously difficult to win, and much about the case, including the evidence against the officers and their defense, remains unknown.
The state’s attorney for Baltimore City, Marilyn J. Mosby, is expected to seek an indictment, the next step toward a trial.
Her chronology of Gray’s arrest on April 12 argued that he had been wrongly arrested, was placed inside a police van without being properly restrained by a seat belt and, after suffering a severe spinal injury during transport, was repeatedly ignored despite pleading for medical help.
The six Baltimore Police Department officers face charges ranging from second-degree murder to manslaughter, assault, false imprisonment, and misconduct in office.
Mosby’s inquiry — “comprehensive, thorough, and independent,” she said Friday — was completed in 18 days, less than a fourth of the time that Missouri prosecutors spent investigating the death of Michael Brown, which triggered riots and protests in Ferguson, Mo., last year.
That speed and confidence belie the difficulty that prosecutors may encounter in convincing a jury or juries that the six officers broke the law.
The bar for a manslaughter conviction is comparatively low; a jury must find that a defendant knew his actions could lead to a death, but recklessly disregarded that risk.
“The prosecution would simply have to demonstrate that the police were aware that someone might die because they didn’t properly transport him,” said Jens D. Ohlin, a criminal law professor at Cornell Law School. “They don’t have to show that they wanted him to die.”
Second-degree murder is more serious, implying that a defendant either wanted to cause a death or intentionally caused an injury that he knew could lead to death.
Only one officer — the driver of the van, Officer Caesar Goodson — was accused of murder. Some have speculated that prosecutors will say Gray was deliberately given a so-called rough ride that slammed him against the van’s metal walls.
In Gray’s case, a Police Department general order required officers to restrain prisoners with seat belts during transport to prevent injuries. But that order, in effect at least since 1997 and updated nine days before Gray’s death, appears to have been loosely followed by Baltimore officers.
While Mosby offered a detailed timeline of the events surrounding Gray’s death, she did not disclose any of the evidence supporting it. Nor did she say any of the officers personally caused the spinal injury that killed him.
But whatever case prosecutors make will have to overcome the inherent deference to police officers that most jurors take with them to the courtroom, experts said.
“It’s always difficult to get a guilty verdict against a police officer except in the worst and strongest cases,” said David A. Harris, a University of Pittsburgh professor who is a leading expert on racial profiling in law enforcement.
“A police officer comes into a courtroom not just presumed to be innocent, but presumed to be the good guy,” according to Harris.
Both the swiftness and the scope of the charges brought on Friday carry weight in a city where, critics say, poor, mostly black neighborhoods have boiled for years with resentment over police officers’ tactics.
“The larger message, if there is one,’’ Harris said, “is that ‘We’re moving on these things. We’re taking them seriously, and there’s no longer going to be any kind of slowing down and taking it to the point where people wonder, whatever happened to that?’ ”