BALTIMORE — A Baltimore police report on the death of a black man who suffered severe spinal injuries while in custody was handed over on Thursday to the city’s chief prosecutor, who must decide whether to bring charges against any of the six patrol officers involved in the man’s arrest.

The office of Marilyn Mosby, the 35-year-old state’s attorney, will include the internal police report as part of its own investigation into the death of Freddie Gray, who was injured sometime between his arrest on April 12 for carrying a switchblade knife and his arrival at a police station.

Gray’s death a week later from his injuries has become the latest flashpoint in a nationwide debate about police use of lethal force against African-Americans and other minority groups.

After setting off demonstrations and a night of rioting in Baltimore, protests spread to other major cities on Wednesday, a reprise of demonstrations last year after police killings of unarmed black men in Ferguson, Missouri; Staten Island, New York; and elsewhere.

Mosby, an African-American who took office in January, said her staff was regularly briefed by police investigators during the course of their probe, and at the same time, her office has been conducting its own independent probe.

“We are not relying solely on their findings but rather the facts that we have gathered and verified,” Mosby said in a statement. “We ask for the public to remain patient and peaceful and to trust the process of the justice system.”

While there are no immediate plans to make the findings of the police report public, media reports, based on unnamed sources, began to emerge on Thursday, that further complicated any ready explanations for Gray’s death.

A Washington Post report suggested he tried to hurt himself while riding in a police van, and a local television report said the medical examiner saw no evidence that he suffered the fatal injury during his arrest.

Mosby faces the biggest test of her short career in trying to determine what exactly happened to 25-year-old Gray and whether any of the officers should face criminal charges. The six are on suspension.

The daughter and granddaughter of police officers and the wife of a city councilman, Mosby vowed during her campaign to crack down on repeat offenders and promised to be more visible in the community than her predecessor.

In an election questionnaire she filled out for the Baltimore Sun, she decried “the long-standing history of distrust between citizens and law enforcement, and the widespread belief that the State’s Attorney’s Office cannot offer protection from retaliation.”

She has also emphasized the need for safe neighborhoods, offering the story of a cousin whom she said was killed on his doorstep over a pair of sneakers.

While there were no immediate plans to make the police report’s findings public, it was delivered a day earlier than expected, highlighting the urgency with which officials view the Gray case.

“I understand the frustration. I understand the sense of urgency,” Baltimore Police Commissioner Anthony Batts told a news conference. “That is why we have finished it a day ahead of time.”

Community activists said putting the report in the hands of prosecutors would make a difference in defusing tensions.

A spokeswoman for the Baltimore police union, the Fraternal Order of Police Lodge 3, said she doubted the union would comment on the report.

“It helps a lot,” said Reverend Keith Bailey, president of Fulton Heights Community Association, where Gray had done court-ordered community service. “I think this is what everyone wanted.”

Billy Murphy, a lawyer who represents the Gray family, also said he was pleased that the case reached a new stage.

“Sure, it’s a good thing,” Murphy said. “Only a fool would be confident that the police would investigate themselves.”

The U.S. Department of Justice, headed by another African-American woman, Loretta Lynch, was investigating Gray’s arrest and death for possible civil rights violations.

Baltimore Mayor Stephanie Rawlings-Blake vowed to get justice done. She noted that she, Mosby and Lynch were important figures in the case.

“If, with the nation watching, three black women at three different levels can’t get justice… for this community, you tell me where you’re going to get it in our country,” Rawlings-Blake told reporters.

Police offered a fresh wrinkle to Gray’s case on Thursday, saying officials learned of a fourth, previously undisclosed stop by the police van en route to the station house after viewing footage from a private camera. It was not immediately known what the footage revealed about Gray’s injury.

But media reports raised fresh questions about what happened to Gray.

A prisoner who rode in the van with Gray said he had heard sounds that suggested the man was banging his own head against the wall, according to a document written by a police investigator and obtained by the Washington Post. The other prisoner could not see Gray because they were separated by a metal divider.

And unidentified law enforcement sources told a local ABN TV affiliate there was no evidence found that officers caused Gray’s injuries during his arrest.

The medical examiner found that Gray, who was not wearing seat restraints, suffered the blow when he slammed into the back of the van, apparently breaking his neck, sources told WJLA. It was unclear what caused Gray to bang his head.

The wound in Gray’s head appeared to match a bolt jutting out from the van’s back door.