When Marilyn Mosby was elected in January as state's attorney for the city of Baltimore, it's unlikely she had any inkling that just four months later she would be thrust into the national spotlight.

But as Mosby stood behind a bank of microphones Friday and announced criminal charges - including murder and manslaughter — against six police officers in the death of Freddie Gray, it looked as though she was born into the job.

There were concerns that an investigation into the April 12 arrest of 25-year-old Gray, and his subsequent death one week later, would linger or would result in a white-wash. But in a gripping news conference, Mosby quashed those concerns.

She gave graphic details of how Gray was mistreated and neglected by police from the time he was arrested until he arrived at the police station unconscious and in cardiac arrest. As NPR reported, Mosby then read out the names and criminal charges against each of the six police officers.

At 35, Mosby is the youngest top prosecutor in any major city in the U.S. When she ran for office last autumn, she promised voters she would be tough on violent criminals and would tackle police misconduct, according to the Baltimore Sun.

"Police brutality is completely inexcusable. I'm going to apply justice fairly, even to those who wear a badge," she said.

Mosby, a mother of two daughters, comes from five generations of law enforcement officials, including her mother and father, aunts and uncles. Her grandfather was a founding member of the first association for black police officers in Massachusetts. During her news conference, she addressed Baltimore's police force.

"I can tell you that the actions of these officers will not and should not in any way damage the important working relationships between police and prosecutors as we continue to fight together to reduce crime in Baltimore," she said. "Thank you for your courage, commitment, and sacrifice for the betterment of our communities."

Mosby's interest in justice sprang from tragedy, according to The New York Times. When she was growing up in inner-city Boston, her 17-year-old cousin was mistaken for a drug dealer and killed outside her home by another teenager in broad daylight.

Mosby is married to Baltimore City Councilman Nick Mosby, who represents areas of Baltimore where riots erupted this week. There were calls from the city's police union to excuse herself from the case. Today she waved away those calls.

"I uphold the laws; he makes the laws," she said. "And I will prosecute any case within my jurisdiction."

But the police officers' union, the Baltimore chapter of the Fraternal Order of Police, said Mosby had conflicts of interest. She has been supported politically by William Murphy Jr., the lawyer for Gray's family. Gene Ryan, president of the local union chapter, defended the conduct of the six officers, according to the Baltimore Sun.

"As tragic as this situation is, none of the officers involved are responsible for the death of Mr. Gray," Ryan wrote in an open letter to the state's attorney.

But there was satisfaction with Mosby today among many Baltimore residents. NPR's Jennifer Ludden says many people were happy with the prosecutor's swift action, including Theresa Parker.

"Oh, I'm just happy that it's all over with," Parker said.

Even before the Freddie Gray case erupted, there were signs that she was having a positive impact on the city, as seen in this letter written by Patrick Lynch to the Baltimore Sun.

"She may be remembered many years from now as the state's attorney who brought real and lasting change in turning around the inexplicable bloodletting in our city," Lynch, of Nottingham, Md., wrote.

There was a cheer today when Mosby announced criminal charges. She indicated she understood the public's frustration and anger over Gray's death, and she appealed for calm.

"Your peace is sincerely needed as I work to deliver justice on behalf of this young man," she told the crowd.

Mosby's instant rise to fame may best be illustrated by the number of hits on . Shortly after her news conference, the site said: This application is temporarily over its serving quota. Please try again later.

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