By DAVID HUNN

Tribune News Service

CLAYTON, Mo. -- The county's beleaguered prosecutor stood in front of cameras Monday evening and delivered the news:

Ferguson police Officer Darren Wilson will not be charged.

The announcement drove hundreds into the streets. From Ferguson to Shaw to Clayton, the region has braced for this night for more than three months.

The Aug. 9 shooting of unarmed 18-year-old Michael Brown turned the eyes of the world to Ferguson. Brown's death triggered months of protests, and focused national concerns about policing and race on a suburban St. Louis community that had considered itself a strong example of racial harmony.

And it split the region into Wilson supporters and Brown supporters.

Some hope St. Louis will never be the same. Others fear it won't.

On Monday night, St. Louis County Prosecuting Attorney Robert P. McCulloch announced Wilson will not face state criminal charges in the killing of Brown in Ferguson.

McCulloch said the 12-member grand jury considered a range of charges from murder in the first degree to involuntary manslaughter before deciding not to indict.

But McCulloch also said the protests spawned by the shooting have started an important conversation.

"It's opened old wounds and given us an opportunity to address those wounds," he said.

"I urge everybody who's engaged in the conversation, who's engaged in the demonstrations, to keep that going and not let that go," McCulloch said.

A separate federal investigation into whether Wilson violated Brown's civil rights is continuing, officials said. McCulloch said the two investigations had worked in harmony and evidence was shared among investigators.

Officials, Brown's family and some protest leaders pleaded for a peaceful reaction to news that seemed certain to anger those who called for Wilson's arrest and immediate prosecution for murder.

The family of Brown said in a statement they were "profoundly disappointed that the killer of our child will not face the consequence of his actions."

They urged protesters to avoid violence.

"While we understand that many others share our pain, we ask that you channel your frustration in ways that will make a positive change," they said in the statement. "We need to work together to fix the system that allowed this to happen. Join with us in our campaign to ensure that every police officer working the streets in this country wears a body camera."

McCulloch's announcement drew response from area politicians, some who said they were upset by the ruling, and all who called for work to continue.

Gov. Jay Nixon issued a statement calling on Missouri to "use the lessons we have learned these past four months to create safer, stronger and more united communities."

"The world is watching," Nixon said in the statement. "I am confident that together we will demonstrate the true strength and character of this region, and seize this opportunity to build a more just and prosperous future for all."

St. Louis County Executive Charlie Dooley called on the St. Louis region to "begin the hard work of healing."

"The grand jury has done its work, and now we must do ours," Dooley saidt. "This will be a long road but it is one we must surely travel."

Dooley also urged the public to refrain from violence. "Keeping people safe should be everyone's top priority. I understand that people are certainly emotional, but please think before you act."

Communities of color have seen for many years two types of policing, said Jeffrey Mittman, executive director of the American Civil Liberties Union of Missouri. One has been for wealthy, privileged citizens, and another for communities of color and poverty.

"The Michael Brown situation has raised to the consciousness of all communities these different types of policing," Mittman said.

"We, as a country, are aware that something matters here."

It's been a tense, brooding three months in St. Louis.

Wilson shot Brown on Aug. 9. Brown's body fell, face down, in the middle of Canfield Drive, and lay there for four hours.

Within seconds, residents of the Canfield Green apartments poured outside. They lined the police tape surrounding the scene. They yelled at officers. They took photos and videos. And they started to post the images on Twitter, Facebook and Instagram. Within hours, the picture of Brown's body and blood in the street traversed the country and spread across the world.

Then witnesses began to come forward. And the story of the struggle took shape. Early witnesses said Wilson grabbed Brown, and Brown ran away, Wilson firing after him. Brown, they said, then stopped, turned and raised his hands, as if surrendering.

Police said it was Brown who attacked Wilson.

And, just like that, residents here and across the country began to take sides.

Protesters gathered in the Ferguson streets nightly, often building to violence by the evening. Some broke into stores. The QuikTrip on West Florissant Avenue was sacked and burned.

Police responded with armored trucks, tear gas, batons, helmets and dogs. Hundreds have been arrested.

The clashes aggravated tensions.

Protesters gathered 20,000 signatures to remove McCulloch, who they doubted could be unbiased.

Nixon, too, came under fire after he refused to remove the prosecutor.

And many, from politicians to activists to pundits and residents, decried the police's militarized response to the nights of protests.

In the aftermath, the U.S. Department of Justice opened parallel investigations into Brown's shooting and into the potential of a pattern of civil rights violations in the Ferguson Police Department. At the same time, the Justice Department began working with St. Louis County Police on voluntary but intensive training on community-policing standards.

All the while, the region's residents held their collective breath, some weary of what they saw as injustice, others of the protest itself.

By Sunday, boards covered block after block of windows along West Florissant Avenue. Workers had pasted a film on jail windows at the county Justice Center in Clayton to prevent shattering glass. At least one school district canceled classes early.

But Monday brought a new flurry in the county seat.

Workers plastic-wrapped statues to prevent graffiti. Firefighters screwed plywood around the Clayton firehouse bell. The recreation center and the library both closed early. Office buildings locked down.

Businesses and public buildings across the county followed suit:

QuikTrip indefinitely closed four gas stations in and near Ferguson. COCA, the Center of Creative Arts in University City, canceled classes, events and rehearsals. Pappy's locked up early at its beloved Midtown barbecue joint.

Two of the region's major malls _ Plaza Frontenac and St. Louis Galleria _ both closed early.

And, throughout the afternoon, one school district after another called off Tuesday classes, plus Monday sports practices, board meetings and club activities.

Protesters began to gather in the early evening, across the street from the Ferguson Police Department. By the time McCulloch stepped to the podium to deliver Monday's news, the crowd had grown to a few hundred.

As he spoke, the crowd began to churn.

Historians and civil rights leaders say Ferguson represents a new consciousness in St. Louis.

"It's kind of a remarkable moment," said Margaret Garb, an associate professor of history at Washington University in St. Louis. "We haven't had a major protest and major civil rights movement in a long time."

Adolphus Pruitt, president of the St. Louis city chapter of the NAACP, said the duration and worldwide exposure of these protests have given them a unique place in St. Louis history. "I'm not sure if there's anything to measure it against," he said.

"I hate to say this," he added, "but we're still in the early stages of this one."