Trouble was brewing in Sanford.

An African-American teen was dead, shot in the chest. The shooter, a neighborhood watch captain, said he acted in self-defense. The black community, long wary of the police department, was demanding an arrest. There was talk of protests and marches. National civil rights leaders had taken up the cause. The media was descending, bringing its harsh spotlight.

Quite suddenly, the tiny Central Florida city, just north of Orlando, was being cast by some as racially troubled.

So in the weeks after the Feb. 26, 2012 shooting death of Trayvon Martin, a city representative picked up the phone and called Thomas Battles, a quiet force who has worked almost three decades mending racially damaged communities.

The federal mediator works for the U.S. Department of Justice Community Relations Service (CRS), a stealth federal operation that works to defuse community anger hardening along the fault lines of race, color and national origin.

The mediators are called the peacemakers.

“There was so much angst and fear of the unknown,” said Sanford Mayor Jeff Triplett one afternoon just after the start of the murder trial of George Zimmerman, accused in the shooting death of Trayvon Martin. “We had never been through something like this before. We didn’t know what was going to happen and if this thing was going to blow. Mr. Battles has a calming way about him. He was a voice of reason. He got everybody to the table.’’

Battles, southeastern regional director of the CRS, acted as a trusted third party, gathering opposing factions to address the simmering tension by developing reconciliation strategies. He worked with city and civic leaders to allow the protests, but in peaceful manner. He also worked with the city to create its nine-point plan that aims to improve race and police relations, and tapped into the city’s faith community to help guide the healing.

Now, with the Zimmerman trial expected to end in the next week or so, Battles, based in Atlanta, is likely headed back to Sanford to make sure the verdict — acquittal or conviction — does not incite violence. By department policy, Battles does not give media interviews.

“Like all our conciliators, Thomas Battles goes into a heated community to be supportive, to listen and mediate and to slow things down for people,’’ said Grande Lum, director of the CRS. “They help to create reasonable conversations.’’

Reserved and discreet, yet engaging and well-connected, Battles and his team were dispatched to the city as the shooting was making national headlines — to assist without drawing attention to themselves.

“He and his staff largely operate out of the spotlight doing very important, very necessary work,’’ said Mark Potok, a senior fellow at the Southern Poverty Law Center, where Battles and his team have received training. “They are going to cities like Sanford that are torn apart by a racial rift, put in an international spotlight. These are places that need help quickly.’’

The CRS was established by the Civil Rights Act of 1964 to act as a “peacemaker” in communities with tension from race, color and national origin-related conflicts. It is the only federal agency dedicated to working with state, local officials as well as community groups in, “restoring racial stability and harmony.” Four years ago, the agency’s mission was broadened to include hate crimes related to gender, gender identity, sexual orientation, religion and disability.