Ferguson Braces for Grand Jury's Michael Brown Decision

— -- Stores have boarded up their windows and civil rights groups are holding non-violence training sessions as the jittery town of Ferguson, Missouri, prepares for the grand jury verdict in the shooting of unarmed teenager Michael Brown by a police officer.

Anthony Gray, one of the attorneys for Brown's family, said today that he believes that today's testimony before the grand jury by pathologist Dr. Michael Baden suggests that "we're probably getting to the end of the witness list." Baden conducted a private autopsy on Brown on behalf of the family.

The grand jury must decide whether to bring criminal charges against Ferguson Police Officer Darren Wilson for fatally shooting Brown last August. The case has been racially charged because Wilson is white and Brown was black. The grand jury's decision has the potential for public outbursts no matter which way the jury rules, but officials are particularly concerned that no indictment could trigger a renewal of the violent protests that wracked Ferguson during the summer.

Benjamin Crump, another Brown family attorney, appealed to the protesters to remain non-violent, but he also asked for police restraint.

“To law enforcement officers who will be patrolling the streets, we would like to thank you in advance for not having a repeat" of the tactics that critics said were heavy handed.

The folks of Ferguson are wary.

"We're hearing some rather specific threats through law enforcement and customers coming in the store," John Stephenson, the general manager of Metro Shooting Supplies in nearby Bridgeton, told ABC News. "I can't take them as cast in concrete, but word is on the street they're going to be hitting gun stores."

Metro Shooting Supplies has experienced a roughly 300 percent jump in gun sales in recent weeks, Stephenson said, noting that rather than the typical 10 to 15 gun sales per day they've been selling between 30 and 50 every day for the past three weeks. He said that gun stores are reportedly targets because "very small segment of our society, the people that choose to misbehave," will try to rob the stores for ammunition.

"More and more people have gotten to the point where they're going to take matters into their hands," Stephenson said.

The store has added extra private gun lessons and state-mandated conceal carry tutorials that gun carriers must take before applying for concealed weapons licenses.

"I'm concerned for my own personal safety and I've got a wife and two daughters," Stephenson said.

Violent protests and criticism of the forceful police response kept Ferguson in turmoil for weeks after Aug. 9 shooting. Missouri Gov. Jay Nixon said this week he is determined to make sure, whatever the outcome, problems do not arise again.

"Violence will not be tolerated," Nixon said. "The residents and businesses of this region will be protected."

Gray said today that Nixon's comments were one-sided. “Law enforcement should have been equally condemned by the governor,” the lawyer said.

The St. Louis County Police, St. Louis Metropolitan Police and the State Highway Patrol are the three law enforcement agencies tasked with keeping the peace, but the National Guard will be available, Nixon said.

More than 1,000 law enforcement officers have been given more than 5,000 hours of additional training. The specifics of the training have not been revealed, but one focus was on better ways to communicate and coordinate with fire and medical response units.

"They're doing what they're supposed to be doing, as far as I can tell," said Steve Gomez, a former FBI executive and ABC News security consultant.

"They're anticipating that if there are protests and rioting, it's not going to take place in Ferguson, but in the higher end areas," Gomez said, noting that sporting venues are also areas of specific concern for law enforcement officials.

Law enforcement are not the only ones to prepare for the verdict. The co-creator of a group Millennial Activists United told the Associated Press that they organized a class that trained prospective protesters on how to take notes and shoot video of police actions.