Updated: 08/21/2014 12:12 AM
Created: 08/20/2014 11:03 PM KAALtv.com
By: John Doetkott
(ABC 6 News) -- On Wednesday, a grand jury began hearing evidence in the shooting death of an unarmed black teenager by a white police officer in Ferguson, MO.
It could take weeks before the grand jury decides whether charges will be filed against Officer Darren Wilson.
Authorities say 18-year-old Michael Brown tried to take away Wilson's gun. A source tells ABC News that Wilson had a "serious facial injury." Witnesses say Brown had his hands in the air when he was shot and told the officer he was unarmed and to stop shooting.
Attorney General Eric Holder arrived in Ferguson on Wednesday hoping to ease tensions after 51 people were arrested since Tuesday.
Officials said it’s been far calmer than previous days, but protestors insist they're not backing down.
At times the protests have turned violent with rocks, bottles, even molotov cocktails thrown at police officers.
But law enforcement agencies have also been criticized for how they've handled the protests and the military-style equipment used.
Last week Missouri National Guard troops arrived in Ferguson in Humvees, but increasingly American police departments already have their own military style vehicles.
Earlier this year, the Austin Police Department received an armored Humvee at no cost through a military surplus program, and the Rochester Police Department has a mine-resistant MRAP vehicle.
The Star Tribune estimates Minnesota law enforcement agencies have collected over 8,500 pieces of surplus military equipment, drawing stark criticism from many who see the trend as a step in the wrong direction.
"The militarized weapons and the vehicles were never intended to be used in our streets against our citizens," said Chuck Samuelson, executive director of the ACLU of Minnesota.
Samuelson said the mine-resistant vehicles in particular have no place in our society.
"The only way for peace officers to function is if they're in the community and they do community policing,” Samuelson said. “This is 180 degrees off from that."
Officials in Austin said they've only used their Humvee a handful of times, including a January standoff with a burglary suspect that lasted nine hours.
Those in law enforcement said the vehicles merely offer protection and are necessary to keep officers safe.
"I can understand when you have a machine that looks like this, but the fact of the matter is it's very similar to body armor that officers are wearing,” said Det. Todd Clennon of the Austin Police Department.
"Anything that will help us do our job better and protect our officers and the public safety, we want to utilize those assets,” said Austin Police Chief Brian Krueger.
Police in Mason City, IA, also received an MRAP back in April, and Rochester Police Chief Roger Peterson said it's not an issue of where the equipment comes from, but when and how it’s used.
Chief Peterson said following those guidelines helps them keep their officers and the community safe.