With a grand jury expected to announce a decision this month on unarmed teenager Michael Brown's death, Darren Wilson, the Ferguson, Missouri, police officer accused of fatally shooting the 18-year-old, is reportedly confident that he won't be facing criminal charges for the case, a police union official revealed Thursday.

Ever since the Aug. 9 shooting of the 18-year-old Brown happened, 28-year-old Wilson has been granted paid administrative leave to be hidden following weeks of violent protests that rocked the Ferguson community, the Associated Press reported.

The shooting, which drew national attention, has reignited a racial debate over how police treat young black men in the United States. While two-thirds of the residents of Ferguson are black, the police force is almost entirely white.

But in a meeting with the suburban St. Louis police officer on Thursday, the accused cop appeared confident about the outcome of the grand jury investigation, despite being under a lot of pressure and stress, said Jeff Roorda, business manager for the St. Louis Police Officers' Association.

"It's fair to say that neither he nor his defense team expect an indictment," Roorda said, offering his impression of the situation based on the meeting with Wilson.

However, later on, Roorda told the AP that he was only speaking for himself.

"Wilson seems confident that justice will be served, but neither he nor his attorneys shared any expectations with me," he said in a text message.

In addition, one of Wilson's attorneys, who also attended Thursday's meeting, confirmed that there had been no specific discussion of expectations, News.com.au reported.

"We have absolutely no idea - no more than anyone else - what may or may not happen. The only expectation that we would have is that the grand jury would be thorough and fair," attorney Neil Bruntrager said, adding that if Wilson was indicted, the police officer was ready to immediately turn himself in to authorities.

Earlier this week, Missouri Gov. Jay Nixon declared a state of emergency and authorized the state's National Guard to support police in case of violence.

The order, in effect for 30 days, instructs the St. Louis County Police Department, the Missouri State Highway Patrol and the St. Louis Metro Police to work together in policing violent protests that might erupt after a decision is announced.

Currently, the 12-person St. Louis County grand jury, which meets only once a week on Wednesdays, is still hearing evidence on whether to indict Wilson, who could face varying degrees of charges, a spokesperson for St. Louis County Prosecutor Bob McCulloch's office told News 4 on Thursday.