FERGUSON, Mo. Protesters gathered again in Ferguson on a sultry Wednesday night and marched to the St. Louis County Justice Center in Clayton, where a grand jury has begun examining the case.

After sunset Wednesday, more than 100 protesters gathered on West Florissant Avenue at Canfield Drive in Ferguson, scene of nightly protests, frequent disruptions and occasional looting since the shooting death on Aug. 9 of Michael Brown, 18, by Ferguson Police Officer Darren Wilson.

The steamy evening, with a temperature of 84 and 72 percent humidity at 8 p.m., took its toll on the early energy level. Adding to the discomfort was a heavy thunderstorm passing through.

A pair of protesters supporting Wilson walked along West Florissant shortly before the rain struck. Many in the crowd shouted at them, and police quickly removed them by squad car.

Another protester, Mubarack Sulamann, traveled from Memphis, Tenn., to Ferguson to peddle T-shirts that read "Justice for Mike Brown." The cost? $10.

The first of two marches in Clayton was held in the morning as the grand jury commenced its work. But County Prosecutor Bob McCulloch warned that it won't finish its task any time soon, despite numerous calls by protesters and some public officials for speedy action.

"Our target date is, hopefully, by the middle of October," McCulloch said. "I certainly understand the concern, but we won't rush it through. In the long run people, at least a majority of people, will appreciate the thoroughness."

Grand juries work in secret. The grand jury meets in McCulloch's office behind secure doors in the County Justice Center, across South Central Avenue Carondelet Avenue from the St. Louis County Courthouse. Reporters have no ability to see anyone entering or leaving the grand jury room, or how they get to McCulloch's office from outside the building.

Handling the case before the grand jury are assistant prosecutors Sheila Whirley, who is black, and Kathi Alizadeh, who is white. Alizadeh, with 27 years experience, is the regular homicide prosecutor. Whirley has the grand jury assignment and 18 years experience.

McCulloch declined to discuss any evidence, but elaborated upon his decision not to rush the investigation.

"Some people say we are rushing to judgment and others say we are dragging it out," he said. "We will do this as expeditiously as possible, but certainly not in any haphazard manner."

As for October, he said, "It could be longer than that, or shorter than that. I doubt any sooner than that."

Outside the Justice Center, about 50 protesters marched and chanted in the 7800 block of Carondelet Avenue. One held a sign saying, "Recuse McCulloch."

The only tense moment was when Pattie Canter of Clayton walked to the protest area carrying a sign saying, "My family and friends support Officer Wilson and the police."

Chanting "What about police rights?" and "Police officers have rights, too," Canter walked near the protesters, some of whom shouted, "Go home! Go home!"

Replied Canter, "I have constitutional rights. I'm not going anywhere."

As the crowd became more agitated, police officers escorted her to a police vehicle. Canter told a reporter she was not under arrest. "Why would I be?" she said before being driven away.

On Wednesday evening, a second march of about 100 people returned to the Justice Center after walking eight blocks from Clayton High School. The clergy group that organized the march called for replacement of McCulloch with a special prosecutor, "an expedited grand jury hearing to indict Officer Darren Wilson" and an investigation into racial profiling.

Participants sang and carried signs saying, "Black lives matter," and "Taser, then talk." A few officers stood outside the Justice Center when the marchers arrived.