A Mississippi man arrested for fatally shooting another man at a courthouse in a possible case of revenge was scheduled for a bail hearing Tuesday.

William A. Wells, 24, was a former firefighter who had never been in any more serious legal trouble than some traffic tickets -- until his mother was shot.

Kendrick Armond Brown was facing up to life in prison for felony drug charges under Mississippi's habitual offender law.

Madison County Sheriff Randy Tucker said Wells drove to the Madison County Courthouse Monday around 9 a.m., got out of his maroon Toyota Tundra pickup truck, walked up to the 37-year-old Brown, and shot him once in the chest with a semi-automatic handgun.

Brown, who was supposed to appear in court Monday, died there in a courtyard where crepe myrtles provided only a little shade against the merciless sun. Sheriff's deputies witnessed the whole thing from a security checkpoint inside the glass-walled, courthouse lobby, and Wells laid down his gun and surrendered as soon as they came out, Tucker said.

Why did Wells shoot Brown? Madison County District Attorney Michael Guest said Monday that authorities are investigating whether Wells was seeking revenge for the Saturday night shooting of his mother, Sherry Wells.

Canton Police Chief Otha Brown said Sherry Wells was shot while driving to work Saturday night. She drove to the Canton Police station, about 200 yards across a parking lot from where Monday's shooting took place, reported the crime, and then was taken to a hospital with a knee injury. Brown said early Monday that Canton police had no suspects. Sherry Wells was later released from the hospital.

Sherry Wells had been scheduled to testify against Brown. Earlier Monday, Guest described her as an informant. He later wrote in a text message to The Associated Press that authorities are "most definitely" investigating retaliation as a motive.

It's unclear if Wells has a lawyer at this point.

Before Monday, "he hadn't been in any trouble or anything," Chief Brown said.

Wells only had minor traffic tickets on his record, including a speeding ticket from 2009 and two tickets for improper license plates in 2013 and 2014, according to court documents. Canton Fire Chief Andrew Hughes said Wells was a firefighter for about a year before quitting in June 2014.

Hours after the shooting, a group of friends and relatives gathered at Wells' house, which shares a backyard fence with the home of his mother and father. The homes are just southeast of Canton's courthouse square, both purchased out of foreclosure by Willie B. Davis, who is married to Sherry Wells. A woman who said she was the daughter of Davis and Sherry Wells said Davis didn't want to talk.

Lebertha Luckett identified herself as Wells' girlfriend and said she'd known him since high school.

"He's a good guy," Luckett said. "I don't know what happened."

People at Brown's family home declined comment Monday. Tucker said the shooting was also witnessed by Brown's lawyer, Rusty Williard, who was accompanying him. Guest said Brown was expected to reject a plea bargain Monday in a court appearance, and that Circuit Judge William Chapman had planned to set his trial for Aug. 17.

Brown had previously served time in state prison after convictions on marijuana charges in 1998 and cocaine charges in 2003. Under Mississippi's habitual offender law, Chapman could have sentenced him to up to life in prison without parole for a third felony conviction, even though none of the crimes were violent.

Brown was released from prison the second time in November 2009. But authorities stopped actively supervising the probationer after he was shot three times in August 2010. Mississippi Department of Corrections records show that Brown was temporarily paralyzed and that after he was released from intensive care, he was unable to care for himself or work. Though Brown was indicted in February for cocaine possession and sales that authorities say took place in 2014, prison records show he successfully completed his unsupervised probation in January.

There are metal detectors inside the courthouse door, but the parking lot is open to the public and unguarded. After the shooting, officers searched with metal detectors under pine straw behind a semicircle of masonry benches overlooking a war memorial, looking for the bullet casing.

Guest said he thought there was little deputies could have done to prevent the shooting. "There would have been, in my opinion, no way this could have been stopped," Guest said.

Canton is the seat of Madison County, just north of Jackson. It's a historic antebellum town with about 13,000 people and is known for its Christmas light festival on the town square. Canton also is the home of a Nissan assembly plant that employs 6,000 people. The south end of the county is a rapidly growing suburb; the northern half is poorer.

The 1996 movie "A Time to Kill," based on John Grisham's novel, was filmed in part at the old Madison County courthouse. In the movie, a father played by Samuel L. Jackson goes to court and kills two men on trial over the rape of his daughter. That courthouse and movie set are on the Canton town square, a few blocks from the new courthouse -- the site of Monday's shooting.