Walter Scott's Mother Emotional on the Stand in 1st Day of Murder Trial for Former SC Cop Michael Slager

— -- In the first day of testimony in the South Carolina criminal trial of Michael Slager, the white former police officer accused of fatally shooting Walter Scott, an unarmed black man, Scott's mother was emotional on the stand, recounting her phone conversation with her son as he was pulled over by police.

Slager is accused of killing Scott after a traffic stop in North Charleston in April 2015. Slager was an officer with the North Charleston Police Department at the time and says he stopped Scott’s car because a brake light was out. Slager, who was later fired from the police force, was charged with murder last year after witness video of the incident surfaced and appeared to show the moment he fatally shot Scott from behind as he ran away. Slager has pleaded not guilty.

Slager is also awaiting trial in federal court, charged with violating Scott’s civil rights, using a firearm during the commission of the civil rights offense and obstruction of justice.

In opening statements in a Charleston courtroom this morning, Ninth Circuit Solicitor Scarlett Wilson, the prosecutor for Charleston County, argued to the jury that the former cop acted with malice and forethought before he allegedly fired multiple rounds into Scott’s back.

“An unarmed man shot eight times. Eight times,” Wilson said slowly, emphasizing each word.

Wilson said Slager’s “first instinct” was to lie about the incident by claiming that, at the time he fired his weapon, Scott was coming toward him with a Taser that Scott had managed to take from him. She said Slager staged the crime scene by allegedly dropping the Taser near Scott's body.

“It was wrong,” Wilson told the court.

Slager's attorney, Andy Savage, in opening statements explained the dangers police officers face each day on duty. He said Slager was tasked with patrolling the most “crime-ridden area” in North Charleston, describing the 25 pounds of protective gear Slager put on when suiting up for the job.

During his five-year career with the North Charleston Police Department, Slager did not issue a ticket for 98 percent of traffic stops he made for equipment failure, according to Savage. The defense attorney argued the same would have likely happened for Scott if it weren’t for decisions he allegedly made during a confrontation with Slager.

Savage argued that Slager did not have malice with forethought. He said Scott fought with Slager and took away the Taser. According to Savage, the former police officer didn't know whether Scott was armed because he didn't have the chance to pat him down.

"I’m convinced that this was not a malicious, deliberate plan," Savage said.

Scott's mother, Judy Scott, was emotional on the stand as she recounted the day of her son's death. She said she was in a car, driving one of her grandsons, when Walter Scott called her saying he was being stopped by police.

"He didn't sound very good at all," Judy Scott said. "He sounded in distress."

"All I heard was, 'Get on the ground and put your hands behind your back,'" she said.

She said she heard her son say, "they Tasing me."

"And I heard him groaning like he was in excruciating pain a couple of times," Judy Scott said. "I said, 'Just do whatever the officers say.'"

She said she did not hear a gunshot. She also said her grandson was very upset in the car.

Slager's dashcam video was played in court today, showing Slager pull Scott over, Slager standing at Scott's driver-side door and Slager walking away from Scott's car. In the video, Scott then opens his driver-side door, Slager tells him to stay inside and Scott closes his door. Then, Scott opens his car door again, and Scott is seen running out of frame of the video. Slager can be heard on the dashcam video yelling "Taser, Taser."

Scott's family was emotional as the dashcam video was played for the first time and tissues were passed around in court. Scott's girlfriend, Charlotte Jones, broke down crying right after the part of the video in which the Taser can be heard.

Sgt. Scott Hille of the North Charleston Police Department said during cross-examination that it is "good practice" during a traffic stop for an officer to keep the person pulled over at his or her own car.

Pierre Fulton, the passenger in the car with Scott during the traffic stop, also testified. When asked why Scott ran, Fulton said, "That is a question I would like to ask him, but unfortunately he was murdered."

Scott's 22-year-old son, also named Walter Scott, was the first witness called by the prosecution. The younger Scott, a college student, said he last saw his father the morning of April 4, 2015 -- the day of the shooting. He said he was on his way to church when he got a call from his grandmother about his dad being stopped. Instead of going to church, he went to the scene of the traffic stop.

In cross-examination, the younger Walter Scott said he knew his dad used cocaine and drank alcohol and he knew his dad had a bench warrant for him.

Jones, who had dated Scott, was the second witness on the stand. She said she knew Scott had child support issues. During cross-examination by the defense, she said she didn’t know about all of his bench warrants. When asked if Scott ever expressed to her that he was afraid to go back to jail because he owed child support, she said no. When asked if she knew why Scott assaulted Slager, she said, “He wasn’t that kind of person.” He was a “kind person," she said.

Slager was released from prison on bond in January and placed under house arrest. In court today, Judge Clifton Newman granted that Slager can remain free on bond during the trial.

A nearly all-white jury was selected Wednesday. The primary panel consists of six white men, five white women and one black man. The alternates consist of two white men, two white women and two black women.

ABC News’ Katie Conway and Kristen Johnson contributed to this report.