The testimony came in the trial of Laurence Lovette - one of the men accused of killing Carson.
Lovette's defense team did not want Carolina Harper to testify, so the judge let attorneys first question her outside the presence of jurors before testifying again before them.
The 23 year old told jurors she was sitting in her car arguing with her boyfriend on the phone around 3:30 a.m. on March 5, 2008 outside her sorority house not far from where Carson lived.
Harper said she saw the men about 15 feet behind her car, that they were in their late teens to early 20s, and were staring at her.
"I immediately was extremely frightened, so I threw the car in reverse and backed up and pulled forward out of driveway," she said.
Carson was abducted about 15 minutes later from her home on Friendly Lane, according to investigators. Less than two hours later, residents of a Chapel Hill neighborhood heard shots ring out. Carson was found dead in the street.
Lovette, who was 17 at the time, was arrested in the following days along with Demario Atwater.
Pictures of possible suspects were captured by a camera in an ATM where Carson's bank card was used. The picture fits Harper's description of the men she says she saw.
Asked by prosecutor James Rainsford if she saw what they were wearing, Harper said: "Yes, baggy dark clothing. It was a hooded sweatshirt or jacket, and, I think a baseball cap."
The judge allowed Harper's testimony but over the objections of Lovette's attorney who said Harper only told police that she saw two black men and that she later added the other details after the ATM pictures were all over the news.
In opening statements Wednesday, District Attorney Jim Woodall told jurors that Lovette is the man in the ATM photos. He also told them that Atwater's girlfriend Shanita Love will testify that the men got rid of two guns after the murder. Woodall said she led detectives to parts of a handgun that was later linked through ballistics testing to two bullets found in Carson's body.
Woodall said Love will also testify that Lovette and Atwater destroyed a sawed off shotgun detectives believe was used in the murder. Detectives later recovered that gun and found Atwater's DNA under duct tape wrapped around the weapon.
But in her opening statement, defense attorney Karen Bethea-Shields pointed all the blame at Atwater and said there is no forensic evident linking Lovette to the actual killing.
She also said witnesses for the prosecution expected to tie Lovette to the murder have "interest, bias, and motivation."
An autopsy revealed that Carson - originally from Athens, GA - was shot five times.
Last year, Atwater pleaded guilty to federal carjacking charges and state charges that included first-degree murder, first-degree kidnapping, and armed robbery. The plea agreements spared him a death sentence but sent him to prison for life.
Lovette faces the same fate if he's convicted, because the death penalty is not an option due to his age at the time of the killing. He's charged with first-degree murder in the Carson case.
Lovette is also accused in taking part in the killing of Duke University graduate student Abhijit Mahato in January 2008 along with Stephen Lavance Oates.
Mahato was a 29-year-old doctoral student in computational mechanics originally from Tatangar, India. He was fatally shot inside his apartment near Duke's campus. His wallet, cell phone, and iPod was taken.