Employees did not want to be interviewed, but shoppers said the mood in the store was grim.
"It was very somber, very somber. Terrible thing that happened," said customer Catherine Norton.
"Somber. People who knew the lady that got shot - it's gotta be hard for them," offered customer Analeen Jimenez.
Meanwhile, Apex police have idenfied the gunman. They say he was 67-year-old Mervin Carroll Mims. He had no known address and had apparently been living in his truck which had California license plates, but police believe he had been in North Carolina for a while.
Police said Mims came in to the Target store just after 11:30 a.m. Sunday and shot 58-year-old employee Guadalupe Rosas of Apex.
"What I saw was legs and a gun pointing down at her," Eyewitness Cheryl Galloway said. "He stood over her for a bit after he shot her."
Witness Justin Ley told ABC11 he was in the checkout line next to Rosas when it happened. He said there was no yelling before the shooting that happened just after Rosas opened a new register. After shooting her, Ley said Mims then pointed the gun at him and told him to "get the f*** out," and he ran.
Shoppers ran for cover as the shots rang out. In the rush to get out of the store, four people were injured. Most had bumps and bruises, but Police Captain Ann Stephens said one person suffered a fracture.
Several of customers made it out the back of the store and some hid behind a retaining wall, while others made their way through fences and into the backyards of homes behind the store.
"We asked them to come in and tried to give them some water and a minute to kind of calm down and they were all able to, you know, contact their family," neighbor Dawn Graff said.
"Nine out of 10 people in this world, if not more, are very good," neighbor Mike Wagner said. "And unfortunately, there's always somebody who's out of place and, and causes stuff like this."
Stephens said Mims was still in the store when police officers arrived. They challenged him to put down his pistol, but Stephens said he instead put the gun to his own head and killed himself.
Stephens said the investigation shows Rosas and Mims had been in a relationship that ended in 2005. Rosas had worked for Target for about two years.
Authorities have not said what triggered the violence.
The victim's family said Monday they were too distraught to talk.
In a statement, Target said:
"Target is deeply saddened by the loss of one of our team members and the tragic event that took place at our Apex, N.C., store shortly after 11 a.m. Sunday morning. The safety and well-being of our guests and team members is our highest priority. The store was immediately evacuated following the incident and we are cooperating fully with law enforcement in its investigation."
Target said counselors would be on hand to help employees deal with what happened.
According to statistics from the American Bar Association, approximately 1.3 million women and 835,000 men are physically assaulted by an intimate partner annually in the United States. More than a thousand women are murdered every year by a spouse or partner. If you're in an abusive relationship, there is help available. Victims can call the National Domestic Violence hotline. Go to http://www.ndvh.org/ for more information.