Mohammad Moghaddam, 54, had worked for Walmart for "more than a decade" and was a current employee when he took hostages at the Amarillo store just after 11 a.m., Charles Crowson, senior manager of national media relations for Walmart, told ABC News.
Further details on Moghaddam and his employment with Walmart were not immediately available.
The suspect was shot by a member of the Amarillo Police Department SWAT team at 12:22 p.m., and the initial investigation pointed to the incident as workplace violence, according to police. The hostages inside are safe, police said.
At least two Walmart employees were taken hostage. One of the hostages was a manager with whom the suspect had a work-related dispute, according to police. It is unclear how many other people were taken hostage.
"As soon as we heard about the situation at our store in Amarillo, Texas, we acted immediately," Walmart said in a statement. "All customers and our two associates who were held hostage are safe. This was a very difficult situation, and we are thankful for the quick response from law enforcement."
At least one gunshot was fired, according to an eyewitness. No one else was injured in the incident, the Amarillo Police Department said.
The Walmart was shut down as the investigation took place. Police asked people to avoid the area so officers could focus on the scene.