This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

EL PASO, Texas — The suspect in a shooting at an El Paso shopping center Saturday is Patrick Crusius, 21, of Allen, Texas, three sources have told CNN.

Two federal law enforcement sources and one state government source confirmed the suspect’s identity. The federal sources said investigators are reviewing an online writing posted days before the shooting that may speak to a motive. The online posting was believed to be written by Crusius, the sources said, but that has not been confirmed.

In a news conference, Sgt. Robert Gomez of the El Paso Police Department told reporters the suspect in custody is a white male in his 20s.

Multiple people were killed Saturday in a shooting at a shopping center in El Paso, Texas, according to local officials.

El Paso Mayor Dee Margo and police Sgt. Enrique Carrillo said there were multiple fatalities.

Authorities do not believe there is an ongoing threat, Carrillo told reporters.

One suspect is in custody, according to Sgt. Robert Gomez.

At least 23 people were injured, spokesmen from two hospitals told CNN.

Eleven victims were transported to the Del Sol Medical Center, hospital spokesman Victor Guerrero said. Nine of them are in critical but stable condition, he said.

Thirteen people were taken to the University Medical Center of El Paso, spokesman Ryan Mielke told CNN, and one of them has died.

Police began receiving reports of an active shooter around 10 a.m. (noon ET), Gomez said in a brief news conference at the scene. Authorities were initially given multiple possible locations for the shooting, Gomez said, at a Walmart and the Cielo Vista Mall next door.

They also received reports of an incident at a second mall, several miles away from the Cielo Vista mall, but they confirmed that scene was safe.

“This is a large crime scene, a large area,” Gomez said. “So we are systematically going through it and making sure that anybody in the area — number one, we’re ruling out that no one is a suspect, and we’re also making sure that those people that were separated or hurt are getting the care that they need.”

A family reunification center has been set up for families who might have been separated at MacArthur Elementary School, Gomez said.

Multiple agencies, including the FBI, and the local sheriff’s department, have responded to the scene to assist El Paso authorities.

“This was a massacre,” US Rep. Veronica Escobar, who represents the area, told CNN’s Wolf Blitzer. Escobar has received conflicting reports on the numbers of casualties, she said, but added, “The numbers are shocking.”

‘You don’t think it could happen here’

Walmart issued a statement regarding the shooting, saying, “We’re in shock over the tragic events at Cielo Vista Mall in El Paso. … We’re praying for the victims, the community & our associates, as well as the first responders.”

At least three businesses were on lockdown in the area, about three miles south of El Paso International Airport.

Three Walmart employees took refuge at a nearby Landry’s Seafood house, restaurant manager Oscar Collazo told CNN. The women appeared “shook up” but not injured.

Landry’s had already gone on lockdown, he said, but opened its doors when the employees ran there.

“We never thought it would be so close to us this time,” Collazo said. “You see on the news all the time, but you don’t think it could happen here until it does.”

The nearby Hooters and Red Lobster were also on lockdown. Employees at those restaurants told CNN they were safe and saw a lot of police, helicopters and people running around outside.

In a shaky Snapchat video aired by CNN, a woman holding the camera frantically runs with a small group of girls or women through a Cielo Vista mall department store and into a parking lot.

As the group hurries past racks of clothes and cases of merchandise, voices off camera shout, “Hands up!”

Once in the parking lot, one member of the group asks, “What happened?”

“I don’t know,” the woman holding the camera responds. “I don’t know.”

White House pledges ‘total support’

President Donald Trump has been briefed on the shooting, and the White House is monitoring the situation, Deputy Press Secretary Steven Groves said in a statement.

“Terrible shootings in El Paso, Texas,” the President tweeted Saturday afternoon. “Reports are very bad, many killed. Working with State and Local authorities, and Law Enforcement. Spoke to Governor to pledge total support of Federal Government. God be with you all!”

Democratic presidential candidate Beto O’Rourke, who once represented the area in Congress, addressed the shooting while at a speaking event in Las Vegas.

“We know there is a lot of injury, a lot of suffering in El Paso right now,” he said. “I am incredibly sad and it is very hard to think about this.”

“But I’ll tell you, El Paso is the strongest place in the world,” he added. “This community is going to come together.”

O’Rourke said he would be cutting short his trip to Las Vegas to return to El Paso.

Texas Gov. Greg Abbott tweeted that the state Department of Public Safety is assisting local law enforcement.

The scene is unfolding in the same week two employees were fatally shot at a Walmart store in Southaven, Mississippi, and three people were shot and killed at the Gilroy Garlic Festival in California.