A capital murder charge was officially filed against the man accused of killing 20 people and injuring 26 others in a mass shooting at a busy Walmart in El Paso, Texas.

Law enforcement officials said they arrested a 21-year-old Dallas-area man in connection to the deadly shooting and are treating the shooting as a domestic terrorism incident. Some of the mayhem was posted to social media showing shoppers scrambling for cover and their hands raised.

The shooting comes just days after two people were shot and killed in a Walmart store in Southaven, Mississippi, south of Memphis, and the same week three people were killed at a shooting at the Gilroy Garlic Festival in California.

Here's what we know about the El Paso shooting right now:

Where did the shooting take place?

During a news conference, Sgt. Robert Gomez said the attack occurred at a Walmart near the Cielo Vista Mall in El Paso, a heavily Hispanic Texas city situated at the U.S.-Mexico border which sees thousands of Mexican shoppers on a daily basis. The first calls came in at 10:39 a.m. MDT, and the first officer arrived six minutes later in what would become a massive response, according to El Paso Police Chief Greg Allen. The Walmart location, according to Gomez, was "at capacity" during the busy shopping weekend and estimated that up to 3,000 shoppers and about 100 employees were at the store.

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How many victims are there?

At least 20 people were killed and 26 others were wounded during the shooting, Texas Gov. Greg Abbott and El Paso police said, the Associated Press reported. Citing the investigation and pending next of kin notifications, authorities have not released the victims' identities, CNN reported. Late Saturday, the Mexican government said at least three Mexican nationals were killed and six were injured in the mass shooting. Mexican President Andres Manuel Lopez Obrador tweeted a video offering his condolences to victims and made note of the close ties the border cities share, including the impact of the shooting on both communities.

The University Medical Center of El Paso received 13 victims, ranging in age from 2 to senior citizens, the hospital said Saturday. Del Sol Medical Center received 11 victims ages 35 to 82. Two are stable, nine are critical and three of those are in "a life-threatening predicament," the hospital said.

The death toll in the El Paso shooting increased to 22 on Monday. There are now 24 injured.

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What's the latest info on the shooter?

The suspect, identified by two law enforcement sources as Patrick Crusius, 21, of Allen, Texas, surrendered to officers and was being interviewed, police said. Crusius, who is white, was booked into the El Paso County Jail early Sunday morning on a charge of capital murder.

A charge of capital murder holds a punishment of death or life in prison without parole. No bond has been set for Crusius, jail logs show.

"The state charge is capital murder and so he is eligible for the death penalty," District Attorney Jaime Esparza told a press conference. "We will seek the death penalty."

U.S. Attorney John Bash said federal authorities were treating the shooting as a domestic terrorism case and were "seriously considering" hate crime charges.

According to records, Crusius graduated high school in 2016. He enrolled in Collin College in the fall of 2017, according to the college, and was enrolled as a student until the spring of 2019. "We join the governor and all Texans in expressing our heartfelt concern for the victims of the shooting and their loved ones," the college released a statement on Twitter.

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Where does the investigation stand?

Investigators believe Crusius posted a 2,356-word "manifesto" that appeared on the anonymous message board 8chan less than a half hour before the shooting. El Paso Police Chief Greg Allen says police are attributing the "manifesto" directly to Crusius.

In the post, the writer expresses concern that an influx of Hispanics into the United States will replace aging white voters, potentially turning Texas blue in upcoming elections and swinging the White House to the Democrats. Hours after the shooting, authorities blocked streets near a home in Allen associated with the suspect.

Officers appeared to speak briefly with a woman who answered the door of the gray stone house and later entered the residence, according to the Associated Press. Late Friday, the FBI in El Paso took to Twitter "asking anyone that took video or pictures" of the shooting to submit them to authorities.

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How did lawmakers react?

Local and federal officials were left stunned but condemned the shooting.

"Our community will not be defined by this senseless evil act of violence," El Paso Mayor Dee Margo said, according to CNN. "United our community will heal. El Paso is too strong to be broken by a cowardly act like this."

President Donald Trump responded on Twitter, calling the shootings an "act of cowardice" and pledged the federal government's help in another.

Abbott, who pledged to "aggressively prosecute" the shooting as "both as capital murder, but also as a hate crime," said that "crimes like this are not who or what Texas is and will not be accepted here."

In Las Vegas for a presidential forum, former Rep. Beto O’Rourke addressed the mass shooting that hit his hometown.

"We know that a lot of injury, a lot of suffering in El Paso right now," said O'Rourke, who is a candidate for the Democratic presidential nomination. "I am incredibly saddened, and it is very hard to think about this."

The incident also sparked the debate on gun control.

"While we are grateful for heroic first responders, our hearts ache for the families of those who were killed and the injured. Action must be taken to finally end gun violence," House Speaker Nancy Pelosi said on Twitter.

Contributing: El Paso Times; and Associated Press