(CNN) —A 21-year-old man stepped out of his vehicle unarmed and walked up to law enforcement officials shortly after a shooting inside an El Paso, Texas, Walmart on Saturday. The massacre left at least 20 people dead and 26 injured.
He has been charged with capital murder and is being held without bond, El Paso Police Sgt. Robert Gomez said Sunday evening. He has been cooperating with investigators, Gomez said.
Sources identified the suspect as Patrick Crusius, of Allen, Texas. Police believe he authored a 2,300-word racist, anti-immigrant document that lays out a dark vision of America overrun by Hispanic immigrants.
With the hate-filled writing, which authorities called a 'manifesto,' were the words: "I'm probably going to die today."
The document was published on the online message board 8chan about 20 minutes before the shooting. It is filled with white supremacist language and racist hatred aimed at immigrants and Latinos and blames immigrants and first-generation Americans for taking away jobs.
The writer cited a fear that an influential Hispanic population in Texas would make the state a "Democratic stronghold." But he says "the Republican Party is also terrible" because the GOP is in his mind pro-corporation, which could lead to more immigration.
The author says he's held these beliefs for years, before Donald Trump became President.
Federal authorities are treating case as domestic terrorism
The Department of Justice is treating the El Paso mass shooting as a case of domestic terrorism and is "seriously considering" bringing federal hate crime and federal firearm charges which carry a possible death penalty, US Attorney John Bash said Sunday.
The shooting appears to meet the statutory definition of domestic terrorism, Bash said, as it "appears to be designed to intimidate a civilian population, to say the least."
"We're going to do what we do to terrorists in this country, which is to deliver swift and certain justice," he said.
Members of the FBI's Domestic Terrorism-Hate Crimes Fusion Cell are also investigating the shooting, FBI Special Agent Jeanette Harper said.
Harper says the agency executed three search warrants in the Dallas area Sunday morning and forensics processing and review of evidence collected at those scenes have begun.
Among the 20 victims, at least seven were Mexican nationals.
Mexican Secretary of Foreign Affairs Marcelo Ebrard said Sunday the attack was considered a "terrorist act against (the) Mexican community in the US."
"We are outraged," he said. "We do not support the culture of hate."
What his online profile looked like
A Twitter account linked to the suspect shared and retweeted President Trump's tweets, posted about the border wall and liked memes disparaging Sen. Bernie Sanders and House Speaker Nancy Pelosi. The account has seen little activity in the past two years.
On February 13, 2017, the Twitter account liked a post from an anonymous account showing Trump's name spelled out with guns. Just a couple days before, the account posted a tweet saying, "#BuildTheWall is the best way @POTUS has worked to secure our country so far!"
A Facebook account connected to Crusius had no posts and only had three public friends.
A LinkedIn profile under the name Patrick Crusius said he was a student at Plano High School.
"I'm not really motivated to do anything more than what's necessary to get by. Working in general sucks, but i guess a career in Software Development suits me well. I spend about 8 hours every day on the computer so that counts towards technology experience I guess," the profile said.
He also wrote that he worked as a bagger at a grocery store for five months until he lost his mode of transportation.
Under "activities" he wrote, "I don't really participate in extracurricular activities b/c of a lack of freedom."
Suspect's grandparents are 'devastated'
In a statement delivered by a family spokesperson, the suspect's grandparents said they were "devastated" by the El Paso incident and "pray for the victims of this tragedy."
Crusius lived with his grandparents in a house in Allen while he attended junior college at Collin College and moved out six weeks ago, his grandparents said in the statement.
He spent a few nights back at the home while his grandparents were out of town, they said.
"His drivers license and mailing address were at our house in Allen -- that connection has made us the focus of the media," the statement read. "We are talking only to law enforcement agencies and will not be making further statements to the media."
"We request the media to honor our privacy."
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