Profile: Texas shooter was a loner and a rambling white supremacist
The El Paso shooting suspect is a 21-year-old white supremacist who claimed that Texas was being "invaded by Hispanics" in a rambling online manifesto.
Patrick Crusius, the alleged killer, lived in Allen in Dallas, roughly a 10-hour drive from the mall where his killing spree unfolded.
According to ABC News, he told law enforcement officials after his arrest that he wanted to shoot as many Mexicans as possible.
The manifesto was published online shortly before the attack began, praising US President Donald Trump and a far-right terrorist behind a similar mass shooting in Christchurch, New Zealand, in March.
"This attack is in response to the Hispanic invasion of Texas. They are the instigators, not me," claims the killer in the manifesto.
It also alludes to the white genocide conspiracy theory, sometimes known as the "Great Replacement", a debunked claim that mass migration from Africa and the Middle East will render white populations extinct.
"I know that the media will probably call me a white supremacist anyway and blame Trump's rhetoric. The media is infamous for fake news. Their reaction to this attack will likely just confirm that," an extract reads.
Former classmates and neighbours told the 'LA Times' Crusius was a loner who had a "short temper".
Mr Trump has made racist comments about Mexican migrants, including a claim that they are predominantly rapists and drug dealers.
He has also threatened raids against immigrant families and removed children from families who cross from Mexico without papers.
The writer was also critical of Republicans for what he described as close ties to corporations and degradation of the environment.
According to the FBI, the killer's manifesto was uploaded to social media websites 4chan and 8chan just an hour before the shooting.
The killer appears to have mimicked the rhetoric and behaviour of Brenton Tarrant, the Australian far-right terrorist who opened fire at a mosque in Christchurch, killing 51 people.
Veronica Escobar, who represents El Paso in Congress, said yesterday "the manifesto narrative is fuelled by hate... And it's fuelled by racism and bigotry and division".
Witnesses described the gunman as a white man dressed all in black, with his face covered and armed with an assault rifle.
Vanessa Saenz, a Walmart shopper, said he was wearing a black T-shirt, cargo pants and ear protectors.
She said it looked like he was "dancing".
"The one thing I'll never forget is the way he walked into Walmart, very confident. He was on a mission and that's when it hit me," she said. (© Daily Telegraph, London)