The man suspected of opening fire on shoppers in Texas, killing at least 20 people and injuring dozens more, has been named by US media as 21-year-old Patrick Crusius.

He is from the Dallas suburb of Allen, about a 10-hour drive from the scene of the shooting in El Paso.

Image: Police say they are investigating whether the shooting was a hate crime

In CCTV footage, the gunman appears to be wearing dark clothing, glasses and ear muffs as he enters the Walmart.

Initial reports said the suspect had an AK47, although this has not been confirmed by police.

Officers are investigating whether the shooting was a hate crime intended to target the city's largely Hispanic population.


Image: The shooting is the eighth deadliest in US history

US media reports authorities are "reasonably confident" the suspect was behind an online post published shortly before the attack, which expressed racist and anti-immigrant views.

The post is being investigated by the FBI.

Speaking at a press conference, US representative Veronica Escobar said: "Not speaking about this particular incident, which is still under investigation, but the manifesto narrative is fuelled by hate, and it's fuelled by racism and bigotry and division."

Law enforcement officials told ABC News the suspect told them he wanted to kill as many Mexicans as possible.

US President Donald Trump reacts to news of another mass shooting in the US

Eyewitness Vanessa Saenz told Fox News the gunman seemed "very nonchalant, like he was on a mission".

She said he was "just pointing at people and shooting straight at them" and appeared to be shooting "randomly".

Following the attack, authorities blocked streets near a home in Allen associated with the suspect.

Officers spoke briefly with a woman who answered the door at the house and later went inside.

Texas politician Jeff Leach said in a tweeted statement that Crusius graduated from Plano Senior High School in 2017.

Collin County community college, which has campuses across Texas, also confirmed he had attended there earlier in 2019.

A LinkedIn user named Patrick Crusius, which lists Plano Senior High School, wrote on their page that they were "not really motivated to do anything more than what's necessary to get by".

Crusius' former neighbour, Leigh Ann Locascio, told the Los Angeles Times he was "very much a loner".