Video report by ITV News Security Editor Rohit Kachroo
A man has been charged with murder after 20 people were killed and more than two dozen injured in a shooting that's being treated as domestic terrorism in Texas.
The gunman, armed with a rifle, opened fire in an El Paso shopping centre packed with as many as 3,000 people during the busy back-to-school season.
Authorities were investigating whether Saturday's attack was a hate crime after the emergence of a racist, anti-immigrant screed that was posted online shortly beforehand.
A picture of the suspect, 21-year-old Patrick Crusius, has been released.
Detectives sought to determine if the document, which used white supremacist language, was written by the man who was arrested in El Paso - a city with a large Hispanic population.
A 25-year-old woman who was shot while shielding her two-month-old son was among the 20 people killed, according to her sister.
Leta Jamrowski, 19, learned on Saturday afternoon that her sister Jordan Anchondo had been shot dead at Walmart while shopping for back-to-school supplies earlier in the day.
Ms Jamrowski spoke as she paced a waiting room at the University Medical Centre of El Paso, where her two-month-old nephew was being treated for broken bones as the result of his mother’s fall.
Police said another 26 people were injured, with most of the victims believed to have been shot at a Walmart in a busy shopping area near the Cielo Vista Mall.
Federal authorities were treating the attack as a domestic terrorism case, according to the US attorney.
Despite initial reports of possible multiple gunmen, the man in custody was believed to be the only shooter, police said.
He is from Allen, which is a nearly 10-hour drive from El Paso.
The suspect was booked on capital murder charges, according to jail records, which means his alleged crimes could see him sentenced with the death penalty.
There was no immediate indication that he had an attorney.
The district attorney said officials would seek the death penalty.
“The scene was a horrific one,” said El Paso Police Chief Greg Allen, who added that many of the wounded had life-threatening injuries.
El Paso Mayor Dee Margo said police were investigating whether a document posted online shortly before the shooting was written by Crusius.
In it, the writer expresses concern that an influx of Hispanics into the United States will replace ageing white voters, potentially turning Texas blue in upcoming elections and swinging the White House to the Democrats.
The writer is also critical of Republicans for what he described as close ties to corporations and degradation of the environment.
Though a Twitter account that appears to belong to Crusius included pro-Trump posts praising the plan to build more border wall, the writer of the online document says his views on race pre-dated Mr Trump’s campaign and that any attempt to blame the president for his actions was “fake news”.
President Trump has offered prayers for the shooting victims in both El Paso and Dayton and ordered that flags should be lowered to half-mast on government buildings until August 8.
Although the writer denied he was a white supremacist, the document says “race mixing” is destroying the nation and recommends dividing the United States into territorial enclaves determined by race.
In the hours after the shooting, authorities blocked streets near a home in Allen, Dallas, associated with the suspect.
Officers appeared to speak briefly with a woman who answered the door of the grey stone house and later entered the residence.
Following the shooting, residents volunteered to give blood to the injured, while police and military members were trying to help people who were looking for missing loved ones.
“It’s chaos right now,” said Austin Johnson, an Army medic at nearby Fort Bliss, who volunteered to help at the shopping centre and later at the school that was serving as a reunification centre.
Adriana Quezada, 39, said she was in the women’s clothing section of Walmart with her two children when the shooting happened.
“I heard the shots but I thought they were hits, like roof construction,” she said.
Her 19-year-old daughter and 16-year-old son threw themselves to the ground, then ran out of the Walmart through an emergency exit. They were not hurt, Ms Quezada said.
The suspect, who used a rifle, was arrested without incident. Police believe he was the sole gunman but are continuing to investigate reports that others were involved.
The mass shooting in El Paso came less than a week after a gunman opened fire on a California food festival.
Ryan Mielke, a spokesman for University Medical Centre of El Paso, said 12 people were brought to the hospital with injuries, including one who died.
Two of the injured were children who were being transferred to El Paso Children’s Hospital, he said. He declined to provide additional details on the victims.
Eleven other victims were being treated at Del Sol Medical Centre, according to hospital spokesman Victor Guerrero. He said those victims’ ages ranged from 35 to 82.
Texas governor Greg Abbott called the shooting “a heinous and senseless act of violence” and said the state had deployed a number of law enforcement officers to the city.
“Reports are very bad, many killed,” US president Donald Trump tweeted.
Presidential candidate and former Texas congressman Beto O’Rourke appeared a bit shaken as he appeared at a candidate forum in Las Vegas, shortly after news of the shooting in his hometown was reported.
Mr O’Rourke, who said he had called his wife before going on stage, said the shooting shattered “any illusion that we have that progress is inevitable” on tackling gun violence.
El Paso, which has about 680,000 residents, is in West Texas and sits across the border from Juarez, Mexico.
The city has become a focal point of the immigration debates.
This is the 21st mass killing in the United States in 2019, and the fifth public mass shooting. Before today, 96 people had died in mass killings in 2019 — 26 of them in public mass shootings.