A man has been charged with murder after 20 people were killed and more than two dozen injured 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.
Hours later, another shooting in Dayton, Ohio, claimed nine lives. That gunman was killed by police.
Detectives sought to determine if it was written by the man who was arrested.
The border city has figured prominently in the immigration debate and is home to 680,000 people, most of them Latino.
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.
Authorities did not release his name at a news conference but said he was arrested without police firing any shots.
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.
There was no immediate indication that he had an attorney.
The district attorney said officials would seek the death penalty.
The Justice Department was weighing federal hate crime charges that would carry the potential for the federal death penalty, according to a person familiar with the department’s decision-making process.
Police say more than two dozen people were wounded in the attack at a shopping area about five miles from the main border checkpoint with Ciudad Juarez, Mexico.
Many of the victims were shot at a Walmart.
“The scene was a horrific one,” El Paso police chief Greg Allen said, adding that many of the 26 people who were hurt had life-threatening injuries.
Adriana Quezada said she was in the women’s clothing section of the Walmart with her two children when she heard gunfire.
“But I thought they were hits, like roof construction,” Ms Quezada, 39, said of the shots.
Her 19-year-old daughter and 16-year-old son threw themselves to the ground, then ran out of the store through an emergency exit. They were not hurt.
Officials said three Mexican nationals were among the dead and six more were wounded.
Ryan Mielke, a spokesman for University Medical Centre of El Paso, said 13 of the wounded were brought to the hospital, including one who died.
Two of the injured were children who were transferred to El Paso Children’s Hospital, he said.
A total of 11 other victims ages 35 to 82 were being treated at Del Sol Medical Centre, hospital spokesman Victor Guerrero said.
God bless the people of El Paso Texas. God bless the people of Dayton, Ohio.
— Donald J. Trump (@realDonaldTrump) August 4, 2019
Residents quickly volunteered to give blood to the injured. President Donald Trump tweeted: “God be with you all!”
In a document that was posted online shortly before the shooting, the writer expressed concern that an influx of Hispanics into the US will replace ageing white voters, potentially turning Texas blue in upcoming elections and swinging the White House to the Democrats.
The writer was 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 said his views on race predated Mr Trump’s campaign and that any attempt to blame the president for his actions was “fake news.”
The writer denied he was a white supremacist but the document says “race mixing” is destroying the nation and recommends dividing the US into territorial enclaves determined by race.
The first sentence of the four-page document expresses support for the man accused of killing 51 people at two New Zealand mosques in March after posting his own screed with a conspiracy theory about nonwhite migrants replacing whites.
Officers appeared to speak briefly with a woman who answered the door of the grey stone house and later entered the residence.
The shooting was the 21st mass killing in the US in 2019 and the fifth public mass shooting.
Before Saturday, 96 people had died in mass killings in 2019 – 26 of them in public mass shootings.
