“He was outside the building acting strange, making threatening comments to volunteers outside because he saw that we had an anti-Trump sign on our window,” said community organiser Ana Tiffany Deveze.
The volunteers were so concerned – four days after 22 people were killed in a mass shooting in the city – that they locked themselves inside the Casa Carmelita building and called police.
Ms Deveze, 31, said: “While we waited I peeked out the window to see if I could see what he was doing in the truck and that’s when I saw that he had put on blue latex gloves and he had a pretty big knife in his hand.”
As they attempted to warn their neighbours, two women ran past “screaming that there was a man with a gun out front,” she added.
Officers from the El Paso police department arrived moments later and detained him next to his truck.