According to a January 2018 article in Business Insider, a group of psychiatrists studied 400 movies and identified 126 psychopathic characters. They chose Javier Bardem's portrayal of Anton Chigurh as the most clinically accurate portrayal of a psychopath.
In the novel, Sheriff Bell says of the dope-dealers, "Here a while back in San Antonio they shot and killed a federal judge." Cormac McCarthy set the story in 1980. In 1979, Federal Judge John Howland Wood was shot and killed in San Antonio by Texas free-lance contract killer Charles Harrelson, father of Woody Harrelson (Carson Wells).
When directors Joel Coen and Ethan Coen approached Javier Bardem about playing Chigurh, he said, "I don't drive, I speak bad English and I hate violence." The Coens responded, "That's why we called you." Bardem said he took the role because his dream was to be in a Coen Brothers film.
An unforeseen expense for the film was the make-up department buying expensive fake blood at $800 a gallon. Joel Coen realized why they were spending so much when it came time to film the scene where Llewelyn (Josh Brolin) stumbles across the aftermath of a shoot-out with lots of extras lying around dead in the dust. Ordinary, fake blood (made with sugar) would have meant the extras would have been crawling with bugs and ants, while the insects had no interest in the expensive stuff.
Josh Brolin broke his shoulder in a motorcycle accident two days after getting the part in this film. In an interview with NOW Magazine, he recalled thinking, "Fucking shit. I really wanted to work with the Coens," as he flew over the car that hit him. His injury, however, turned out to be a non-issue since his character is shot in the shoulder very early in the film.