Quintanilla-Vasquez was subsequently charged in Moab's 7th District Court with four counts of second-degree felony aggravated human smuggling, three counts of third-degree felony human smuggling, and one count of class C misdemeanor improper lane travel.
He made his initial appearance in court Tuesday, where his bail amount was reduced from $150,000 to $100,000, according to his defense attorney, Cara Tangaro.
Tangaro said a preliminary hearing was scheduled for June 17, where prosecutors will present evidence and a judge will rule whether there is probable cause for Quintanilla-Vasquez to stand trial on the charges.
Tangaro said Tuesday that her client "adamantly denies" that he was smuggling undocumented immigrants into the country.
"What I hope to be able to show is that my client is a victim of this whole thing, as well," Tangaro said.
Tangaro said Quintanilla-Vasquez has family members in Chicago, and wanted to go there to find work. A friend of a friend told him that a group of men were heading that way, and that he could carpool with them.
"My client showed up, and they told him that the driver decided not to come and asked him to drive," she said, adding that Quintanilla-Vasquez didn't know anyone in the van.
The Utah Highway Patrol has identified three crash victims as Freddie Sanchez-Garcia, 19; Rueben Alberto Perez- Manriquez, 32; and Efrain Morales Carteno, 30. Troopers have withheld the fourth victim's name pending family notification.
Quintanilla-Vasquez was injured in the crash, along with three others.
Investigators found no valid U.S. identification on the survivors, but the victims were carrying false documents. Their permanent resident cards lacked flags or presidential images on the backs, Social Security cards had spelling and grammatical errors, and Mexican out-of-country identifications displayed off-center photos and poorly-cut lamination, investigators wrote.
One of the survivors told investigators that Quintanilla-Vasquez had a female passenger in the front seat when he picked them up in California; witnesses saw her run from the crash scene, and she hadn't been found as of Friday, troopers said.
Charges do not indicate where in California the men were picked up. The men did not know the name of the company they would be working for, or even the industry in which they would be working, investigators wrote. The seven men hailed from Mexico and El Salvador, troopers have said.
Quintanilla-Vasquez underwent surgery at a Grand Junction hospital for injuries he suffered in the crash and had been held at the Mesa County jail in Colorado. Tangaro said that he had been extradited to Utah and was in the Grand County jail on Tuesday.
"We think that when all the evidence comes out, this is going to be a very different picture from what is being alleged now," Tangaro said. "It's a very tragic case, with four people being deceased. I think that puts some pressure on law enforcement, it puts some pressure to hurry and file charges."