The teenager practiced driving from his apartment in San Diego down to Tijuana and back, on the orders of the criminals he was working for in Mexico.
He rehearsed how he would respond to questions from U.S. border officers.
The men who were paying him had cut a secret compartment into his car big enough to fit several bricks of fentanyl.
When they loaded it up for the first time and sent him toward the border, Gustavo, who was only 19 at the time, began to tremble.
At the checkpoint, he steadied himself like he had practiced, and calmly told the border officers that he was just heading home.
Persons:
Gustavo, steadied
Locations:
San Diego, Tijuana, Mexico