Guillermo Arcángel de Pacas
Tijuana, Baja California, Mexico
Joaquín Papaqui
El Jefe
Austin Conrad
Billy and his helper, Joaquín Papaqui, haul furniture across the border into the U.S. for Muebleria Santiago.  That job, however, is a front for their other activity operating as Coyotes, smuggling illegal immigrants as part of El Sindicato del Norte.  Where Joaquín is silent and menacing, Billy is usually upbeat, smiling and cracking jokes.
From the pages of Blood Brothers:

The driver and passenger doors opened and two men climbed out. I recognized both of them from previous drops. They were both shorter than average, the driver a scrawny little thing, the passenger a bit stockier. They walked up to us.

“Austin, what’s up compadre,” said the driver, whose threadbare Padres jersey hung loosely on his wiry frame. He took a long look at my partner, then looked up at me and said, “Who’s this, Casper? He don’t look so friendly.”

“Close. He goes by Frosty,” I said, and turned to my partner. “Frosty, this is Guillermo. And…Joaquín, is it?”

The driver nodded and stepped forward, offering a hand to Frosty. “You can call me Billy. But Joaquín just goes by Joaquín. Don’t call him Jack. He hasn’t gotten in touch with his inner gringo yet.”