More than two dozen Thai farm laborers Monday signed a letter to U.S. Attorney General Eric Holder lamenting the dismissal of human trafficking charges against people accused of exploiting them.

The letter expresses regret that the largest-ever human trafficking case brought by the U.S. government ended without going to trial. It tells Holder the workers had faith in the U.S. justice system. 

“Some of us spent hours upon hours detailing our experience over and over again to federal agents,” the letter said. “Many of us still had the documents needed to prove everything we said was true.” 

Global Horizons, of Los Angeles, was accused of manipulating 600 Thai workers it placed in farms across the United States.

The company’s attorney in Honolulu, Michael Green, last month called the dismissal a “moral victory.” 

Chanchanit Martorell, executive director of the Thai Community Development Center in Los Angeles, said it’s contradictory for prosecutors to tell the center its clients were victims of a severe form of trafficking but that they can’t prove the charges beyond a reasonable doubt.