CLEVELAND, Ohio -- The use - and abuse - of undocumented farm workers is prevalent across Ohio and rarely results in criminal charges, activists and prosecutors say.

That's because the secretive people who smuggle workers into the country are difficult to infiltrate, according to Steven Dettelbach, the U.S. attorney for the northern district of Ohio. And so are many of the workers, who fear being deported and distrust police.

"Where they come from," he said in an interview with cleveland.com, "the police are not going to be on the side of a poor or powerless victim."

Dettelbach and his office are prosecuting a case in which more than 40 workers were smuggled into the U.S. from Guatemala and forced to work on chicken farms near Marion, 120 miles southwest of Cleveland.

In this case, agents were able to talk to several of the workers who spoke of their handlers using threats to hold them as captives in small mobile homes and busing them daily to the farms.

That information from the workers allowed federal agents and local police to make inroads into the trafficking ring. They conducted surveillance, pulled over vans that had workers in them and talked by phone with the workers' family members in Guatemala.

Dettelbach said that kind of access to victims is not common. Generally, he said, undocumented workers have a deep-seated distrust of law enforcement, because police in their native countries often abuse their power.

And some police and prosecutors in the United States have prosecuted the workers for being undocumented rather than pursuing the people who have abused them.

Baldemer Velasquez, head of the Toledo-based Farm Labor Organizing Committee said he suspects some of the farms know they are using undocumented workers, but look the other way out of a desire for cheap labor.

Dettelbach said more public education about labor trafficking is needed.

Education efforts have succeeded in bringing attention to sex trafficking, another form of forced labor, according to officials with the Salvation Army of Central Ohio.

The organization has provided aid to human trafficking victims in several cases. Of the 590 human trafficking cases it has worked since July 2008, 86 percent pertained to sex crimes and 14 percent were for forced labor, according to its statistics.

Michelle Hannan, director of professional and community services for the Columbus-based organization, said she does not get as many calls for labor trafficking as she does for forced prostitution.

Dettelbach's office was recently chosen as a participant in a U.S. Justice Department program to investigate and prosecute more labor and sex trafficking cases. Under the program, announced in December, prosecutors will work with local federal investigators and report their progress to coordinators in Washington, D.C.

Dettelbach said farms that work with labor traffickers unfairly benefit, since the low cost of workers results in more profits.

"Obviously, though, many, many farmers and agricultural operations don't do this," he said. "And it's important to say that, and they're the ones that are also victimized by the few who do this because it's unfair in terms of competition for one to be able to use slave labor and the other to be playing by the rules."

Read more of cleveland.com's package on labor trafficking in Ohio:

* Part 1: Read about a human-trafficking ring run out of a mobile-home park in central Ohio, and the methods the federal government used to break it up.

* Part 3: Read about Trillium Farms and the steps it says it took following a federal investigation into its laborers.

* Part 4: U.S. Sen. Rob Portman on Thursday plans to unveil an investigation done by a committee he chairs into placing unaccompanied minors caught crossing the U.S.-Mexico border.