The public defender had a dilemma. She needed a DNA test, hoping it would exonerate her client. But her office couldn’t afford to pay for the test, nor could her client pay out of pocket.

The prosecutor would not likely have the DNA tested, fearing that a finding that it didn’t match the defendant would spike the state’s case.

So the defense attorney had an idea: Move to exclude the DNA evidence from the case, thus perhaps fooling the prosecution into believing the defense was worried the DNA might match the defendant. The prosecutor then might spring for the test, and, of course, would have to share any results with the defense.

This kind of psychological gamesmanship is all in a day’s work for the over-burdened public defenders featured in “Gideon’s Army,” a new documentary selected to participate in the prestigious Sundance Film Festival for 2013. The film’s action takes place in Georgia, a state with a long-standing tough-on-crime, show-no-mercy mentality in its criminal justice system.

The filmmaker is Dawn Porter, working under the banner of her own production company, Trilogy Films. This is her foray into producing and directing a documentary. Porter, a lawyer by training, worked as a litigator at the D.C. office of BakerHostetler before joining the in-house legal department of the ABC television network in New York, eventually landing in the news division. There, working as part of the network’s Standards and Practices team, Porter spent many hours reviewing scripts and raw video of ABC News investigative pieces.

“It was really interesting to me how you could read the script and it would seem very fair, and then watch the video and see how camera angles and other visual techniques were used to push the viewer in a certain direction,” Porter said.

Porter describes “Gideon’s Army” as her attempt to shed light on a criminal justice system in need of reform. When she first met some of the public defenders highlighted in the film, she was struck by their commitment to their work in the face of long odds.

“I was so moved by these young people,” she said. “So many lawyers are just going through the motions. These lawyers are living their passion.”

Though the film is set in Georgia, Porter said the issues faced by the lawyers, such as the lack of sufficient funding for investigations and evidence testing, are universal. Even where public defenders and prosecutors make the same salaries, prosecutors have the resources of police and state crime labs to work for free, while defenders have no such help, she notes.

“There is no jurisdiction in American where the resources are the same,” Porter said. “Prosecutors will tell you they have the same caseloads as defenders, for example. But the difference is, it’s the prosecutors who decide whether a case gets pursued. The defenders have to take every client.”

Media Salad’s senior researcher, Meg Tebo, is a lawyer, longtime journalist and author of Shakespeare for Lawyers — A Practical Guide to Quoting the Bard (ABA Press 2010).