Washington (CNN) -- To many Americans, putting Jared Lee Loughner in a mental hospital instead of a prison hardly sounds like justice.
The question is not a new one: Where is the line between insanity and accountability?
The courts have spoken in this case. The gunman who nearly assassinated Arizona Rep. Gabrielle Giffords and killed six people outside a suburban grocery store has been declared mentally unfit to stand trial. The ruling has reopened an old debate over what to do with the criminally insane.
The makers of a little-known documentary would like to shed some light on the subject, from behind the walls of one of the nation's best-known mental institutions. The film, "Saint Elizabeths Hospital: Voices from Within," takes its viewers into the world of the "not guilty by reason of insanity."
"It's unfiltered. It's told through them. It's told through their eyes," said Ellie Walton, one of the movie's co-directors.
This is no reality TV show filmed inside the county jailhouse. This movie was made inside Saint Elizabeths Hospital in Washington. That's no small task. The hospital does not allow cameras inside its facilities. One of its most infamous patients has been John Hinckley, the man who tried to assassinate President Ronald Reagan.
Walton and her co-director, Joy Haynes, obtained permission from Saint Elizabeths to put cameras into the hands of a select few patients.
"This film humanizes them, and we feel connected to them, and so the stereotypes of them disappear," Haynes said.
One of the patients featured in the documentary is Lewis Ecker, who raped and strangled to death a U.S. senator's aide more than four decades ago.
"That's like 43 years that this was my home. This was where I lived. Believe me ... lived and died," Ecker says in the film.
Other patients are shown living somewhat normal lives. They wear clothes, not prison stripes. Their home is a hospital, not a penitentiary. Patient rooms look like dorm rooms. One of the committed men featured in the documentary is seen roaming the fenced-in grounds in solitude.
But the faces of the patients reveal another side of life here. They know they cannot leave until they are well. The prison is in their minds.
"The impression of the public is that this is a 'get out of jail free' card ... that criminals can use if they just act a little bit dodgy," said George Washington University law professor Jonathan Turley. But the fact is, the insanity defense is considered a long shot in the U.S. justice system. It is attempted in less than 1% of felony cases and is successful only a tiny fraction of the time. Part of the reason, says Turley, is Hinckley.
"The great irony is that this was in some ways the poster boy for the insanity defense. He was insane," Turley said. "But people wanted revenge. They wanted him held accountable. They were angry. And they couldn't take out that anger on John Hinckley. So instead they took it out on the criminal code."
After Hinckley was found not guilty by reason of insanity, Congress tightened the federal rules for insanity defenses. Thirty states did the same.
"You have to be virtually chewing the carpet in the courtroom to qualify for the insanity defense," Turley said.
For the criminally insane, getting out of a mental institution is just as difficult.
"My lawyer said, 'You'll be here for 90 days' observation.' And that 90 days turned into 23 years," said Calvin Neal, one of the patients featured in the documentary.
All of the patients in the Saint Elizabeths film believe someday they will be released.
"I'm sure that I can get my life together. I can go out and be responsible. And be a citizen once again in this community. I know I can do this," said Ronald Embry, another patient in the movie.
Many of them have said that for years. At best, this may be the road ahead for Jared Lee Loughner. The road is far from free.