Dead Men Walking: The Case for DNA Testing

May 12, 1978: It was a grisly scene in Chicago's Ford Heights neighborhood. A white suburban couple was found dead after being kidnaped and shot at point blank range. Over the next few days, police arrested four young black men after receiving an anonymous phone tip.

"The day of my arrest is something that's unforgettable," said Dennis Williams, one of the accused, in a recent interview with Oprah Winfrey. "The officer said, 'Nigger, you gonna fry.'"

Although prosecutors had no real physical evidence, they charged the "Ford Heights Four" with murder. Williams maintained his innocence, but within a year, the suspects were tried and convicted. For the next 18 years, Williams lived on death row, 25 feet away from the electric chair.

"I had never been in the room, but officers had told me when they walked in the room, it was like they could smell death," he said. "I'd jump up sometimes in the middle of the night sweatin'."

Student Detectives

In 1987, he was again sentenced to death after a second trial and a second lawyer failed him. Williams lost all faith in the legal system, but refused to give up. Meanwhile, miles across town at Northwestern University, journalism professor David Protess assigned his students the task of uncovering the truth.

After spending only a month on the investigation, the students found the key piece of evidence at the bottom of a box. They uncovered a street file showing that within one week of the crime, the police knew who the real killers were and had buried it. A few months later, a DNA test exonerated Williams and the other men. The real killers later confessed to the journalism students on tape and were brought to trial.

On June 14, 1996, Williams was finally set free. "I felt good, but I couldn't express it because I had stopped believing in justice," he said. "So this is what's scary about the death penalty. A journalism professor got more justice in this case than anybody in law enforcement had the courage to get."

Today, Williams never leaves home without calling someone so that he has an alibi. "With time, I think there will be a degree of healing, but to what extent, I don't know."

Freed From Death Row

Since 1976, when the death penalty was reinstated, 87 men and women have been taken off death row and freed because they were proven innocent. Racial bias, legal incompetence and DNA testing have all had an impact on these cases.

One of the most famous was Rubin "Hurricane" Carter, depicted in the movie "The Hurricane." In 1985, the former middleweight boxer -- convicted twice of a triple murder in 1966 -- was released from Rahway State Prison after 19 years. A judge ruled that Carter had been denied his civil rights by prosecutors during trials in 1967 and 1976.

Then there's Randall Dale Adams, whose life inspired the documentary, "The Thin Blue Line." The state of Texas sentenced him to death for killing a police officer in 1976. Adams was released in 1989 after DNA testing proved he did not commit the crime -- just 72 hours before his scheduled execution.

It's important to note that the majority of death row prisoners are guilty. But one study suggests that for every six people executed, one is set free on the grounds of newly-discovered evidence of innocence.

Horrible Odds

"How can anyone say these are anything but horrible odds?" said attorney Barry Scheck, DNA evidence expert and co-founder of The Innocence Project, in a recent Associated Press report. "Almost one in six times, we are dead wrong. If you got the wrong results at a hospital one in six times, you'd have no faith in the system. You'd demand the hospital be shut down."

Founded in 1992, The Innocence Project provides pro bono legal assistance to inmates who are challenging their convictions based on DNA testing of evidence.