More than likely, we’ll never know.

More than likely, we’ll never know.

WASHINGTON — Perhaps Troy Davis is the violent thug who senselessly gunned down an off-duty police officer in a dimly-lit Savannah, Ga. parking lot on Aug. 19, 1989. He was convicted of the crime two years later, after several witnesses confidently pointed their fingers at him as the triggerman who robbed Mark Allen MacPhail of his life.

But there are equally compelling arguments that point to Davis’ innocence, that suggest, instead, he was set up by the actual triggerman and witnesses who lied to protect themselves. That’s the problem with this case: There is reasonable doubt.

The American criminal justice system, fraught with human frailty, isn’t well-equipped to handle such doubts after a man has already been convicted by the proverbial jury of his peers. So Davis is set to die by lethal injection on September 21 unless the Georgia Board of Pardons and Paroles, his last hope, grants him clemency. (The board meets on Sept. 19.)

How did Davis end up on death row with no physical evidence — no gun, no fingerprints, no DNA — to tie him to the crime? How could he be condemned by an investigation that started with the word of a petty hoodlum?

If you’re a fan of TV and paperback police procedurals, you may believe that police work is thorough, that criminal labs are well-funded, that police officers are wise to the manipulations of career cons. They untangle masterful plots and get to the bottom of endless deceits.

Real life is a lot more, well, real. The day after MacPhail was shot, a dodgy character named Sylvester Nathaniel “Red” Coles walked into the Savannah police department, with his lawyer in tow, and reported that Davis had killed the officer.  Never mind that Coles was less than reliable; he had a record for, among other things, weapons offenses. When he offered up Davis, Savannah police — desperate to catch the criminal who had gunned down a fellow officer — had their man.

They rounded up Davis’ known associates; they knocked on doors in the neighborhood; they leaned on possible witnesses. They got what they were looking for — fingers pointing at Davis.

But years later, seven of nine key prosecution witnesses recanted their testimony. Several said they had been pressured by police and feared retaliation if they didn’t give them the story they wanted. Other individuals offered new information that implicated Coles — who had originally fingered Davis.

As troubling as that is, it has not bought Davis a ticket off death row. The criminal justice system simply isn’t good at acknowledging doubts about prior decisions.

In the 1990s, the public became so impatient with what we deemed “frivolous appeals” by death row inmates that Congress passed a law “streamlining” the process, leaving condemned prisoners less time to argue their innocence. That may have helped us quickly extract revenge against our most notorious killers, but it also meant, inescapably, that some innocent parties would be fast-tracked to their graves. That law, indeed, has hindered Davis’ efforts to get off death row.

In 2008, the Georgia Supreme Court, giving short shrift to the new testimony, refused to grant Davis a new trial. In 2009, the U.S. Supreme Court ordered a review of the new evidence, but it set up an impossible standard: Davis had to prove his innocence. Needless to say, he couldn’t.

Davis’ last hope lies with the Georgia Board of Pardons and Paroles. Its members will be under tremendous pressure, but they should worry most about sending the wrong man to his death

Given the difficulty of discerning the truth, they could commute Davis’ sentence to life in prison. Even if he killed MacPhail, he is no threat to public safety in a prison cell.

Who knows? Maybe another culprit will one day give a death-bed confession and Davis could go free. More likely, we’ll never know for sure who killed a young police officer attempting to break up a brawl in a dark parking lot 22 years ago.

And that’s the problem with sending Davis to his death.

Cynthia Tucker