If it weren’t true, it would be the punch line to a bad joke: Have you heard the one about the guy who served 27 years for a murder in which the sole eyewitness was legally blind?

Yet it’s true. Right here in Portland, Maine.

And now that Tony Sanborn, 44, is a free man out on bail, the state has some explaining to do.

Thursday’s bail hearing in Cumberland County Unified Criminal Court would have been stunning enough had it ended simply with the bombshell revelation about Hope Cady’s eyesight.

The state’s star witness testified way back in 1992 that she saw Sanborn, then 16, viciously kill Jessica Briggs, also 16, on the Portland waterfront while Cady watched from a distance.

One problem: Cady suffered from a progressive eye disease that rendered her legally blind, meaning her vision likely was too poor to match her story.

But then this happened:

“Were you down at the pier that night?” asked Amy Fairfield, the attorney who has worked doggedly for the past year to get Sanborn a long-overdue fair shake.

“Not that I can recall,” testified Cady, who was a 13-year-old ward of the state at the time and lived mostly on the streets.

“But you’re certain that you did not witness the murder,” said Fairfield.

“Certain,” replied Cady.

And why, asked Assistant Attorney General Donald Macomber in follow-up questioning, did Cady not come forward sooner?

“I was scared,” she said.

Scared of whom?

“Those detectives,” Cady replied.

That would be retired Portland police Detectives James Daniels and Daniel Young, who helped then-Assistant Attorney General Pamela Ames put Sanborn behind bars all those years ago.

The same detectives who, along with Ames, now owe Sanborn, the court and the people of Maine some answers about how they did – or failed to do – the job society expected of them.

To read Fairfield’s 102-page motion to grant Sanborn’s bail – the precursor to her motion to have his conviction thrown out entirely – is to witness a process in which an at-all-costs guilty verdict now appears to have trumped the truth.

It describes how Cady and other witnesses, mostly street kids already known to police, were cajoled, coerced and outright compelled to implicate Sanborn or else they too might find themselves charged with a crime.

Evidence favorable to Sanborn, which by law must be turned over to the defense in its entirety and without delay, was surrendered in dribs and drabs. Or, when it came to Cady’s documented history of vision and hearing problems, it was withheld altogether.

Take, for example, this tidbit involving Gerard Rossi, another witness who claimed Sanborn had confessed to him multiple times. Or did he?

Rossi, older than Sanborn and already on the police radar for allegedly having sex with underage girls, made his claim about Sanborn confessing in an unrecorded interview with Detectives Young and Daniels in March of 1990.

But the day before that, Rossi told a Florida deputy sheriff in a taped interview – over and over and over again – that Sanborn had made no such confession to him.

“He never told me nothing outright,” Rossi told the deputy while the recorder rolled. “Listen, I’m telling you the truth. He never told me.”

And what happened to that tape?

“I put the tape in a box with other case files,” said Daniels in an affidavit submitted to the court last week. “I had never listened to it.”

Nor would the prosecution turn the transcript of the tape over to the defense until February of 1992 – almost two years after the interview took place.

Why the delay?

“It was an oversight and housekeeping issue with case management for which I take complete responsibility,” Daniels said in his affidavit.

Right. Just like Daniels failed to listen to the tape the moment the Florida detective gave it to him because “I did not take it as relevant.”

According to Fairfield, Rossi ultimately fingered Sanborn for one very good reason: In exchange for his testimony against Sanborn, the prosecution team promised, he’d be off the hook when it came to any charges involving sex with the young girls.

The detectives’ response?

Daniels: “Det. Young and I have both made it a personal policy not to make any promises to anyone.”

Young: “I have never made a deal in any criminal case and in fact often tell defendants that only the prosecution can talk to them about a deal.”

Young went on to say he did not recall “the facts about Gerry Rossi or any other witness, however, any issue of threats to a witness are not true and never occurred.”

How convenient. He can’t remember all of the facts involving Rossi, but he hereby swears that any and all allegations of coercion are not true.

The unraveling goes on and on. More than a dozen times in their affidavits, the two detectives use the phrase “I don’t recall” or the equivalent.

But trust them, they now tell us, their investigation was by the book and virtually flawless.

And where is former prosecutor Ames in all of this?

Assistant AG Macomber, who served as her second in the Sanborn trial, told the court last week that Ames, now a private attorney in Waterville, hadn’t had time to prepare an affidavit of her own in time for the hearing.

(When I called Ames’ law office on Friday, the woman who answered the phone told me to “Have a nice day” and hung up.)

So where does this go from here?

Well, Macomber cryptically claimed in court last week that he may have to recuse himself from further proceedings because he has firsthand knowledge that Cady’s recantation is false and he thus may have to so testify as a witness.

But even if she is now lying, Cady’s credibility is shot. Ditto for two other prosecution witnesses whose affidavits were submitted to the court by Fairfield last week – a woman who says she “lied on the stand” and a man who says his statement to police, made under duress, was “99-percent false.”

All of which adds up to one inescapable conclusion: This case stinks to high heaven. And the sooner the court vacates Sanborn’s conviction and offers him a full apology, the better.

Perhaps more astounding than last week’s courtroom drama, after all, was the grace – and utter lack of bitterness – that Sanborn displayed as he wiped away his tears, embraced his family and supporters and traded in his jail jumpsuit for a set of everyday clothes.

In all his time in prison, even as he steadfastly maintained his innocence, not once did Sanborn commit a disciplinary violation.

Rather, as Fairfield told the court, he’s served almost half of his 70-year sentence as a “model prisoner,” tutoring his fellow inmates, counseling those in crisis, even volunteering to train at-risk shelter dogs in need of a second lease on life.

In short, Fairfield told the court, the man convicted of murder has behaved like a “saint.”

Back in 1993, before Sanborn was sentenced, Nicholas Trout, a volunteer at the then-Maine Youth Center, wrote a letter to the court expressing how “shocked and deeply saddened” he was at the guilty verdict.

Trout had met weekly with Sanborn for more than two years. Throughout it all, he wrote, Sanborn “displayed an uncanny optimism that the truth would see him out of jail.”

Now, more than a quarter-century later, the truth is finally emerging.

Anyone can see that.

Bill Nemitz can be contacted at:

[email protected]