John Giuca was accused of being a gang boss who ordered the death of a teen. But as the case slowly falls apart, he may turn out to be just another victim of Brooklyn justice.

In the early hours of Oct. 12, 2003, a handsome 19-year-old college football star named Mark Fisher accompanied a college classmate, Angel DiPietro, to a house party in Ditmas Park, Brooklyn.

Several hours later, a few blocks away from the house, Fisher was found dead — shot five times, lying on top of a blanket.

Suspicion fell quickly on the party’s host, 20-year-old John Giuca. During the sensational trial that followed, prosecutor Anna-Sigga Nicolazzi told the jury that Giuca, whom she described as a Tony Soprano-like gang boss, had armed his loyal “soldier,” co-defendant Antonio Russo, and ordered him to kill Fisher.

Giuca and Russo were both sentenced to 25 years to life.

But now, nine years after the verdict, the case against Giuca appears to be crumbling, possibly adding to a long line of overturned convictions from the era of former District Attorney Charles Hynes.

‘The Ghetto Mafia’

Mark Fisher’s murder dominated front pages as investigators struggled for more than a year to make an arrest. Initial reports of the shooting came in through 911 and cops arrived on the scene within three minutes. They found Fisher’s body at the end of a driveway on Argyle Road; only two shell casings were recovered from the scene.

A canvass of the block revealed that many residents had heard multiple gunshots, and several also heard car doors opening and closing and a car drive away; some saw the car and one reported hearing the sound of voices, including that of a young female.

Cops later got information that Fisher had attended the impromptu party several blocks away at Giuca’s home, where DiPietro was the only person he knew.

All the partygoers lawyered up almost immediately. Cops publicly declared the group uncooperative, and the Fishers offered a $100,000 reward for any information leading to an arrest.

But it wasn’t until Hynes assigned an “elite team” to the case — including his controversial former rackets chief Michael Vecchione and the telegenic Nicolazzi — and convened a special, investigative grand jury that people began to talk.

Albert Cleary, the son of a prominent member of the Brooklyn Republican Party and a friend of Giuca’s, was one of the first to finger him, but only after the DA threatened Cleary about the status of his probation in connection with a brutal assault he committed only months earlier when he kicked a man in the head, rendering him unconscious.

Fisher’s body was found about 50 feet from Cleary’s back door. Months before, under a cloud of suspicion himself, Cleary had submitted a polygraph report to the DA through his lawyer indicating he knew nothing about the crime.

At trial, Cleary, who had attended the party, testified that Giuca had called him in the late morning after the murder, in what was framed as an initial attempt to cover up his knowledge of the crime. Cleary also recounted that Giuca ultimately confessed to him that night, in the presence of Giuca’s then-girlfriend (who had not been at the party).

Cleary said Giuca told them he gave Russo a gun and instructed him to show Fisher “what’s up” after Fisher “disrespected” him by sitting on a table.

Cleary also spoke of Giuca’s status as a “capo” in a local gang, dubbed the Ghetto Mafia, and recounted an alleged conversation prior to the murder between Giuca and “the boss” — in reality, a college student in North Carolina double-majoring in accounting and economics — about the need to “get a body” in order to bolster the gang’s credibility.

Phantom phone calls

But Cleary put the place of death about three blocks from where Fisher was shot, and neither he nor anyone else who testified offered an explanation as to how Fisher ended up on Argyle Road.

The testimony of Giuca’s girlfriend, Lauren Calciano, about this alleged confession also differed markedly from Cleary’s, even though they supposedly heard it together. Calciano said Giuca told them that Russo planned to rob Fisher and asked Giuca for a gun. She even put the time of the “confession” in the afternoon after the murder, while Cleary said Giuca confessed to them at night.

Calciano has since recanted her testimony, claiming she was pressured and threatened by prosecutors to testify against Giuca.

Cleary’s own grand jury testimony also told a different story. It wasn’t Giuca but someone else who had been upset that Fisher sat on the table. And gang involvement? No mention of it.

Perhaps most striking, Cleary told the grand jury that Giuca first called him not in the morning but about 1 p.m. that day — a fact that is confirmed by phone records Nicolazzi introduced into evidence and that the DA publicly touted as the key to cracking the case. Despite this, Nicolazzi elicited the incorrect time from Cleary.

Why? Most probably to harmonize his account with DiPietro’s and remove what were possible credibility issues.

DiPietro testified that at about 6:10 a.m., roughly a half-hour before the murder, the pair left Giuca’s house together and went to sleep at Cleary’s nearby home. Though Fisher’s body would be discovered across the street from where they reportedly slept, both denied hearing anything.

Two friends called DiPietro around 11:30 a.m. looking for Fisher; she told them he had left the party a few hours earlier. DiPietro later claimed that one of the other partygoers, Meredith Denihan, had been the one to tell her that Fisher left Giuca’s house safely, but that turned out to be a lie; the two had not spoken that morning.

Ultimately, DiPietro changed her story, claiming that Giuca had been the one to report that Fisher had left safely, in an 11 a.m. call to Cleary that the prosecution knew never happened.

Ironically, DiPietro was hired as a prosecutor by Hynes in 2012.

Changing stories

In her opening statement, Nicolazzi suggested that the killing of Fisher was gang-related.

But by the end of the trial, she introduced a completely new theory of the crime through the testimony of a drug-addicted jailhouse snitch named John Avitto.

Avitto testified that Giuca had confessed to him in jail, where he said he also overheard Giuca and his father speaking about the murder in the visiting room. This story had Giuca, Russo and a third individual beating Fisher after he refused to hand over $20 he had withdrawn from an ATM. In this version of events, Russo wrestled the gun from Giuca and shot Fisher. Despite the fact that his account contradicted that of every other witness, in her summation Nicolazzi told the jury that Avitto was “truthful,” “honest” and that “everything [he] told you is credible.”

Avitto has also recanted his testimony in a sworn affidavit. He now says he fabricated his entire story with help from newspaper accounts, in order to curry favor with the DA on his criminal charges. As it turns out, medical records show that Giuca’s father, having suffered a series of debilitating strokes, was unable to hold a conversation.

The jury ploy

From the start, Giuca maintained his innocence, saying he fell asleep in his home after the party and had no idea what happened to Fisher. Russo also maintains his innocence.

After Giuca’s conviction, his mother, Doreen Giuliano, began a quest to exonerate her son.

In one of the more bizarre aspects of this case, Giuliano concocted a false identity, Dee Quinn, rented an apartment and wore hotpants to befriend a juror, Jason Allo, who sat on her son’s trial.

Giuliano promised her husband, Frank, that she wouldn’t have sex with Allo, but told The Post in 2012, “Look, husbands are always second when you have kids. So when you say you’d do anything for your kid, you mean it. And if I’m gonna lose Frank over my son, so be it. You can always get another husband. And would I lie if I did [sleep with Allo]? Yeah, most likely, yes, I would lie.”

After months of secretly recorded conversations, Allo admitted he had undisclosed connections to the case, that he recognized some of the witnesses from the neighborhood. He also mistakenly thought Giuca was Jewish and didn’t like Jews. But a judge threw out all of Giuliano’s appeals.

Giuliano didn’t give up. She hired criminal defense attorney Mark Bederow, of Bederow Miller LLP, to reinvestigate the case. Working with Jay Salpeter, an ex-cop-turned-private investigator with a specialty in wrongful convictions, Bederow uncovered what he alleges is compelling evidence of prosecutor misconduct. They also obtained key witness recantations — including those of Giuca’s former girlfriend and the jailhouse snitch.

The Ghetto Mafia, Giuliano said in a TV interview, is just a name Giuca and his friends called themselves as a joke. They weren’t a gang. They weren’t robbing people, and they certainly weren’t killing people.

Bederow declined to comment on the case, citing a pending review by the district attorney’s office. A spokesman for Brooklyn DA Kenneth Thompson declined to comment on the substance of the review or any likely decision.

What really happened on Argyle Road? Despite the reports of a car and voices at the scene of the shooting, the only witness from that block who was called to testify at trial was a 911 caller who said he saw and heard nothing but five gunshots. And so like that, the voices and the car disappeared from the narrative of the crime.

John Giuca could be freed, but what really happened to Mark Fisher — and why — on that tragic autumn morning may never be answered.

End of an error: The Brooklyn cases that have been dismissed

If John Giuca is freed, it will be one of a number of cases — many prosecuted under former Brooklyn DA Charles Hynes — that have been thrown out recently.