A bombshell documentary has revealed how six men who were wrongfully convicted of murder were eventually exonerated.
The injustice first came to light in 2002 when veteran Bronx homicide detective Bobby Addolorato told NBC Investigative Journalist Dan Slepian there was one murder case that had haunted him for more than a decade.
Bouncer Markus Peterson had been shot dead at the Palladium nightclub in Manhattan on Thanksgiving eve in 1990, with another wounded. It was Latin Night at the club with more than 1,000 people attending.
Addolorato claimed the two men convicted of the crime and locked up at New Yorks Sing Sing Correctional Facility, David Lemus and Olmedo Hidalgo, were in fact innocent - and that he knew who the real shooter was.
It really really ate at him and that is when I said lets make it our story. Let me follow you as we reinvestigate this, Slepian said.
This moment became the springboard for a two-decade investigation that went on to expose a further four wrongful conviction cases at the same prison. In total, six men spent half their lives behind bars for crimes they did not commit.
The extraordinary tale is now being told in full in a new four-part documentary series called The Sing Sing Chronicles, which will air this weekend.
In an exclusive clip shared with DailyMail.com, viewers can see the very moment Addolorato is heard telling a shocked Slepian about the case that haunts him.
Bronx homicide detective Bobby Addolorato (pictured) seated with NBC Investigative Journalist Dan Slepian in a restaurant telling him the one murder case that haunted him for more than a decade
NBC Investigative Journalist Dan Slepian is pictured interviewing a handcuffed David Lemus (left) and Olmedo Hidalgo (right) at Sing Sing in 2002
A new four-part documentary series called The Sing Sing Chronicles will air this weekend. The picture shows an NYPD officer covering a homicide Slepian was nearby trailing the detective
Its going to haunt you, without a doubt. Its going to haunt you until there is closure. And even after there is closure, its still going to haunt you, Addolorato said to Slepian in the clip.
Lemus and Hidalgo had been locked up for over a decade by the time Slepian found out about the case.
He had originally been trailing the detective for a piece about how homicide cops solve murders, and claimed he never imagined where it would lead.
It was hard for me to wrap my mind around with if they were innocent why were they there, he added.
Slepian went to Sing Sing to meet with Lemus and Hidalgo in 2002, where the two men were cuffed and emotional as they spoke about their incarceration.
Lemus had been incarcerated for 11 years and 7 months at that point, and Hidalgo 10 years and 9 months.
No one wants to live in this cage like I am. It is harder to accept being in here when you know you didnt do anything, Lemus said through tears at the time.
Recalling the moment the guilty verdict had been read in court, Hidalgo broke down and said in Spanish that his life had been crushed.
From then on, the detective, with the help of his partner John Schwartz, the journalist and others, pushed to get the case reopened.
Eventually the pair were exonerated in 2005 after nearly 15 years in prison. Lemus was retried in 2007 but acquitted.
Lemus told NBC News he largely credited his release to the two detectives who never gave up.
Speaking of Slepian, he said: He was young, eager and green, but he was also hungry. So I was willing to take my chance with him, because I had nobody else to take a chance with.
Detective Addolorato remarked that seeing them released was the highlight of his career.
Paramedics arrive to transport the wounded after the shooting at the Palladium nightclub
NBC Investigative Journalist Dan Slepian shaking hands with veteran Bronx homicide detective Bobby Addolorato in 2002. Addoloratos partner John Schwartz is pictured right
Bronx Homicide Detective Bobby Addolorato featured during the documentary
The mugshot of David Lemus and Olmedo Hidalgo who were incarcerated for nearly 15 years for a crime they did not commit at the Palladium nightclub November 1990
It was during his visit to the prison that Slepian first met Jon-Adrian JJ Velasquez, who was in the cell next door to Lemus.
Velazquez had been convicted aged 22 for the 1998 murder of a retired NYPD officer and was serving a 25 year sentence.
His mother, who was visiting the jail, approached Slepian and told him her son was innocent and asked if he could help him too.
When he began investigating, Slepian uncovered new information but told DailyMail.com it took an army of people to achieve his freedom.
The docuseries focuses on Velazquez agonizing journey and the special bond the pair went on to form.
In 2012, Velazquez was finally granted clemency and released on parole in 2021. But it was not until October of this year that he was exonerated after his wrongful arrest nearly 27 years ago.
New York State Supreme Court Judge Abraham Clott vacated his conviction after the Manhattan DAs office reviewed his case.
While fighting for his own freedom, Velazquez introduced Slepian to other men he believed were also innocent in unrelated homicide cases.
These men were Eric Glisson, Johnny Hincapie and Richard Rosario, who were also later exonerated.
David Lemus was exonerated in 2005 after nearly 15 years in prison. He was retried in 2007 but acquitted
Dan Slepian speaking during the 4-part docuseries about his 20-year investigation
Today, Velazquez is working as a director of the Frederick Douglass Project for Justice and leads the organizations National Prison Visitation Program.
He is a vocal advocate for legal reform and a champion for those who have been wrongfully convicted.
Slepian was recognized as a Pulitzer Prize finalist and has a podcast Letters from Sing Sing for NBC News Studios.
His 1,000 hours of original footage from 2002 to present day is featured in the four-part episodes showing the gritty streets of New York, the stalwart detectives, the back logs of case documents spanning decades, and prison interviews.
Slepian is pictured speaking to Jon-Adrian JJ Velazquez in 2007 years after he was wrongfully convicted of the murder of a retired NYPD detective
Dan Slepian visiting Velazquez at Sing Sing Correctional Facility in 2017
Slepian and Velazquez attend the screening of Sing Sing on November 15 in Manhattan
Slepian told DailyMail.com how enormously grateful he was that the series is airing this weekend.
I discovered the complexities of our justice system, the power of human resilience and the deep impact of wrongful conviction on individuals, communities and families, he said.
He explained that Sing Sing Chronicles is more than just a docuseries and instead a call to action for empathy, awareness and change.
The series not only sheds light on the flaws within the system but also inspires people to see the humanity in those whose voices are often too silenced, he added.
The four episode Sing Sing Chronicles series, produced by NBC News studios, will air on Saturday and Sunday at 9pm.