A man who was "wrongly" convicted of murder has died in agony and his story is now the subject of a shocking new documentary.

In 1989, China saw the Tiananmen Square protests, the United Kingdom witnessed ninety-six people die in the Hillsborough football disaster, The Cold War ended with the fall of the Berlin Wall, and Nintendo released the Game Boy.

Also in 1989, Carlos DeLuna was convicted of killing petrol station clerk Wanda Lopez, who was stabbed to death in Corpus Christi, Texas, in 1983. Right until his death, he maintained his innocence and insisted the crime was committed by a different Carlos (Carlos Hernandez) but he was executed via lethal injection aged twenty-seven.

Youtube: The Phantom Official Trailer

Even though it has been decades since his execution, there has been mounting evidence indicating the DeLuna was, in fact, innocent.

The evidence was unearthed notably by a 2012 Columbia Human Rights Law Review investigation and the documentary, The Phantom, explores his tragic story and the heinous injustice and misuse of the death penalty in modern America.

The documentary was written and directed by Patrick Forbes, an eclectic filmmaker with previous work in WikiLeaks and heart attacks, but has never strayed into the world of capital punishment. Forbe's curiosity in the story of Carlos DeLuna was sparked by a Guardian article from 2012, which reported on the discovery that the state of Texas had wrongfully sent a man to his death.

The article was based on an exceptional piece of sleuthing by a Columbia law professor, James Liebman, and his students who had set out to prove something that advocates of capital punishment vehemently deny – that mistakes are made and innocent prisoners die. The resulting book, The Wrong Carlos, provides a forensic deconstruction of a judicial screw-up of astronomical proportions.

Speaking to The Guardian, Forbes said: "At the end of the film I was angrier by far than when I started it. Everything in the Carlos DeLuna case that could go wrong did go wrong - there was no proper disclosure, the defense was completely underfunded, the appeal was rushed through.

"Not only was he killed an innocent man, the lethal injections didn't work and he died in agony."

As well as sharing the name Carlos, DeLuna said the real killer, Carlos Hernandez, happened to look remarkably similar to him. It was revealed that Hernandez had a history of carrying out similar crimes, including violently assaulting a woman with the same type of lock-blade buck knife that was used to murder Wanda Lopez.

However, in court, prosecutors said Carlos Hernandez was a figment of DeLuna's imagination, or 'the phantom.'

Forbes hopes his documentary will convince anyone that there is no place for the death penalty in civilized society: "Initially, everybody believed one truth: Carlos DeLuna was guilty."

He had a criminal record, he was found hiding under a truck close to the murder scene, and he concocted this ridiculous defense that the murderer wasn't him but another guy called Carlos. Yeah, right."

He then added: "His story shows that capital punishment has no place in a civilized society. If a mistake of this gravity can happen, there is no justification for the death penalty."

You can now watch The Phantom on any streaming service or here.