The wrong Carlos

Carlos DeLuna was arrested, aged 20, on 4 February 1983 for the brutal murder of a young woman, Wanda Lopez. She had been stabbed once through the left breast with an 8in lock-blade buck knife which had cut an artery causing her to bleed to death. From the moment of his arrest until the day of his death by lethal injection six years later, DeLuna consistently protested he was innocent. He went further – he said that though he hadn't committed the murder, he knew who had. He even named the culprit: a notoriously violent criminal called Carlos Hernandez.
 Four years after DeLuna was executed,Professor James Liebman decided to look into the DeLuna case as part of a project he was undertaking into the fallibility of the death penalty. He asked a private investigator to spend one day – just one day – looking for signs of the elusive Carlos Hernandez. By the end of that single day the investigator had uncovered evidence that had eluded scores of Texan police officers, prosecutors, defense lawyers and judges over the six years between DeLuna's arrest and execution. Carlos Hernandez did indeed exist.
Over the years he was arrested 39 times, 13 of them for carrying a knife, and spent his entire adult life on parole. Yet he was almost never put in prison for his crimes – a disparity that Liebman believes was because he was used as a police informant.
 "Its hard to understand what happened without that piece of the puzzle," Liebman says.
 In October 1989, just two months before DeLuna was executed, Hernandez was setenced to 10 years' imprisonment for attempting to kill with a knife another woman called Dina Ybanez. Even then, no one thought to alert the courts or Texas state as it prepared to put DeLuna to death.
 Carlos Hernandez died of natural causes in a Texas prison in May 1999, having been jailed for assaulting a neighbour with a 9in knife.
 Carlos DeLuna commented on his own ending in a television interview a couple of years before his execution. "Maybe one day the truth will come out," he said from behind reinforced glass. "I'm hoping it will. If I end up getting executed for this, I don't think it's right."