Four men including a UK national who were imprisoned for killing Wall Street Journal reporter Daniel Pearl were not present during his beheading but were convicted of murder because Pakistani authorities knowingly relied on perjured testimony and ignored other leads, a report has concluded.
The results of the Pearl Project, an investigation carried out by a team of US journalists and students and spanning more than three years, raise troubling questions about Pakistan's dysfunctional criminal justice system and underscore the limits US officials face in relying on Pakistani authorities.
The four men convicted in the killing did help kidnap the American journalist, according to the investigation. But it says forensic evidence known as "vein-matching" bolsters the confession of al-Qaida third-in-command Khalid Sheikh Mohammed, the professed mastermind of the September 11 attacks on the US, to having killed Mr Pearl.
The report says at least 14 of 27 people involved in abducting and murdering Mr Pearl in 2002 are thought to remain free. And the four who have been convicted could be released if their appeal is ever heard because of false and contradictory evidence used in their trial.
Mr Pearl, 38, was abducted from Karachi on January 23, 2002, while researching a story on Islamist militancy after the September 11 attacks.
On February 21, 2002, a shocking video of his killing was delivered to US officials in Pakistan. His remains were found in a shallow grave on Karachi's outskirts three months later.
Within months of his disappearance, Ahmed Omar Saeed Sheikh, a Londoner of Pakistani heritage, and three accomplices were caught, charged, and convicted of murder and kidnapping. Sheikh, called the kidnapping's mastermind, was sentenced to death in July 2002.
The three others were given life terms, which in Pakistan usually means 25 years.
Since then, the men's appeals have gone nowhere in the courts, despite dozens of hearings. Both the defence and the prosecution blame each other for stalling tactics, and there is constant speculation that Sheikh is being protected, possibly by Pakistani intelligence agencies.
Defence attorney Rai Basheer said the prosecution knows it would lose on appeal and is delaying the process, but prosecutor Raja Qureshi dismissed those claims.
"I challenge the defence to come and attend the case properly and consistently, and they will themselves know whose case is weak," he said.
The Pearl Project's findings appear to strengthen the defence's hand. For instance, it finds significant discrepancies between Pakistani police reports and later court testimonies, including that of a taxi driver whose account was considered crucial to the conviction.
Authorities apparently cajoled the driver to change his earlier story and, while testifying, place Sheikh with Mr Pearl near the restaurant where the journalist was picked up by his abductors, the report says. But Sheikh is believed to have left Karachi before other men he had recruited carried out the kidnapping.
At the same time they were building their case against Sheikh and the three others, investigators did not pursue leads provided by another suspect in custody. That man, Fazal Karim, allegedly was one of the guards holding Mr Pearl hostage and was there during his killing. Karim also led investigators to Mr Pearl's grave.
But his account differed from the taxi driver's, threatening the prosecution's case against the four on trial. US officials pushed the Pakistanis to restart the trial to include all the evidence, but the prosecutor argued that doing so would give the defence a huge advantage, so Karim's account didn't make it to court, and he was later set free.