Lingering questions about the murder of journalist Daniel Pearl finally may be getting answered thanks to an extensive investigation by students at Georgetown University.
Pearl was on assignment for the Wall Street Journal in Karachi, Pakistan, when he was kidnapped on Jan. 23, 2002, and beheaded days later at the hands of al Qaeda operatives. In the years since, there have been questions as to who specifically was responsible for Pearl's murder.
The Georgetown students found that 27 different men allegedly were involved in the crime and that 9/11 mastermind Khalid Sheikh Mohammed almost certainly was the masked executor who took Pearl's life.
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The findings of the three-year investigation were published today in an expansive report, titled "The Truth Left Behind: Inside the Kidnapping and Murder of Daniel Pearl." The team of 32 students who worked on the project were led by former Wall Street Journal reporter Asra Nomani and Georgetown University professor Barbara Feinman Todd.
According to the report, only four of the 27 men allegedly involved in the murder have been charged and convicted, and 14 others remain free.
Others are in custody but have yet to be charged in the crime, including the man who once was al Qaeda's second-in-command, Khalid Sheikh Mohammed, who currently is being held at Guantanamo Bay.
"The Pearl Project reveals that justice was not served for Danny," said Nomani in a release.
The students unearthed information revealing that U.S. officials have used a "vein matching" technique to verify that Khalid Sheikh Mohammed was, in fact, the man who beheaded Pearl. Similar to the concept of an iris or retina scan, veins from the hand of the executor seen on the video tape carefully were measured for length and spacing and then compared with images of veins on Mohammed's hand taken while he was in U.S. custody.
The al Qaeda leader had already confessed to the murder, but officials were concerned as to whether the confession was a result of waterboarding and might not be admissible in court. He still has not been charged with Pearl's murder.
The "vein matching" technique is based on sound scientific principles, experts said, but far from a standard procedure in crime labs. The arrangement of veins visible to the naked eye on the back of a hand is in theory unique from person to person, but experts said that its reliability as a forensic identification tool is unproven.
"I have no doubt that this is reliable, but it's admissibility in a courtroom is a whole other story," said Lawrence Kobilinsky, a professor of forensic science at John Jay College in New York.
Kobilinsky had never heard of the technique being used as evidence in a court before, and it easily could be thrown out by a judge. But, he said, the "vein matching" technique still could be useful for law enforcement looking to charge Pearl's killer.
"It would corroborate a confession," Kobilinsky said. "When you put the information together and it fits, then it's stronger."
For their part, the Georgetown students and teachers believe the case is solved and that Pearl himself would be pleased with their efforts.
"It was his clues that we followed, his notes that we studied," Nomani said. "This was his last story, and I think he would be really proud of these students and all of the spirit with which this work was done."
ABC News' Thomas Giusto contributed to this report.