But a 2011 report, based on investigative work by students and faculty at the journalism program of Georgetown University and the International Consortium of Investigative Journalists, cast doubt on the four men’s convictions. It found that Mr. Sheikh and the three other men had been involved in the plot to abduct Mr. Pearl but were not responsible for his murder.
American officials have said that they believed Khalid Shaikh Mohammed, the accused mastermind of the attacks of Sept. 11, 2001, had personally carried out Mr. Pearl’s murder.
While the Pakistani authorities arrested and identified several people in the abduction and killing, their court cases saw acquittals or long delays. At least two people allegedly involved in the murder plot were killed in police shootouts.
Amjad Hussain Farooqi, a close associate of Mr. Sheikh, was fatally shot by the police in 2004. Mr. Farooqi was believed to have picked up Mr. Pearl on the night of the abduction and driven him to a place in Karachi where he was held and killed.
In 2014, Mohammad Hashim Qadeer, another main suspect in the murder, was acquitted by a court in Hyderabad for lack of evidence.
Mr. Sheikh, a British citizen who was trained in camps in Pakistan and Afghanistan, belonged to the militant group Jaish-e-Muhammad at the time of his 2002 arrest. Pakistani investigators said Mr. Sheikh lured Mr. Pearl by offering him an interview with an Islamic cleric who had ties to Richard C. Reid, the so-called shoe bomber, who was accused of trying to blow up a trans-Atlantic flight in December 2001 with explosives in his sneakers.
Mr. Sheikh has made headlines from his cell over the years. In 2008, soon after Pakistani militants carried out terrorist attacks in Mumbai, Mr. Sheikh managed to place a call to Pakistan’s president at the time, Asif Ali Zardari, pretending to be the Indian foreign minister and warning of an attack by India. In 2016, the Pakistani military announced that it had foiled a plan to free Mr. Sheikh from prison.