ISLAMABAD, Pakistan — The man accused of beheading U.S. journalist Daniel Pearl is set to walk free after Pakistan's Supreme Court ordered his release Thursday.

The Pearl family was “in complete shock” after hearing of the decision, according to a statement from their lawyer Faisal Siddiqi, who called the ruling “a complete travesty of justice.”

Pakistan’s Supreme Court ordered the release Jan. 28 of an Islamist convicted of beheading U.S. journalist Daniel Pearl,leaving his family in “complete shock." (Reuters)

Ahmed Omar Saeed Sheikh was the main suspect in the 2002 kidnapping and murder of Pearl, a Wall Street Journal reporter covering militants in Pakistan in the aftermath of the 9/11 attacks. Saeed, a British-born Pakistani who was implicated in other kidnappings, was sentenced to death for Pearl’s murder and kidnapping, but his case was reopened because of claims of lack of evidence.

Saeed’s murder conviction and sentence were overturned by a provincial court last year, while the kidnapping charge was downgraded. The Pearl family quickly appealed, but that was ultimately dismissed Thursday by Pakistan’s Supreme Court.

The court did not provide any justification behind its ruling. The complete reasons will “be recorded later,” the court said.

Thursday evening, Secretary of State Antony Blinken called the court’s decision “an affront to terrorism victims everywhere, including in Pakistan.” In a statement he said that Saeed remains in custody and that the United States expects Pakistani authorities to “expeditiously review its legal options to ensure justice is served.”

Blinken also noted that Saeed “was indicted in the United States in 2002 for hostage-taking and conspiracy to commit hostage-taking, resulting in the murder of Pearl,” and that the United States is prepared to prosecute Saeed.

“This is an infuriating and unjust decision,” said the Wall Street Journal’s editor in chief, Matt Murray. “We’ll continue to support efforts to hold to account those responsible for the brutal murder of Danny.”

The Justice Department had issued a statement in December from acting attorney general Jeffrey A. Rosen, who called last year’s ruling “an affront to terrorism victims everywhere.” He said that Pakistani authorities were trying to keep Saeed in custody while appeals against the ruling would continue.

“While we remain grateful for the Pakistani government’s opposition to these acquittals on appeal, in light of the Supreme Court’s decision, the Department of Justice reiterates that the United States stands ready to take custody of Sheikh to stand trial here on the pending charges against him,” Rosen said in a statement after the ruling Thursday. “He must not be permitted to evade justice for his charged role in Daniel Pearl’s abduction and murder.”

But following the decision from Pakistan’s highest court Thursday, there are few legal avenues open to the Pearl family. Lawyers representing the Pearl family may petition for a review of Thursday’s ruling, but it’s rare for such reviews to be accepted, according to Abdul Latif Afridi, the president of Pakistan’s Supreme Court Bar Association.

The lawyer representing Saeed said: “Today’s order by the Supreme Court shows that the courts are independent, and they don’t come under any pressure. I am satisfied with the court’s order.” The lawyer, Mahmood Sheikh, said he expects his client to be released immediately.

Pakistani authorities have prevented Saeed from being released in the past, and Pakistani legal experts say it’s possible that another charge could be brought against him to keep him behind bars.

Pearl was told he was meeting with a radical cleric when instead he was kidnapped, held for days and beheaded. When Saeed was convicted months later, he was sentenced for planning Pearl’s kidnapping and murder.

But a 2011 investigation by the Center for Public Integrity’s Pearl Project found that Khalid Sheikh Mohammed, the self-proclaimed mastermind of the 9/11 attacks, killed Pearl. Mohammed was captured in Pakistan in 2003 and is being held at the U.S. military prison at Guantánamo Bay, Cuba. He is not charged in the journalist’s killing.

Pakistan was under immense pressure in 2002 to find the people responsible for Pearl’s killing. At the time of Saeed’s conviction, defense attorneys raised questions about the weight of evidence against him.

Haq Nawaz Khan in Peshawar, Pakistan, and Ellen Nakashima in Washington contributed to this report.