Ahmed Bedier, the head of the Justice for Jamal Campaign, speaks during a memorial for slain journalist Jamal Khashoggi in Washington on Nov. 2. (Michael Robinson Chavez/The Washington Post)

IN THE days after Jamal Khashoggi disappeared inside the Saudi Consulate in Istanbul, the kingdom’s ambassador in Washington, Khalid bin Salman, launched an epic campaign of lies. He told anyone who would listen — from senators to the publisher of The Post — that reports that Mr. Khashoggi had been detained or killed inside the consulate were “absolutely false, and baseless.” He said no one in the regime of his father, King Salman, or his brother, Crown Prince Mohammed bin Salman, knew what had happened to Mr. Khashoggi. “What we do care about is Jamal’s wellbeing and revealing the truth about what has occurred,” one statement by the ambassador said.

A couple of weeks later, as the truth became undeniable — that the regime had sent a hit team to Istanbul to kill Mr. Khashoggi and dismember his body — the ambassador slunk out of Washington for Riyadh. Few expected the return of an envoy with “zero credibility,” as Sen. Bob Corker (R-Tenn.) succinctly put it. Yet on Wednesday, as former president George H.W. Bush was memorialized at Washington National Cathedral, Khalid bin Salman reappeared in town, apparently with the intention of at least temporarily resuming his post. It was a stunningly arrogant act — one that underlined the regime’s defiant lack of repentance about the murder.

The public record establishes definitively that Khalid bin Salman participated in the coverup of the Khashoggi slaying, which the CIA says was almost certainly ordered by his brother. The ambassador also may have played a part in the murder plot itself. Several news organizations, including The Post and the Wall Street Journal, have reported that the ambassador directed Mr. Khashoggi, who lived in Virginia, to visit the consulate in Istanbul to obtain a document he needed for a planned marriage, and assured him he would be safe there. Khalid bin Salman denied the reports. But, as already has been thoroughly established, he has no compunction about lying. And in one of his own statements, he said he had “maintained regular contact” with Mr. Khashoggi “when he was in Washington.”

The need to determine the complicity of Khalid bin Salman and his brother Mohammed bin Salman in the Khashoggi killing is one reason an independent international investigation is still needed. Meanwhile, senators who have instructed the White House to determine Mohammed bin Salman’s responsibility under the Global Magnitsky Act, which provides for sanctions for human rights crimes, ought to demand the same for Khalid bin Salman.

As for resuming his diplomatic duties: Anyone who does not object to the murder of a journalist, the use of a diplomatic facility for such a crime or the wanton lying to cover it up will welcome him back to Washington. He should be shunned by everyone else.