A demonstrator holds a poster with a picture of Saudi journalist Jamal Khashoggi outside the Saudi Consulate in Istanbul on Oct. 25. (Osman Orsal/Reuters)

THE NEW account of Jamal Khashoggi’s death offered by Saudi Arabia on Thursday was shocking in its audacity. Having previously acknowledged that the journalist was the victim of premeditated murder, authorities in Riyadh reverted to an earlier, discredited tale: that Mr. Khashoggi was killed spontaneously inside the Saudi Consulate in Istanbul by a team sent to return him to Saudi Arabia. While reporting that 11 suspects had been indicted and that the death penalty would be sought for five of them, a Riyadh public prosecutor excused not just Crown Prince Mohammed bin Salman — the chief suspect in the murder — but also two of his top aides, who the prosecutor said ordered or advised the capture operation but did not approve Mr. Khashoggi’s killing.

By offering up this incredible account, the Saudi regime is baldly defying all those, including leading members of Congress, who called for full disclosure and accountability. Yet the Trump administration appears ready to accept its stonewalling. On Thursday, it announced sanctions against 17 people implicated by the Saudis — leaving untouched both the crown prince and top intelligence officials in Riyadh.

Accepting the Saudi story means ignoring a number of well-established facts. An audio recording of Mr. Khashoggi’s last moments, which Turkish officials shared with CIA Director Gina Haspel, indicates he was attacked and strangled immediately after entering the consulate. The Saudi version claims he died only after a quarrel and a struggle that prompted the head of the “negotiation team” to decide to murder him by injecting him with drugs.

The Saudi account says the operation was ordered by the then-deputy chief of intelligence, Ahmed al-Assiri, and advised by Saud al-Qahtani, a court propagandist. Both are close to Mohammed bin Salman. The two aides, so Riyadh’s story goes, were not complicit in the decision to kill Mr. Khashoggi and were fooled by their team’s claim that the journalist had left the consulate alive. That doesn’t explain a portion of the audio recording reported by the New York Times, in which Maher Mutreb, a close associate of the crown prince, instructs an official by phone to “tell your boss” that the mission was accomplished. As the Times reported, U.S. intelligence officials believe the “boss” is “almost certainly Prince Mohammed.”

Other contradictions and improbabilities abound. It’s known that a forensic expert who specializes in autopsies was on the Saudi team; the Turks said he arrived with a bone saw for dismembering Mr. Khashoggi’s body. Yet the Saudis would have the world believe that the specialist was recruited only to clean up any evidence of an abduction, and that officials in Riyadh didn’t know about him.

This all-too-transparent tissue of lies only underlines the need for a genuinely independent international investigation led by the United Nations, as Turkey’s foreign minister called for this week. Instead, the Trump administration is abetting the Saudi coverup; the new sanctions do not even cover Mr. Assiri, the official who Riyadh says ordered the Khashoggi mission.

Congress should not allow this travesty to continue. It should suspend all military sales and cooperation with Saudi Arabia until a credible international investigation of the Khashoggi killing is completed. The Saudi cover story is just one more instance of Mohammed bin Salman’s arrogant and reckless behavior. The true murderers of Jamal Khashoggi must be named and punished.