TURKISH PRESIDENT Recep Tayyip Erdogan promised he would deliver the “naked truth” about Jamal Khashoggi in a speech to parliament Tuesday. For the most part he failed to deliver, appearing less interested in revealing what really happened to the Saudi journalist than in leveraging the murder for political gain. That only sharpens the argument for an impartial international investigation.

Mr. Erdogan flatly contradicted Saudi Arabia’s story that Mr. Khashoggi died accidentally during a rogue operation, saying he was the victim of a “savage murder” that was planned in advance. But Mr. Erdogan only elliptically offered Turkey’s version of events, which has been dribbled out in media leaks over the past two weeks, and he did not detail the evidence to back it up. He made no mention of the audiotape of the murder that Turkish investigators say they have, which they have reportedly played for the CIA.

Mr. Erdogan said Turkey would not be satisfied with blaming the slaying on “a handful of security and intelligence members,” as the Saudis have tried to do, and called for identifying “those responsible — from the highest ranked to the lowest — and . . . bring[ing] them to justice.” But he did not point a finger at Crown Prince Mohammed bin Salman, the de facto Saudi ruler and likely author of the operation — thereby leaving room for the Saudis and their allies in the Trump administration to achieve their main objective, which is shielding the crown prince.

Despite some conflicting statements, President Trump still seems wedded to that goal. In an interview with USA Today on Monday, he again called the Khashoggi murder “a plot gone awry,” echoing Riyadh’s preposterous cover story. Sanctions announced Tuesday by Secretary of State Mike Pompeo, including visa restrictions on 21 Saudi suspects, appeared to be aimed at the scapegoats already rounded up in Riyadh.

The conflicting accounts and the political calculations behind them make clearer than ever the need for an independent inquiry. Mr. Erdogan himself called for such an investigation; he should ask U.N. Secretary General António Guterres to initiate it. That would allow the Turks to turn over the evidence they have, including any audio or videotape, in a way that could sidestep the political calculations that now appear to be deterring full disclosure.

Plenty of questions remain unanswered, including some raised by Mr. Erdogan. How did Mr. Khashoggi die? The Saudis claim he was choked to death after an argument escalated into a “brawl,” while a grisly leaked Turkish version says his fingers were chopped off before he was injected with a drug and dismembered by an autopsy specialist who traveled to Istanbul with a bone saw. The audiotape could settle the question.

Where is Mr. Khashoggi’s body? Mr. Erdogan pointed out that the Saudis are claiming it was handed over to a “local collaborator”; if so, they should identify him. And what about the so-called body double — a Khashoggi look-alike who emerged from the consulate wearing his clothes and a fake beard? If the intention was only to question the journalist, why was he there?

The most important question is who ordered the operation. As we have written before, much of the publicly available evidence points to Mohammed bin Salman. At this point, the burden should be on the Saudis to prove he is not responsible — and in the meantime, the crown prince should be treated as a pariah.