His death has cast a harsh light on the rule of the Saudi Arabia's young crown prince, Mohammed bin Salman, who has eased social restrictions at home while pursuing an unrelenting crackdown on rivals and critics, imprisoning hundreds.
He told the Wall Street Journal: "Well, the prince [Mohammed bin Salman] is running things over there more so at this stage".
Callamard says she didn't need anyone else linked to the crime to conclude there was an "extrajudicial execution" - though she said it's still not known how high the order to kill Khashoggi went.
"The problem with stopping selling arms is that it doesn't have any effect on the ability of these countries to behave in the way that they want to because there are plenty of other sources of arms procurement", he said. The execution was awful.
"We will prove to the world that the two governments (Saudi and Turkish) are cooperating to punish any criminal, any culprit and at the end justice will prevail", Prince Mohammed said.
The Khashoggi case has also embarrassed the Trump administration, which regards the crown prince as one of its closest Arab allies and Saudi Arabia as a cornerstone of a United States strategy to counter Iran.
Is the global response to Khashoggi killing tough enough?
US President Donald Trump waves prior to departing on a trip to Wisconsin from the White House in Washington, October 24, 2018. "We will continue to explore additional measures to hold those accountable", Pompeo said.More news: Sahle-Work Zewde is elected Ethiopia's first Female President
More news: India's Virat Kohli becomes the fastest batsman to reach 10,000 ODI runs
More news: ‘Halloween’ Reboot Slays The Competition At The Box Office
Khashoggi was living in exile in the United States and had planned to move to Istanbul and marry his Turkish fiancée. British Prime Minister Theresa May said its Saudi arms sales were "under review", a stance similar to that expressed by Australia.
"We are determined not to allow a coverup of this murder and to make sure all those responsible - from those who ordered it to those who carried it out - will not be allowed to avoid justice", Erdogan said at a speech in Ankara Wednesday, news agencies reported.
The crown prince's comments at the Future Investment Initiative in Riyadh were his first since the Saudi government admitted Khashoggi was killed within the Saudi consulate in Istanbul, Turkey. But certainly, president Erdogan was not complimentary of what happened.
But Turkish officials, from the start, have said Khashoggi was killed in a premeditated fashion by a team of Saudi operatives who were dispatched to Istanbul from Riyadh, the Saudi capital, and that his body was later dismembered.
In the latest revelation, Turkish media Wednesday published a security camera image showing a vehicle belonging to the Saudi Consulate purportedly scouting a forest in the outskirts of Istanbul before the killing.
Also on Thursday, Human Rights Watch said that Khashoggi's son, Salah, and his family have left Saudi Arabia for the United States after a travel ban on them was lifted. "The incident is not justifiable", he said.
Saudi leaders have denied involvement in Khashoggi's murder, pushing responsibility down the chain of command.
Khashoggi's death has derailed the powerful prince's campaign to project a modern image of the ultraconservative country, instead highlighting the brutal lengths to which some top officials in the government have gone to silence its critics.
Khashoggi, a columnist for The Washington Post, disappeared after he entered the Saudi consulate in Turkey on October 2 to collect a document for his upcoming marriage to a Turkish woman.