ISTANBUL — Turkish crime scene investigators dressed in coveralls and gloves entered the Saudi Consulate in Istanbul on Monday, nearly two weeks after the disappearance and alleged slaying of Saudi writer Jamal Khashoggi there.
Police officers carrying files and equipment walked through the heavy metal doors of the consulate after sunset, carrying out an extraordinary search of a diplomatic post that is otherwise considered foreign soil under international law as worldwide concern grows for the missing Washington Post columnist.
The search represents new cooperation between Turkey, which says it fears Khashoggi was killed and dismembered there, and Saudi Arabia, which maintains the allegations it faces are "baseless" despite being unable to explain what happened to Khashoggi.
However, questions remained over how much evidence the investigators could turn up at a consulate where a cleaning crew entered hours before their arrival.
Meanwhile, President Donald Trump suggested without offering evidence that "rogue killers" may have slain Khashoggi, stepping further back from his pledge that Saudi Arabia would face "severe punishment" if it is found to be responsible for the columnist's yet-to-be-determined fate.
The Turkish team included a prosecutor, a deputy prosecutor, anti-terror police and forensic experts, the state-run Anadolu news agency reported. Certain areas of the consulate were to remain off-limits, although officials would be able to inspect surveillance cameras within the post, Turkish media reported.
Turkish officials have wanted to search the consulate for days. Permission for that apparently came after a late Sunday night call between Saudi King Salman and Turkish President Recep Tayyip Erdogan. In statements after the call, both praised the creation of a joint Saudi-Turkish probe about Khashoggi.
The Saudi acceptance came after the kingdom on Sunday threatened retaliation for any sanctions it could face over Khashoggi. The statement did not elaborate, but a Saudi-owned satellite channel later suggested the world's largest oil exporter could wield that production as a weapon against America.
U.S. lawmakers also have threatened tough punitive action against the Saudis if found responsible for Khashoggi's disappearance. Germany, France and Britain also jointly called for a "credible investigation."
What evidence Turkish officials could gather at the consulate remained unknown. Saudi officials have been in and out of the building since Khashoggi's disappearance Oct. 2 without being stopped. Under the Vienna Convention, diplomatic posts are technically foreign soil that must be protected and respected by host countries.
Earlier Monday, a cleaning crew with mops, trash bags and what appeared to be bottles of bleach walked in past waiting journalists.
Forensics tests like spraying luminol, a chemical mixture, can expose blood left behind, said Mechthild Prinz, an associate professor at the John Jay College of Criminal Justice who previously worked at the New York City's Office of the Chief Medical Examiner.
"It depends on how well they cleaned it up," Prinz told The Associated Press. "Obviously, you don't want anybody to have a chance to clean it up, but very often people do miss blood."
Told that a cleaning crew walked into the consulate before the team arrived, she said: "You saw that? Wow. That's going to be a problem."
Trump tweeted Monday that he had spoken with the Saudi king, "who denies any knowledge" of what happened to Khashoggi.
"He said that they are working closely with Turkey to find answer," Trump wrote. "I am immediately sending our Secretary of State (Mike Pompeo) to meet with King!" Pompeo left Washington soon after.
Trump also seemed to offer another theory for a crime allegedly carried out at the Saudi diplomatic post.
"it sounded to me like maybe these could have been rogue killers. I mean, who knows?" Trump told journalists. "We're going to try getting to the bottom of it very soon, but (King Salman's) was a flat denial."
Khashoggi has written extensively for the Post about Saudi Arabia, criticizing its war in Yemen, its recent diplomatic spat with Canada and its arrest of women's rights activists after the lifting of a driving ban for women. Those policies are all seen as initiatives of Crown Prince Mohammed bin Salman, the son of King Salman, who is next in line to the throne.
Prince Mohammed has aggressively pitched the kingdom as a destination for foreign investment. But Khashoggi's disappearance has led several business leaders and media outlets to back out of the upcoming investment conference in Riyadh, called the Future Investment Initiative.
They include the CEO of Uber, a company in which Saudi Arabia has invested billions of dollars; billionaire Richard Branson; JPMorgan Chase & Co. Chief Executive Jamie Dimon; and Ford Motor Co. Executive Chairman Bill Ford.
News that the CEO of Uber, Dara Khosrowshahi, would pull out of the conference drew angry responses across the region. The foreign minister of the neighboring island kingdom of Bahrain, Khalid bin Ahmed Al Khalifa, tweeted Sunday night that there should be a boycott of the ride-hailing app both there and in Saudi Arabia.
Concerns appeared to spread Monday to Japan's SoftBank, which has invested tens of billions of dollars of Saudi government funds. SoftBank was down over 7 percent in trading on Tokyo's stock exchange.
Saudi media took a hard line Monday, with newspaper headlines warning: "Don't Test Our Patience." The Arab News published a front-page editorial by Dubai-based real-estate tycoon Khalaf al-Habtoor that urged Gulf Arab nations to boycott international firms now backing out of the investment conference later this month.
"Together we must prove we will not be bullied or else, mark my words, once they have finished kicking the kingdom, we will be next in line," al-Habtoor said.
Fraser reported from Ankara, Turkey, and Gambrell reported from Dubai, United Arab Emirates. Associated Press writer Yuri Kageyama in Tokyo contributed.