Students from Saudi Arabia studying on government grants at American public universities are committing crimes, then vanishing while out on bail with the help of the Royal Consulate.

A recent news investigation revealed at least five cases of Saudi students facing serious crimes in Oregon in recent years who vanished before their trial or did not complete their jail sentence, including some who later reappeared in their home country, the Associated Press reports.

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In all of the cases – which range from accusations of rape, to a deadly hit and run, to child pornography – all involved young men studying at public Oregon colleges or universities with financial assistance from the Kingdom of Saudi Arabia. In four of the cases, the Saudi government posted large bail payments and seemingly covered legal costs, and three of the accused were ordered to surrender their passports.

Despite the precautions, all five men – who were represented by the same attorney, Ginger Mooney – disappeared before their cases were resolved.

Oregon Sen. Ron Wyden sent a letter to Trump cabinet members on Friday about the situation, pointing out how the cases reveal a troubling trend.

“These are shocking claims in any event,” Wyden wrote Secretary of State Mike Pompeo and Acting Attorney General Matthew Whitaker, “but with the barbaric murder of U.S. resident Jamal Khashoggi, they suggest a brazen pattern of disregard for the law and abuse of diplomatic privileges.”

The AP reports more than 44,000 Saudis attend schools in the U.S. this year, and about 1,000 of them are enrolled in Oregon colleges and universities. Those figures have surged since the oil-rich nation created a generous scholarship program for citizens in 2005 that covers full tuition, a monthly stipend and other incentives to attend American schools.

The majority seem to focus on degrees in business, engineering and architecture, while a handful face run-ins with law enforcement. In 2016, 20-year-old Portland Community College student Abdulrahman Sameer Noorah was allegedly speeding when he struck and killed 15-year-old Portland high-schooler Fallon Smart as she legally crossed Southeast Hawthorne Boulevard.

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Noorah was charged with first-degree manslaughter, felony hit-and-run and reckless driving, but he never made it to his June 2017 trial. Records show the Saudi Consulate hired Mooney to work his case and paid $100,000 to secure his bail.

Once out of jail, Noorah cut the electronic ankle monitor issued by the court and disappeared. Federal investigators told The Oregonian witnesses allege he was escorted away in a black SUV and authorities believe he was flown back to Saudi Arabia with a fake passport on a private plane.

A year after his disappearance, the Saudi government informed the U.S. Department of Homeland Security Noorah was back home.

Saudi student Abdulaziz Al Duways is another example.

Al Duways, a Western Oregon University students, was arrested in Monmouth in December 2014 and charged with raping a classmate he plied with marijuana and whiskey, though he was never held accountable.

Al Duways was arraigned on multiple felony counts, including first-degree rape, and a judge set his bail at $500,000. The judge also ordered Al Duways to surrender his passport to Mooney.

The Saudi Consulate in Los Angeles posted his bail on Dec. 29 and Al Duways disappeared before his next scheduled court appearance, the AP reports.

Saudi students facing crimes including repeated drunken driving and child pornography have also eluded justice.

The situation isn’t sitting well with Wyden, who is calling on the Trump administration to launch a broader investigation into the issues in Oregon and elsewhere.

“Secretary Pompeo and the Justice Department need to do a thorough investigation to determine the scope of this abuse in our justice system,” he wrote, “and start by answering the questions I asked.”

Those answers, however, could take a while, the AP reports.

“The FBI, State Department and Department of Homeland Security did not comment for this story, citing staff reductions and furloughs during the federal government shutdown,” the news service reports. “The Justice Department did not respond to a request for comment.”