The government of Saudi Arabia has repeatedly helped Saudi citizens evade prosecutors and the police in the United States and flee back to their homeland after being accused of serious crimes here, current and former U.S. officials said.

The FBI, the Department of Homeland Security and other agencies have been aware of the Saudi actions for at least a decade, officials said. But successive American administrations have avoided confronting the government in Riyadh out of concern that doing so might jeopardize U.S. interests, particularly Saudi cooperation in the fight against Islamist terrorism, current and former officials said.

“It’s not that the issue of Saudi fugitives from the U.S. wasn’t important,” said retired FBI agent Jeffrey Danik, who served as the agency’s assistant legal attache in Riyadh from 2010 to 2012. “It’s that the security relationship was so much more important. On counterterrorism, on protecting the U.S. and its partners, on opposing Iran, the Saudis were invaluable allies.”

American officials said Saudi diplomats, intelligence officers and other operatives have assisted in the illegal flight of Saudi fugitives, most of them university students, after they were charged with crimes including rape and manslaughter. The Saudis have bailed the suspects out of jail, hired lawyers to defend them, arranged their travel home and covered their forfeited bonds, the officials said.

A spokesman for the Saudi Embassy in Washington, Fahad Nazer, said that only “a small fraction” of Saudi students in the United States have gotten into legal trouble, and that Saudi officials have “strictly adhered to all U.S. laws” in helping them. “The notion that the Saudi government actively helps citizens evade justice after they have been implicated in legal wrongdoing in the U.S. is simply not true,” he said. He did not respond to questions about how a series of Saudi students had managed to return home while facing criminal charges in the United States.

The Trump administration has deflected calls for an accounting of the Saudi government’s role in the flight of fugitives, asserting that there is little the United States can do because it has no extradition treaty with the kingdom. This week, the State Department said for the first time that it has raised the issue with senior Saudi officials, but it would not specify when or how.

“The U.S. government takes this seriously,” said a State Department spokeswoman, who would only respond to ProPublica’s questions on condition of anonymity.

The repeated flight of Saudi students from U.S. justice was revealed in a series of recent articles in The Oregonian/OregonLive, with which ProPublica is now collaborating to report on the issue. Those articles have identified more than 20 cases since 1988 in which Saudis have fled from legal troubles — before and often after being charged with crimes — in the United States and Canada. The extent of the Saudi government’s role in helping such fugitives and the fact that U.S. national security agencies have long known of it have not previously been reported.

U.S. officials said the problem of Saudi students fleeing prosecution had increased as the Saudi student population in the United States has exploded, rising from fewer than 5,000 in 2005 to more than 80,000 a decade later, according to DHS figures. The Saudi government has sponsored most of those students under a $3 billion scholarship program created by the late King Abdullah.

The students are dispersed widely around the United States, attending schools from Oregon State University to Western Illinois University to Southern New Hampshire University. The program has brought a bounty of full-freight tuition payments to dozens of state and private institutions and introduced a new generation of Saudis to life outside the regimented confines of the kingdom.

A former senior national security official said DHS first focused on the issue of Saudis evading justice in 2008, when an intelligence unit tracking foreign students noted a pattern of Saudis disappearing back to their homeland after they had been charged with crimes in the United States.

DHS analysts identified several Saudi officials who had assisted in the repatriation efforts while working out of the Saudi Arabian Cultural Mission, a government agency that both supports and monitors Saudi students in the United States. At least some of the officials at the Cultural Mission appeared to be intelligence officers working undercover, the former senior official said.

Since then, DHS and other agencies have learned of more cases in which Saudi suspects have eluded American justice, apparently with their government’s help. But U.S. law enforcement agencies still have only a sketchy understanding of how some of the Saudi suspects escaped the United States and the role that Saudi operatives played, officials said.

Instances of misconduct by foreign diplomats are typically raised by State Department officials in meetings with foreign envoys in Washington and overseas. But none of the more than two dozen current and former officials interviewed for this story said they knew of any formal protest about the issue prior to the State Department’s new assertion that it has discussed the matter with Saudi leaders.

“I would not have hesitated to go to anybody — whether the crown prince or the deputy crown prince or the foreign minister — to bring up something that was distasteful or difficult,” said Joseph W. Westphal, who was the United States ambassador in Riyadh between 2014 and 2017. “It would not have been something that I shied away from if it was affecting the relationship. But it was not something that came to my desk.”

Officials offered several reasons for Washington’s lack of action. In some cases, state or local law enforcement officials had taken months to contact federal agencies to seek warrants for the suspects’ arrests for unlawful flight from prosecution. In other instances, local officials did not appear to have contacted federal agencies at all.

Although many current and former officials acknowledged having heard about individual cases of Saudis fleeing justice, some of them said they did not see a clear pattern emerge. American officials dealing with Saudi Arabia have also long been accustomed to the kingdom’s overarching concern with its image in the United States, and to the extraordinary lengths to which Saudi diplomats would often go to avoid negative publicity.

Within the federal government, information about the Saudi cases has been scattered across several agencies, none of which have had much incentive to address the problem. FBI and CIA officials in Saudi Arabia have concentrated on preserving Saudi cooperation in the fight against Islamist terrorism; matters that might jeopardize that goal have often been avoided, officials said.

For decades, Saudi Arabia’s vast oil wealth and its strategic influence in the Middle East have ensured similar deference from the State and Defense departments and the National Security Council staff. The bilateral relationship became strained after the 9/11 attacks, in which 15 of 19 hijackers were Saudi members of al-Qaida, and during the American occupation of Iraq. But the Obama administration made a concerted effort to overcome those tensions, and the Trump administration has gone further, refusing to hold the Saudi leadership accountable even after the CIA concluded that the powerful crown prince, Mohammed bin Salman, had likely ordered the murder of Jamal Khashoggi, a Saudi columnist for The Washington Post.

Since late December, Sen. Ron Wyden, an Oregon Democrat, has pressed the departments of State, Justice and Homeland Security for information on the Saudi government’s actions in helping to repatriate Saudi students who faced criminal charges here. Wyden voiced particular outrage about the case of Fallon Smart, a 15-year-old Portland girl who was struck and killed by the speeding car of a Saudi college student in 2016.

That student, Abdulrahman Sameer Noorah, was freed from a Portland jail after the Saudi consulate in Los Angeles gave him $100,000 to cover his $1 million bail. He surrendered his passport and driver’s license to Homeland Security officials. But on a Saturday afternoon in June 2017, two weeks before Noorah was to go on trial for manslaughter, a large, black SUV picked him up at the home where he was staying and spirited him away. His ankle monitoring bracelet was later found by the roadside; a week later, he was back in Saudi Arabia — a fact that the authorities in Oregon did not learn until more than a year later.

Federal officials would not discuss their evidence in the case, but they said they believe it shows that the Saudi government helped Noorah flee the country. Investigators suspect that Saudi operatives provided the student with a replacement passport and may also have arranged for him to escape on a private jet, officials of the U.S. Marshals Service said.

But while the police found a trail of clues — including cellphones, a laptop and surveillance camera footage of the black SUV — the State Department has asserted that U.S. officials had “no concrete, credible evidence as to how Mr. Noorah effected his escape.” Without an extradition treaty, the department added in a letter to Wyden in February, there was little chance that he could be made to face justice in the United States.

“Are you as disturbed as I am that Saudi nationals have a get-out-of-jail-free card that allows them to commit abuses against children, manslaughter, rape and have no accountability?” Oregon’s other U.S. senator, Jeff Merkley, also a Democrat, asked retired Army Gen. John Abizaid last month during a hearing on his confirmation to become the administration’s ambassador to Riyadh. “When a person commits a crime in the United States, we shouldn’t — because they’re an ally that buys a lot of stuff from us — allow them to whisk their citizens out.”

While law enforcement and diplomatic officials have met to discuss the Noorah case, they insisted privately that there is little more they can do. Nor is the Trump administration considering any complaint or sanction against the Saudi government for its role in abetting the flight of Noorah and other Saudi fugitives, officials said.

The FBI and the Justice Department declined to comment for this article. An FBI spokeswoman said she could neither confirm nor deny the existence of any investigation.

In 2008, intelligence analysts at the headquarters of Immigration and Customs Enforcement spotted a striking trend, national security officials recalled. The analysts, who monitored potential terrorist and criminal threats related to foreign students, noted a series of calls to an ICE office from a Saudi official in Washington.

The official worked at the Saudi Arabian Cultural Mission, a branch of the country’s diplomatic operation that was then located in a building near the Watergate office complex. He called periodically to ask about the visa status of various Saudi students. On further examination, the analysts found that some of the students had been charged with crimes including rape, embezzlement and theft, and that they had unlawfully fled the country, a former senior national security official said.

The mission, established in Washington in 1951, administers government scholarships overseas and helps prepare the visiting students for life in a culture very different from their own. If they ever run into trouble, they are instructed to call the mission. (If they did not, they could expect Saudi officials to call them.) Based on reporting by the FBI, U.S. intelligence analysts believed the cultural center also served as a base for undercover Saudi intelligence officers who kept tabs on the growing numbers of students in the United States.

While Saudi diplomatic activity was monitored by the FBI as part of its routine counterintelligence efforts, Saudi intelligence officers seemed to focus on what they considered misconduct by their own citizens — advocacy of Islamist radicalism, criticism of the kingdom or other “political” activity.

But the ICE analysts learned that the Saudi operatives would also intervene when a student ran into legal trouble. “The initial visit to the student in jail or court might be from their local consulate, but the intelligence officers at the cultural center would provide advice and guidance,” the former senior national security official said.

ICE officials saw some recurring features in about a dozen cases they scrutinized. In some instances, the Saudi suspects had managed to abscond even after local or state courts had confiscated their passports — raising questions about whether Saudi diplomats were providing them with new ones. Several fugitives had slipped into Mexico, apparently to circumvent U.S. immigration checks on their way home.

The ICE analysts wrote up their findings in a report that was shared within DHS. But the paper was not formally disseminated to the broader U.S. intelligence community and did not prompt any further investigation. “There were enough cases to constitute a pattern that rose to our attention, but there weren’t enough to generate the interest level for a full-fledged investigation,” the former senior official said. “Not to mention the diplomatic sensitivities.”

Those sensitivities had risen sharply after 9/11. While the immigration authorities tightened their screening of Arab and other visitors after the attacks, the FBI stepped up its scrutiny of Saudis in the United States. Concerned about apparent ties between al-Qaida and the Saudi elite, the FBI created two new units in Washington that brought together counterterrorism and counterintelligence agents to track the possible Saudi threat.

At an April 2005 meeting at the Texas ranch of President George W. Bush, Crown Prince Abdullah, who was already the de facto Saudi monarch, made a plea for the United States to reopen its doors to Saudi students. Abdullah told American friends that the experience of studying in the United States opened the minds of young Saudis, lessened the influence of his country’s fundamentalist Wahhabi clerics and strengthened the two countries’ alliance. “Part of it was having them learn about tolerance and diversity,” said Theodore Kattouf, a former U.S. ambassador in the Middle East who discussed the scholarship program with the Saudi king on several occasions.

Abdullah, who ascended to the Saudi throne later in 2005, gave his name to a major new program of government scholarships, extending subsidies to a far wider range of young people than had previously studied abroad. The king pressed his Washington allies to ease U.S. restrictions on student visas for Saudi applicants, and he found political leaders from both U.S. parties receptive to the idea that such exchanges would inevitably instill more liberal and pro-Western values in future generations of Saudi leaders.

President Barack Obama’s first ambassador to Riyadh, James B. Smith, overhauled the U.S. Embassy’s visa processing system soon after presenting his credentials in late 2009. The average wait time for a visa fell from almost four months to fewer than 10 days, he said in an interview, and by the time Smith left Riyadh in 2013, the census of Saudis studying in the United States had risen from 17,700 to 77,100, DHS figures show.

Although both countries pledged to screen the visa applicants rigorously, some FBI veterans saw the process as inadequate. “They interviewed people, they tried to do some due diligence, but it wasn’t much,” one former agent said.

The Saudi government also had its own screening procedures to identify militants, slackers and potential critics of the royal leadership, officials said. Before and sometimes after arriving in the United States, the students were briefed extensively on American social mores, with an eye to helping them to adapt to a culture radically different from their own.

A list of rules for Saudi students abroad, published by the Cultural Mission in 2017, forbids any political or religious discussions or any interviews with local news media. The students are also instructed that if they get into any trouble, or witness another Saudi student doing so, they must contact the Cultural Mission or one of the students who act as its semiofficial representatives on many college campuses.

“The Cultural Mission does keep tabs,” Smith said in an interview. “They have representatives at each of the colleges and universities, and they want to make sure that everyone behaves. They run a pretty tight ship.”

According to former U.S. national-security officials and Saudi students, the associations of Saudi students on many campuses act as an informant network for the kingdom’s intelligence services, reporting to Cultural Mission handlers or intelligence officers working under diplomatic cover. Officers of the associations, who are vetted and sometimes chosen by the Cultural Mission, report to it on meetings, activities and social media posts from other students, especially anything that might suggest Islamist militancy or criticism of the Saudi regime. Counterintelligence experts said the system resembles the approach used by China to spy on its students overseas.

“The student associations are an important part of the mechanism of control,” said Abdullah Alaoudh, a fellow at Georgetown University’s Center for Christian-Muslim Understanding, who was stripped of his Saudi government scholarship while studying law at the University of Pittsburgh. “That’s who denounced me for being a dissident. They report on you to the Cultural Mission, and the mission had a file on me with all my Twitter and Facebook posts.”

Nazer, the Saudi Embassy spokesman, said that the cases of students who have broken American laws represent “clear aberrations” among the hundreds of thousands of Saudis who have studied productively in the United States since the 1960s. He insisted they are not “a reflection on the large Saudi student population in the country, the overwhelming majority of which is law-abiding.”

In a number of cases since 2002, current and former officials said, FBI agents began investigating visiting Saudis for possible extremist ties only to have the visitors disappear. The Saudi government had gotten there first, possibly after conducting its own surveillance of social media platforms, or being warned by its student network, or becoming aware of the bureau’s surveillance.

One former federal law enforcement official described a 2014 incident in which a Saudi student reported to the Cultural Mission about Islamist material that two fellow students had posted on the internet. Although the content did not violate any American laws, the two students were sent home immediately.

“You’d be running a case against a guy, and the next thing you know, he would be gone,” said another former FBI official, Frank Montoya Jr., who headed the agency’s counterintelligence effort. “The bureau has struggled since 9/11 on whether or not we should see them as an ally in the fight against terrorism.”

Current and former national security officials said the Saudis’ interventions complicated their efforts to determine if the suspects were involved in wider plots or had accomplices. Often, the Saudis were not responsive to FBI requests for information about the suspects who had vanished, the officials added.

The Saudis’ early warning system had long protected members of influential families and other Saudi visitors to the United States. In order to safeguard the kingdom’s image, Saudi diplomats often hurried to repatriate businessmen, students or others who got into trouble, preferably before any legal action could be taken against them.

“There was a practice if somebody got into trouble where they called the embassy and the embassy would come and scoop them up before charges were filed,” Smith said. “The Saudis didn’t want any embarrassment. They would take them out in the middle of the night.”

National security officials said that system began to operate more frequently and sometimes more aggressively as the number of Saudi students in the United States grew. In one such case, Saudi officials put up $65,000 to cover the $650,000 bond of an 18-year-old student, Ali Alhamoud, after he was jailed on charges of raping a young woman in a small town near the Oregon coast. Within hours after he was bailed out of jail, Alhamoud boarded a plane and flew home, court records show.

“It’s essentially a rendition of their own citizens,” said David Rubincam, who took over as the FBI’s legal attache in Riyadh in 2008, just as the scholarship program was starting to grow. “There were a lot of less-visible situations where they would pull a student back. The more students, the more likelihood of problems. That’s just the math.”

Military and Homeland Security officials noted that under current U.S. procedures, foreign citizens would show up on border security watchlists only after they had been convicted of crimes; arrests and pending charges would not necessarily alert U.S. border officials or airlines.

Although members of Congress and others have long advocated for exit controls on visiting foreigners — and the lack of such controls was a pointed criticism by the 9/11 Commission — successive U.S. administrations have failed to impose them, citing high costs and cumbersome logistics.

The cases uncovered by The Oregonian/OregonLive have suggested that accused students made their way home with assistance from people knowledgeable about skirting the U.S. immigration system.

In 2014, Abdullah Almakrami fled from Milwaukee after he had been arrested on suspicion of sexual assault and false imprisonment. Although his passport had been seized, he surfaced months later in Saudi Arabia, where he posted comments on a social media account about food and the weather.

The following year, the Saudi Consulate put up the $500,000 bail for Waleed Ali Alharthi, a student at Oregon State University who was found to have a cache of child pornography on his computer and was charged with 10 counts of encouraging child sexual abuse. Although the court had confiscated his passport, Alharthi escaped to Mexico City — somehow obtaining a new passport along the way — and investigators believe he flew to Paris on his way back to the kingdom, officials say.

It is generally not possible to leave the United States by plane without a passport. National security officials said it was implausible that young Saudis on the run could obtain replacement passports or travel into Mexico by land without help. They suspect that Saudi operatives accompany or guide the fugitives.

The Saudi Embassy, unlike many others, routinely posts bail and hires criminal defense lawyers for its citizens when they are accused of crimes in the United States. But Nazer, the embassy spokesman, said it does not “issue travel documents to citizens engaged in legal proceedings.”

Danik, one of the former FBI officials who served in Riyadh, recalled dealing with cases of Saudis who fled despite the fact that U.S. courts had seized their passports. “I remember in some cases local police and U.S.-based FBI agents were angry,” he said. They would call the legal attache’s office in Riyadh afterward asking: ‘How did he get out of the U.S.?’ I told them if they’d have notified us beforehand, I could ve possibly filed an affidavit opposing bail because Saudis arrested in the U.S. were often a flight risk.

“There were no complaints we lodged with the Saudis,” Danik added. “That just wasn’t something that was going to happen.”

Although many former U.S. national security officials said they had been aware episodically of fugitives disappearing with suspected help of the Saudi government, the issue never rose anywhere near the level of pressing geopolitical concerns, current and former officials said. Chief among those concerns was ensuring the continued cooperation on counterterrorism issues of a secretive monarchy whose fundamentalist brand of Islam was widely considered to be a central force in the rise of Islamist terrorism.

“My job as legal attache was to get as much information as I could from the Saudis on terrorism,” a former FBI agent said. “If I am talking to them about their nationals committing crimes in the United States, it’s going to shut me down. It’s not my lane. It would be handled through diplomatic channels.”

Saudi Arabia became a critical partner for the CIA and FBI against a rising militant group that posed a surprisingly direct threat to the United States: al-Qaida in the Arabian Peninsula, or AQAP. The group, an offshoot of the Osama bin Laden organization, plotted repeatedly to bomb aircraft bound for the United States and came dangerously close in 2009 when a bomber with explosives hidden in his underwear nearly brought down a jetliner. Later, the Saudis became an important ally in the fight against ISIS, which included several thousand Saudi fighters and carried out attacks in Saudi Arabia.

Although the U.S. Embassy continued to receive periodic communications from the United States about Saudi fugitives evading justice, terrorism always dominated the workload, former officials said. Some former FBI agents said senior CIA officials in the kingdom, who had an even closer and more fruitful relationship with the Saudi security services, were especially reluctant to raise issues like the Saudis’ help to fleeing students.

Former FBI officials also said they believed their ambassadors — from both the Bush and Obama administrations — would have been reluctant to confront Saudi leaders over the matter. Several former senior diplomats who served in Riyadh disputed that notion, insisting that the discussion of such issues was an unavoidable part of their jobs. The two previous U.S. ambassadors, Smith and Westphal, said that they had only heard vague and isolated reports about Saudi students fleeing trouble in the United States, and that they had never been asked by either their subordinates or officials in Washington to raise the issue with the Saudi government.

But other foreign policy officials said there is an inherent danger in relationships like the U.S.-Saudi one that American diplomats and other officials try to avoid seemingly smaller, quotidian problems to focus on the highest-priority matters.

“There is always a risk for the officials who handle these bilateral relationships day to day that you follow the impulse to manage or even smooth over an issue, rather than stepping back and recognizing it as something serious that needs to be confronted,” said a former senior Obama administration official. “That is especially true with countries where our interests or values don’t align.”

Several former officials emphasized that FBI and CIA personnel in Saudi Arabia had a powerful sense of responsibility to protect Americans from terrorist attacks. But Fawn Lengvenis, the mother of the 15-year-old girl struck and killed in Portland, Fallon Smart, said the government had left her family and other Americans vulnerable to a different kind of threat.

“It’s heartbreaking to learn that our government has, for over a decade, known that the Saudi government has helped so many Saudi students charged with serious crimes skip bail and escape back to Saudi Arabia without any accountability,” she said in a statement.

Many former diplomats and national security officials also said they suspected the Saudi government had grown more brazen in support of its accused citizens as its defiance of local and state courts had been ignored by successive administrations in Washington. Given the Trump administration’s staunch backing for Crown Prince Mohammed in the aftermath of the Khashoggi murder, they added, many were skeptical that those circumstances would change.

“Right now, the Saudis think they have carte blanche in our country,” Montoya, the former FBI counterintelligence official, said. “Given the support that they are getting now, they literally can get away with murder.”