learned of more cases in which Saudi suspects have eluded American justice, apparently with their government's help. But US 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.

Officials offered several reasons for Washington's lack of action

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.

Read more: Trump issues second veto of his presidency, rejectingnot 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