In the wake of a hiring surge last summer, an official in charge of evaluating new recruits to U.S. Immigration and Customs Enforcement issued a dire warning. The Trump administration, he wrote in a memo, was cutting corners, violating the law and fast-tracking unqualified, “improperly vetted” candidates into ICE’s ranks, part of a dangerous move that exposed the agency — and its law enforcement operations — to “grave national security risks.”Citing an “unprecedented lowering of standards,” the career ICE official said that “systemic breakdowns” had allowed applicants to receive job offers before they had passed basic fingerprint, identity or credit checks in a preliminary vetting process. Political appointees had unjustly skirted background investigations and received national security eligibility.

The official, a unit chief who directly oversaw more than 100 employees who evaluated thousands of ICE applicants, was so troubled by what he saw that he outlined these concerns not to his superiors, but in a formal whistle-blower complaint to the Office of Inspector General in the Department of Homeland Security. In the complaint, he asked for an independent, outside investigation into the matter. He was later interviewed twice by officials with the inspector general’s office and his concerns have become part of an ongoing audit into vetting practices.