At the time, the CIA would have done its own vetting of him through a variety of databases, including the National Counterterrorism Center database, to see if he had any known ties to terrorist groups. The CIA did its own vetting before he started working with them and kept the identities of those they worked with secret, the official said.
NCTC would have vetted him again during Operation Allies Welcome in 2021 for any ties to terrorism before he was allowed into the US. He was clean then as well and did not show any ties to terror organizations, per the senior US official.