Federal officials say they withheld publicizing charges against the accused man until they were certain that he acted alone.

The U.S. Attorney’s Office and the FBI said 29-year-old Alexander White tried to make financial transactions in support of ISIS camps. Investigators said they found out about White from an overseas source who saw him posting online under the name “Sulaiman Al-Amriki,

Investigators learned that his flight was set for Dec. 4 from RDU with a return flight to the Triangle on Dec. 18. An FBI special agent noted that White likely purchased a round-trip ticket to avoid arousing suspicion, a common practice among Islamic extremists.