Hasan’s contacts with extremist imam Anwar al-Aulaqi began as religious queries but took on a more specific and concrete tone before he moved to Texas, where he allegedly unleashed the Nov. 5 attack that killed 13 people and wounded nearly three dozen, said the sources who were briefed on the e-mails, speaking on the condition of anonymity because the case is sensitive and unfolding. One of those sources said the two discussed in “cryptic and coded exchanges” the transfer of money overseas in ways that would not attract law enforcement attention.

In the months before the shootings, the two discussed how Hasan could make several transactions of less than $10,000, a threshold for reporting to U.S. authorities, according to the source who spoke extensively. Hasan did not explicitly vow to fund terrorist activities or evade tax and reporting laws for contributions, the source said. “I believe they were interested in the money for operational-type aspects, and knowing that he had funds and wouldn’t be around to use them, they were very eager to get those funds,” he said.