Moner Mohammad Abusalha, the 22-year-old Florida man who became an al-Qaida suicide bomber, returned home for several months after his initial training,
The New York Times reported.
Counterterrorism authorities knew little about Abusalha's comings and goings and say it is hard to identify and track U.S. citizens like him, much less understand what propels them to join al-Qaida.
After returning to Syria, Abusalha killed 37 soldiers loyal to the Assad regime by driving an explosive-laden truck into their compound in May.
"This incident exemplifies the challenges faced by the FBI in detecting U.S. citizens who seek to travel to Syria to engage in jihad," bureau spokesman Michael Kortan told the Times.
Abusalha joined the Nusra Front, which is aligned with al-Qaida and committed to bringing down the Shiite-affiliated government of Bashar Assad. U.S. authorities had no idea about his training or his plans, which they found out about only after he was back in Syria.
The Nusra Front issued a
propaganda video in which Abusalha describes some of his journey — literally and philosophically — from America to his jihadi camp in Syria.
Rambling in English with some Arabic phrases thrown in — his father is of Palestinian origins — he said that in America he sometimes had to scrounge for food in dumpsters. "I lived in America; I know how it is," he said. "You think you're happy? You're not happy. You're never happy. I was never happy. I was always sad and depressed," according to the Times.
He said he had very little money for the journey to Istanbul, Turkey, but that once he was accepted by the jihadists, all his material needs were looked after. He does not reveal how the jihadists moved him into Syria.
Sharing a cup of tea with the jihadists was better than all the material comforts of American life. He had never been happier, he said.
Abusalha declared that jihad was neither evil nor terrorism.
"You think you are safe; you are not safe," he said. Later in the video, he also threatens Israel.
He said he sought to convince other Americans to join him in Syria. At least 100 Americans have received training there, the Times reported.
Abusalha was not the only jihadist to return home after training. Others include 2010 attempted Times Square car bomber Faisal Shahzad, who was trained in Pakistan before his failed attack, and David Headley, also known as Daood Sayed Gilani, who carried out reconnaissance for the Pakistan Taliban in India while traveling back and forth from the United States, the Times reported.