When officials pulled Sinh Vinh Ngo Nguyen off a bus bound for Mexico, they said the security guard was headed to Lebanon and planned to make his way across its rugged terrain into Syria.
Traveling under the name Hasan Abu Omar Ghannoum, the 24-year-old — who grew up in middle-class Orange County in the bustling Little Saigon community — had made plans to join the terrorist group Al Qaeda, authorities say.
Family members, though, painted a far different picture, that of a faith-driven man who was raised a Catholic, once spent hours talking with Mormon missionaries and converted to Islam a year ago.
They described Sinh Nguyen as a thoughtful person who lived at home, continued to attend Mass with his mother and had become more settled once he explored the teachings of different religions.
"He never supported Al Qaeda," an older brother, who identified himself as T. Nguyen, said in an interview Monday at the family's modest Garden Grove home.
He said his brother studied the Bible and the Koran, and added that they engaged in long discussions about spiritual issues. "He was pretty open-minded about religion," T. Nguyen said.
Sinh Nguyen, he said, is the fourth of six children — all of them born in the United States to immigrant parents.
Authorities in possession of a a search warrant showed up at the family home early Friday and combed Sinh Nguyen's bedroom, confiscating computers and a cellphone. T. Nguyen said the agents moved quickly and that by the time his grandparents had returned from their morning walk, the agents had left.
About the same time, Nguyen was detained as he boarded a bus in Santa Ana. Family members would not say if they knew about his travel plans.
Two Facebook pages appear to be owned by Nguyen. Both use the name Hasan Abu Omar Ghannoum and one has photos that appear to be of Nguyen. One of the posts documents a trip he made last year to Lebanon and a crossing late last year into Syria, where he remained for several months.
The Facebook descriptions recount traveling across difficult terrain, preparing to "fight against Assad and his minions" and avoiding snipers before arriving at a village in central Syria in December.
"I got my first confirmed kill about two weeks ago," a post dated Feb. 4 said. "So pumped to get more."
Authorities confirmed that Nguyen previously traveled to Syria but provided no details on his activities there.
Another Facebook page with the same name, highlighting photos that appear to be of Nguyen, contains two videos from 2010 that appear to show him shooting at a Huntington Beach firing range.
A series of questions and answers on the profile said he worked in security, had a high school education, favored a .45-caliber handgun, enjoyed the video game Battlefield 3 and disliked Justin Bieber and Miley Cyrus. Before the Tet Festival in February, he posted a note in Vietnamese wishing "happy new year" to his grandparents.
"It has been more than 3 months [since] I have been back," said an Aug. 18 post. "After I left my brother's country, I have so many regrets of leaving my brothers and sisters who are still suffering over there.... I'll be back there."
The page, which was public Friday, had been disabled or deleted by Monday.
Nguyen is being held without bail and is scheduled to return to court Friday.
Times staff writer Richard Winton contributed to this report.