Adam Yahiye Gadahn, the young man from Southern California sought by the F.B.I. for questioning in a global terrorism investigation, was a troubled youth from an unconventional background who was looking for a place in the world, relatives said.

He appears to have found that place somewhere in Pakistan, where he fled more than five years ago to study and work among fellow Muslims, family members said. Mr. Gadahn, 25, converted to Islam at 17, saying he found the faith more peace-loving and rational than the nondenominational Christianity of his parents, who home-schooled Adam Gadahn and his three siblings.

Relatives portrayed Mr. Gadahn as an earnest pacifist seeking a simpler and less materialistic life than he had found in California. His father, Philip Gadahn, a goat farmer and carpenter in rural Riverside County, said he had not seen his son in five years or talked to him in more than two years. He said he had no reason to believe his son had joined Islamic militants or terrorists.

''If he is involved, it's all news to us,'' Philip Gadahn said in an interview on Thursday near his farm outside Winchester, Calif. ''We didn't have any inclinations.''

Philip and Jennifer Gadahn lived an isolated life with their children ''off the grid,'' relatives said, seldom watching television or using a telephone. So he could sell his goat meat in an Arabic market in Los Angeles, Philip Gadahn slaughtered the animals according to Muslim strictures.

Adam Gadahn said in an essay about his conversion to Islam, ''Having been around Muslims in my formative years, I knew well that they were not the bloodthirsty, barbaric terrorists that the news media and the televangelists paint them to be.''

Philip Gadahn said that F.B.I. agents visited his farm late Wednesday afternoon, the first time he had heard from the authorities about his son. He said he told the agents he did not know where his son was, but did not elaborate on the interview.

F.B.I. officials, in announcing that they were seeking to interview Adam Gadahn, said he had trained at Qaeda or Taliban camps in Afghanistan and had worked as a translator for Islamic militants. They said he had worked with Abu Zubaida, a senior Qaeda member who was captured by American agents in April 2002.

An F.B.I. wanted poster says that the bureau has no information linking Mr. Gadahn to specific terrorist activities but warns that he should be considered armed and dangerous. It lists several aliases, including Abu Suhayb Al-Amriki, Abu Suhayb, Yihya Majadin Adams, Adam Pearlman and Yayah.

There is an arrest warrant for Mr. Gadahn in Orange County arising from an assault at a Garden Grove, Calif., mosque in 1997, according to court records. Mr. Gadahn pleaded guilty to assault and battery in June 1997 and was sentenced to two days in jail and 40 hours of community service. When he did not show up for the community service, an arrest warrant was issued, according to court documents.

Dr. Muzammil Siddiqi, the imam of the Islamic Society of Orange County, said Mr. Gadahn was working as a guard or janitor at the mosque when Haitham Bundakji, an elder of the mosque, upbraided him about his work habits. Mr. Gadahn turned on Mr. Bundakji and hit him twice, Dr. Siddiqi said, but did not cause serious injuries. Mosque officials reported the incident to the police, he said.

Dr. Siddiqi said that Mr. Gadahn was a quiet young man who appeared devout when he sought conversion in late 1995. But over time he became increasingly distant, Dr. Siddiqi said.

''He was unhappy about something,'' he said. ''He was not communicating.'' After the 1997 incident with Mr. Bundakji, the imam expelled Mr. Gadahn from the mosque and told him never to return. He apparently left the country shortly after that, family members said.

Dr. Siddiqi said he was nonetheless shocked that Mr. Gadahn was wanted in connection with terrorism. ''I never thought that he would go to that level,'' he said.

Nancy Pearlman, Philip Gadahn's sister, said on Wednesday that she was ''extremely shocked'' to learn that federal authorities were seeking her nephew. She said that when she last spoke to him, about 18 months ago, he was in Pakistan. He had recently married an Afghan refugee and they were expecting a child. She said she had no reason to believe he had fallen in with Islamic militants.

''As far as I know, there's no connection, and I hope I'm proven correct,'' said Ms. Pearlman, an environmentalist and educator who lives in Los Angeles.

She said that before Mr. Gadahn left the country in the late 1990's he was going through a phase of questioning the family's religious beliefs and the American political system. But, she added, she never heard him espouse terrorism as a legitimate answer to the country's ills.

F.B.I. officials said this week that in addition to Mr. Gadahn, they were seeking six other suspected Qaeda operatives or sympathizers. All of them have previously been identified as potentially linked to terrorism. According to the Associated Press, they are:

Adnan G. El Shukrijumah, a Saudi native who used to live in South Florida. He is nicknamed Jafar the Pilot and is thought to be the leader of a possible terrorist cell.

Aafia Siddiqui, a Pakistani woman who studied at the Massachusetts Institute of Technology and Brandeis University. She is thought to be a facilitator of Qaeda operations in the United States because of her knowledge of the language and culture. The F.B.I. issued a global alert for her arrest in March 2003.

Fazul Abdullah Mohammed, a native of Comoros in the Indian Ocean, who is thought to be a senior Qaeda operative in East Africa. He was indicted in the United States for a role in the 1998 bombings of American embassies in Kenya and Tanzania, which killed 231 people.

Ahmed Khalfan Ghailani, a Tanzanian who also goes by the names Foopie, Fupi and Ahmed the Tanzanian. He is also under indictment for the embassy bombings.

Amer El-Maati, a pilot born in Kuwait, who is wanted for questioning on reported links to Al Qaeda.

Abderraouf Jdey, a Tunisian with Canadian citizenship, who was seen on videotaped messages found in Afghanistan at the home of Mohammed Atef, a military lieutenant to Osama bin Laden. Mr. Jdey's last known residence was in Montreal.