Even to his sons, whose mother died when they were young, Menepta has long been an enigma. He took pains to imbue them with survival skills and Islamic principles yet seemed indifferent to their everyday worries about grades or friends. By the time they were in high school, he went abroad for weeks at a time without explanation. His sons admired and resented him for valuing his religion over their well-being.

Nattily dressed in old photos, Menepta now wears jeans and a T-shirt that hangs loose on his skinny frame. He lost 30 pounds in prison earlier this decade, as well as most of his teeth—broken, he says, by guards after he took a swing at them for harassing a Muslim inmate. Sometimes he weeps or rages. When asked about the F.B.I., he says, “Excuse me, I’m getting riled up,” strides into the next room, and punches the wall.

“They had the audacity to call me a terrorist,” he says later. “I told them, ‘I’m the victim of your terrorism.’ ”

He remains guarded about his past. When I ask about his travels, he rattles off innocuous destinations like Holland and the Canary Islands. Africa? He says he’s never been there. The next day, flipping through a family photo album, we come upon a camel. “That’s Gus!” he exclaims, adding that the picture was taken during a visit to Senegal in 2000.

Born Melvin Lattimore in 1950 in St. Louis, he was the youngest of 12 siblings. He played football, boxed and, like thousands of other black teenagers in the turbulent 1960s, took up radical politics. He says he belonged to the Black Panther Party and was drawn to Elijah Muhammad’s Nation of Islam. After serving 13 months in Vietnam, he was convicted of aggravated robbery in Colorado in 1971 and imprisoned for three years.

Once out, he found a job as a Southwestern Bell salesman. In 1979, he married a nurse, Tina Goodman, and they settled in Wichita, Kansas. Muhammad, whose birth name was Drew-Amun, was born in 1981, and Khalid a year later.

Tina succumbed to breast cancer in 1986; her young sons helped shovel dirt into her grave. Soul-searching, her widower gravitated toward fundamentalist Islam. In 1989, he quit his telemarketing job at AT&T in Atlanta, where his former boss would describe him as “our very best supervisor out of a team of 22.” He changed his name to Mujahid (meaning “holy warrior”) Abdulqaadir Menepta, and his older son’s to Muhammad. They moved from a one-and-a-half-acre refurbished plantation to an Oklahoma City apartment near the mosque of Menepta’s spiritual mentor.

That same year, Menepta spent four months in Pakistan, then the staging ground for Muslims battling the Communist regime in Afghanistan. His sons stayed home with their stepmother, whom Menepta had married in 1987. According to a 2004 Department of Justice report, Menepta made the trip with an Islamic missionary group sometimes used as a cover to recruit terrorists. The group is not identified, but Menepta says it was the Pakistan-based Tablighi Jamaat, described by its leaders as apolitical. He returned to Pakistan for six weeks in 1990, according to F.B.I. records.

Menepta’s Pakistan trips drew authorities’ attention in 1993, after a car bomb detonated in a parking garage beneath the World Trade Center. Secret Service agents informed him that one of the terrorists had used the number of his Pakistani travel visa, presumably to flee the U.S. Menepta was never charged. He maintains that while evangelizing in Pakistan, he’d stored the visa in a mosque, where somebody could have copied it.

Chronically restless, Menepta moved his family back to St. Louis, where in 1992 he and his sons renovated an abandoned bakery in the crime-ridden Walnut Park neighborhood into a mosque. With police backing, Menepta and a handful of helpers drove drug dealers and hookers away from the surrounding streets.