BUENA, N.J. – Sharif Mobley had strong Muslim views as early as high school. But his old friend Roman Castro knew he had radicalized when he saw him about four years ago.
Castro, an Army veteran who did a tour in Iraq, said Mobley had only these words for him in a chance meeting: "Get the hell away from me, you Muslim killer!"
Now, Mobley is in custody in Yemen as a suspected member of the same branch of al-Qaida that's linked to the failed Christmas Day bombing attempt of a Detroit-bound jet, and stands accused of killing a guard in an attempt to break out of a hospital, officials said Thursday.
Mobley, a former laborer at several nuclear power plants in the U.S., appears to be the latest example of the phenomenon of Americans joining terror movements overseas, which U.S. intelligence officials have warned of.
His case surfaces days after charges of terrorist connections were brought against Colleen LaRose, an American-born woman known as "Jihad Jane" who lived for years in Pennsylvania.
Mobley, a 26-year-old natural-born U.S. citizen, was identified by Yemeni officials as a Somali-American. A former neighbor said he moved to Yemen about two years ago, supposedly to learn Arabic and study Islam.
He was among 11 al-Qaida suspects detained this month in a security sweep in Yemen's capital of San'a this month. He was taken to the hospital over the weekend after he complained of feeling ill. He snatched a gun from a security guard and fatally shot one guard and wounded another before being captured, said Mohammed Albasha, spokesman for the Yemeni Embassy in Washington.
In Yemen, killing a guard during an escape attempt could result in execution by a firing squad.
U.S. officials fear that Yemen is becoming the next significant terrorist staging ground because of signs that lower-level al-Qaida operatives have been moving into the country, and the Pentagon has proposed spending $150 million to help Yemen battle insurgents.
The al-Qaida branch in Yemen was linked to the failed Christmas Day airliner bombing attempt. And Maj. Nidal Hasan, the Army psychiatrist accused of killing 13 people in a shooting rampage at Fort Hood last year, had exchanged e-mails with an extremist cleric in Yemen.
Americans are valuable to terrorist groups, in part because they can travel without arousing much suspicion.
"The U.S. passport is the gold standard," said Fred Burton, a former U.S. counterintelligence agent who is now a vice president at STRATFOR, a global intelligence company in Austin, Texas.
Mobley graduated from high school in 2002 in the rural southern New Jersey town of Buena, and later lived in Philadelphia and Newark, Del. Castro said that in the past few years, Mobley organized religious pilgrimages to the Middle East for other Muslims.
Mobley's mother, Cynthia Mobley, told WMGM-TV in Atlantic City, N.J., that her son is "an excellent person who's never been in trouble" and "a good Muslim."
As his father, Charles Mobley, pulled out of the family's driveway on the way to see a lawyer Thursday, he said, "I can tell you this: He's no terrorist."
Mobley worked for several contractors at three nuclear power plants in New Jersey from 2002 to 2008, PSE&G Nuclear spokesman Joe Delmar said. Mobley carried supplies and did maintenance work at the plants on Artificial Island in Lower Alloways Creek, and worked at other plants in the region as well.
He satisfied federal background checks as recently as 2008, Delmar said, adding that PSE&G is cooperating with authorities.
Mike Drewniak, a spokesman for New Jersey Gov. Chris Christie, said that his office had been told that Mobley was always supervised, caused no problems and was not believed to have breached security at the plants.
And Albasha said there was no immediate connection between Mobley's activities in Yemen and his work at the plants.
Joe Szafran, a spokesman for Exelon Corp., which owns nuclear plants at three facilities in Eastern Pennsylvania, referred all questions about whether Mobley worked there to the FBI.
An FBI spokesman did not immediately return a call, but a law enforcement official told The Associated Press that authorities don't believe Mobley's job at the nuclear plant was related to his activities in Yemen. The official spoke on condition of anonymity because he was not authorized to discuss the matter.
Abdel-Hadi Shehata, imam of the Islamic Society of Delaware, said Mobley lived in his apartment building and had a wife and a young daughter before moving to Yemen about two years ago.
Umar Hassan-El, assistant imam at the Islamic Society of Delaware's mosque in Wilmington, Del., said he roomed with Mobley during a 2004 pilgrimage to Mecca.
The worst Mobley did, Hassan-El said, was forget to pick up his clothes or interrupt discussions among older Muslims.
"He gave no indication that he would join a group that he's alleged to be a part of right now," said hassan-El. "I never heard that boy ever talk about shooting anybody, killing anybody."
Contributing to this report were Associated Press writers Geoff Mulvihill in Haddonfield; Matt Apuzzo and Lolita Baldor in Washington; Randall Chase in Newark, Del.; Ben Nuckols in Baltimore; and Ahmed al-Hajj in San'a.