Roman Castro, 25, who did a tour with the Army in Iraq, said the last time he saw Mobley, about four years ago, Mobley called him a Muslim killer.
The FBI, the State Department, and other authorities said they were trying to gather information about Mobley. But the allegations appeared to illustrate a phenomenon US intelligence officials have warned about: American Muslims becoming radicalized and joining terrorist movements overseas.
Mobley, a 26-year-old natural-born US citizen, was identified by Yemeni officials as a Somali-American. Mobley moved to Yemen about two years ago, supposedly to learn Arabic and study Islam, a former neighbor said.
Before that, Mobley worked for several contractors at three nuclear power plants in New Jersey from 2002 to 2008, said Joe Delmar, PSEG Nuclear spokesman. Mobley carried supplies and did maintenance work at the plants.
He satisfied federal background checks as recently as 2008, Delmar said, adding that the plant is cooperating with authorities.
Mike Drewniak, a spokesman for Governor Chris Christie of New Jersey, said his office had been told that Mobley was always supervised, caused no problems, and was not believed to have breached security.
Also, Mohammed Albasha, spokesman for the Yemeni Embassy in Washington, said there was no immediate connection between Mobley’s activities or capture in Yemen and his work at the plants.
Mobley was arrested in Yemen in a roundup of suspected Al Qaeda members this month and was being treated at a hospital in Sana when he got into a shoot-out with guards during an escape attempt, killing one and wounding another, said Mohammed Albasha, spokesman for the embassy.
US officials worry that Yemen is becoming the next significant terrorist staging ground because of signs that lower-level Al Qaeda operatives have been moving into the country from the Afghanistan-Pakistan border region.
The Al Qaeda branch in Yemen was linked to the failed Christmas Day bombing of a Detroit-bound airliner. Also, Major Nidal Hasan, the Army psychiatrist accused of killing 13 people in a shooting rampage at Fort Hood, Texas, last year, had exchanged e-mails with an extremist cleric in Yemen.
In response to the threat, the Pentagon has proposed spending $150 million to help Yemen battle insurgents within its borders.
Mobley was among 11 Al Qaeda suspects detained this month in a security sweep in Sana, the capital, officials said. He snatched a gun from a security guard at the hospital and shot him, then got into a shoot-out that ended with antipolice terrorism capturing him, authorities said.
As his father, Charles, pulled out of the family’s driveway yesterday, he said, “I can tell you this: He’s no terrorist.’’
