Neighborhood teenagers say Martinez kept to himself and came outside only to watch his little brother play. He usually wore a black-and-white checked head covering and sometimes knelt in the grass to pray, they said.
Naeem Rafiq, who owns the Al Makkah Halal Meat and Grocery in the Security Plaza shopping center, said Martinez sometimes came to the nearby Faizah-e-Madina Mosque. "He prayed with me two, three times a day," Rafiq said.
The Pakistan native, who has owned his store for 11 years, said Martinez started coming to the mosque about a year ago, but then switched to another one nearby, Al Madina.
"He goes to the other mosque. More than six months, I don't see him," Rafiq said.
He had just heard the news about Martinez's arrest from a brother-in-law who had seen a CNN report, and said he was surprised by it. "We don't like these things in my country," he said.
Martinez's former co-worker at the children's clothing store vividly recalls the day he announced his conversion. Asked why he took such a major step, "He said he met some people and started reading the Quran," the employee said.
She and fellow co-workers reminded him that Islam had suffered "bad publicity" in the United States, and Martinez acknowledged that both his mother and girlfriend at the time did not approve. But he was undeterred.
He told them, "This is something I feel I have to do," she said.
The ex-colleague said she "never had any inkling" that Martinez harbored anti-American views. In fact, she said, he told co-workers he once tried to join the Army, something court documents say Martinez also told an FBI informant.
Martinez's public Facebook page provides a window into his views, which appear to have been formed by the time of his first post, in August: "When are these crusaders gonna realize they cant win? How many more lives are they willing to sacrafice."
Sometimes his posts were unremarkable. On Sept. 14: "thanks 4 da happy bdays everybody."
More common were postings of videos that glorified "jihad" and statements that praised, among others, Anwar al-Awlaki, a U.S.-born cleric linked to last year's shooting at Fort Hood, Texas, that killed 13.
In late September, Martinez wrote: "The sword is cummin [and] the reign of opression is about 2 cease inshallah."
Kojo Ghana, who describes himself on Facebook as Martinez's brother-in-law, tried to temper his emotions. "Until that day comes Muhammad. Help those who are in need of help, volunteer at a food bank, tutor, or something Constructive."
In mid-October, Martinez posted the following: "Do you really want to spend your entire lives praying for longevity? WE were born in order to die."
Again, Ghana counseled restraint. "Yes," he wrote, "but we shouldn't be looking to die either. There's always balance in Islam, only Allah knows when each persons number is up…" Ghana did not respond to a message Wednesday.
By late October, according to court records, Martinez seemed intent on attacking the military recruiting center on Route 40. He claimed to know someone who could provide weapons and he detailed how he could enter the facility from the roof and "shoot everybody in the place."
Last week, in a recorded conversation that is detailed in court documents, Martinez sounded content with his choices. "Glad I am not like everyone else my age, 21 — going out, having fun, be in college, all that stuff. That's not me…that not what Allah has in mind for me."
Sun reporters Frank D. Roylance, Jean Marbella, Julie Scharper, Tricia Bishop and Justin Fenton contributed to this report. The Associated Press also contributed to this article.