The FBI acknowledges knowing little about Tashfeen Malik. Those who attended mosque with her husband, Syed Farook, said they know nearly nothing of her. Even Farook's mother, who lived with the couple and their 6-month-old daughter, knows little, according to attorneys for Farook's family.
The lawyers on Friday described the 27-year-old as "just a housewife" who was quiet like her husband and strictly followed Muslim custom. She wore traditional clothing that covered her face so her brothers-in-law didn't even know what she looked like, according to the lawyers who represent Farook's mother and three siblings.
Authorities say she ditched the Muslim garb for a combat-style outfit Wednesday, when she and Farook attacked a training session and holiday luncheon in San Bernardino. A few hours later, they were killed in a shootout with police.
The FBI announced Friday it is investigating the mass shooting as an act of terrorism. If proven to be terrorism, it would be the deadliest attack by Islamic extremists on American soil since Sept. 11, 2001. A U.S. law enforcement official said Malik used a Facebook alias to pledge her allegiance to the Islamic State group and its leader just before the shootings.
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FBI Director James Comey would not discuss whether anyone affiliated with the Islamic State communicated back to Malik, but he said there was no indication yet that the plot was directed by ISIS or any other foreign terror group. He also declined to rule out that possibility based on further investigation.
"The investigation so far has developed indications of radicalization by the killers and of potential inspiration by foreign terrorist organizations," Comey said. He cautioned that the investigation has not yet shown evidence the couple was part of a larger group.
Despite mounting signs of the couple's radicalization, there "is a lot of evidence that doesn't quite make sense," Comey said in a nod to the fact that the investigation was just two days old.
David Bowdich, assistant director of the FBI's Los Angeles office, said "a number of pieces of evidence" point to terrorism and that the agency was focused on that idea "for good reason." He would not elaborate.
The U.S. official who revealed the Facebook post was not authorized to discuss the case publicly and spoke on condition of anonymity.
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The Facebook official, who also spoke on condition of anonymity because the person was not allowed under corporate policy to be quoted by name, said the company discovered Wednesday's post on Thursday, removed the profile from public view and reported its contents to law enforcement.
Bowdich said he was not aware of the Aamaq report but was not surprised IS would attempt to link itself to the attack. He said investigators were looking carefully to determine if there is an IS connection.
Attorneys representing Farook's family said Friday that none of his family members had any indication either Farook or his wife held extremist views. They urged the public and media to wait for specific evidence before jumping to conclusions.
Farook and Malik rented a townhome where investigators said they found an arsenal of ammunition and homemade bombs. On Friday morning, the property's owner allowed reporters inside.
Bowdich said the FBI was done with the scene and that analysts were trying to retrieve data from two cellphones found near there that had been crushed in an apparent attempt to destroy the information inside.
"We hope that will take us to their motivation," he said.
Until Friday, federal and local law enforcement officials said terrorism was a possibility but that the violence could have stemmed from a workplace grudge or a combination of motives.
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Farook had no criminal record and neither he nor his wife was under scrutiny by local or federal law enforcement before the attack, authorities said.
Malik, 27, was a Pakistani who grew up in Saudi Arabia and came to the U.S. in 2014 on a fiance visa. Farook, a 28-year-old restaurant health inspector for the county, was born in Chicago to Pakistani parents and raised in Southern California.
Law enforcement officials have long warned that Americans acting in sympathy with Islamic extremists - though not on direct orders - could launch an attack inside the U.S. Using slick propaganda, the Islamic State in particular has urged sympathizers worldwide to commit violence in their countries.
Others have done so. In May, just before he attacked a gathering in Texas of people drawing cartoons of the Prophet Muhammad, a Phoenix man tweeted his hope that Allah would view him as a holy warrior.
Two weeks ago, with Americans on edge over the Islamic State attacks in Paris that left 130 people dead, Comey said that U.S. authorities had no specific or credible intelligence pointing to an attack on American soil.
Since March 2014, 71 people have been charged in the U.S. in connection with supporting ISIS, including 56 this year, according to a recent report from the George Washington University Program on Extremism. Though most are men, "women are taking an increasingly prominent role in the jihadist world," the report said.
It was not immediately clear whether Malik exhibited any support for radical Islamists before she arrived in the U.S. - or, like scores of others arrested by the FBI, became radicalized through online or in-person associations after arriving.
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Friends of the soft-spoken Farook who knew him from his daily prayers at a mosque in San Bernardino said they saw nothing to make them think he was violent. They said Farook reported meeting his future wife online.
To receive her visa, Malik was subjected to a vetting process the U.S. government describes as vigorous. It includes in-person interviews, fingerprints, checks against terrorist watch lists and reviews of her family members, travel history and places where she lived and worked.
Foreigners applying from countries that are home to Islamic extremists - such as Pakistan - undergo additional scrutiny before the State Department and Homeland Security approve their applications.
A history of mass shootings in the United States
Pakistani intelligence officials said Malik moved as a child with her family to Saudi Arabia 25 years ago.
The two officials, who spoke to The Associated Press on condition of anonymity, said that the family is originally from a town in Punjab province and that the father initially moved to Saudi Arabia around three decades ago for work.
Another person close to the Saudi government said Tashfeed Malik did not stay in Saudi Arabia, eventually returning to Pakistan and living in the capital Islamabad, though she returned to Saudi Arabia for visits. The person was not authorized to speak publicly, and did so on condition of anonymity.
Friends in Southern California said they had no idea Farook and Malik were building pipe bombs and stockpiling thousands of rounds of ammunition for their commando-style assault on a gathering of Farook's colleagues from San Bernardino County's health department.
On Friday morning, the owner of the townhome that Farook and Malik rented opened it to reporters. On a living room table was a copy of the Quran. An upstairs bedroom had a crib, boxes of diapers and a computer. The couple had a 6-month-old daughter.
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