SAN BERNARDINO, Calif. – Federal authorities raced Saturday to piece together clues about the California couple who carried out the deadliest terrorist assault on U.S. soil since 9/11, as President Barack Obama warned of the dangers of attackers who become radicalized at home.
As part of the expanding investigation, FBI officials launched a raid early Saturday at the house of a man thought to have bought two rifles used in the attack. The FBI is working to determine whether the man had any knowledge of the plot, in which 14 people were killed and 21 wounded at a holiday party in San Bernardino.
Investigators are pursuing leads as far away as Pakistan and Saudi Arabia that they hope will explain how Tashfeen Malik, a Pakistani woman who immigrated to the U.S. in 2014, and her husband, Syed Rizwan Farook, an Illinois-born health inspector, pulled together what appeared to be an elaborate attack plan.
"We’re working to get a full picture of their motives – why they committed these revolting acts," Obama said in his weekly address. "We’re going to get to the bottom of this."
The incomplete picture of the attackers and their motives reflects the difficulty of detecting and preventing attacks by individuals with few or no substantial connections to militant organizations overseas.
An audio message broadcast by the Islamic State on Saturday said that two "supporters" had executed the San Bernardino attack, but it stopped short of saying the pair were members of the extremist group, which controls parts of Iraq and Syria.
The group has not claimed responsibility for Wednesday’s bloodshed, as it did for other recent attacks, including the coordinated assaults that killed 130 people in Paris.
While officials said they have not uncovered evidence to suggest that Farook, 28, and Malik, 29, were part of a larger militant organization, Malik appears to have admired the Islamic State. About the time of the attacks, Malik, who gave birth to the couple’s child in May, pledged allegiance on Facebook to the group’s leader, Abu Bakr al-Baghdadi.
The Islamic State, under pressure after more than a year of U.S. and allied airstrikes, has urged its followers to launch attacks in the West.
U.S. authorities are now seeking to determine how the couple, who were living with Farook’s mother in a modest two-story townhouse in Redlands, a city near San Bernardino, prepared for the attack. Investigators discovered a huge arsenal, including a dozen pipe bombs and thousands of rounds of ammunition.
Early Saturday, law enforcement authorities raided a home next door to one where the Farook family once lived in Riverside, California. According to a law enforcement official, the raid targeted Enrique Marquez, who is believed to have bought the two military-grade rifles used in the attack.
Both weapons were modified in a way that allowed them to be used with greater lethality, suggesting extensive planning for the attack.
Marquez is believed to have checked himself into a nearby mental health facility.
The official, who spoke on condition of anonymity, said Marquez is believed to have had contacts with individuals in Los Angeles who are already being tracked by the FBI. Officials intend to question Marquez about those links, but it was not immediately clear whether he had already been interviewed by the FBI.
Law enforcement officials are now scouring social media for clues about the attackers’ intentions and are also examining evidence recovered after the attack, including several mobile phones that appeared to have been intentionally damaged to prevent their exploitation.
Obama received an update on the investigation Saturday morning from FBI Director James B. Comey, along with Attorney General Loretta E. Lynch and Homeland Security Secretary Jeh Johnson, the White House said in a statement.
In his weekly address, Obama said the attacks, if motivated by radicalization, "would underscore a threat we’ve been focused on for years – the danger of people succumbing to violent extremist ideologies."
Obama is expected to discuss the San Bernardino investigation and other terror threats from groups such as the Islamic State in an address from the Oval Office on Sunday evening.
Three days after the attack, officials were not yet certain whether Malik or Farook was an instigator of the attack, which has triggered fears among American Muslims about being characterized as potential militants.
But a more clear picture is emerging of Malik, who was born to a prosperous family in Pakistan and earned a degree in pharmacy there. Those who knew her said she grew more conservative over time.
After her arrival in the United States in the summer of 2014, Malik avoided being in the room with male relatives. Because she wore a face covering used by some other Muslims, even her brother-in-law had never seen her face.
Malik also spent years living in Saudi Arabia, where women are, to a large extent, secluded from public life. Saudi officials have said she was not on any security watch list.
Law enforcement officials now think that Farook – who, like many of those killed, worked as a county health inspector – was the among the first to arrive at Wednesday’s gathering at the Inland Regional Center in San Bernardino. That suggests he may have been scoping out the facility. It also could pour water on suggestions that the attack was a workplace dispute triggered by a quarrel.