After the mass shooting in San Bernardino, Calif., on Dec. 2, that left 14 people dead, the FBI is unearthing more information about who was involved in the attack. Here's what we know about Syed Rizwan Farook, his wife Tashfeen Malik and his neighbor Enrique Marquez. (The Washington Post)

The former neighbor who provided shooter Syed Rizwan Farook with the rifles used in the San Bernardino attacks is now cooperating with officials and has sat down for several interviews, according to senior law enforcement officials.

The FBI is gleaning that the neighbor, Enrique Marquez, was extremely close with Farook. Agents are trying to determine whether the two had discussed and taken actual steps to carry out an attack in 2012 when they became spooked by the arrests of four men in Riverside, Calif., who were involved in a separate plot to kill Americans in Afghanistan, a senior law enforcement official said Wednesday.

The timing of Marquez and Farook’s possible plot is significant because Marquez legally purchased the rifles used in the San Bernardino attack around the same time. Marquez bought one rifle in 2011 and the other before late February in 2012, according to law enforcement officials. The military-grade rifles were semiautomatic AR-15s manufactured by DPMS and Smith & Wesson. The FBI is still investigating whether Marquez sold these rifles to Farook, according to the officials, who also spoke on the condition of anonymity for similar reasons.

Marquez was married to a woman who appears to be a relative of Tatiana Farook, the wife of Syed’s brother Raheel, according to county records. Both Marquez and the bride, Russian-born Mariya Chernykh, list the same home address as Raheel Farook, and Raheel and Tatiana Farook were witnesses to the couple’s marriage.

Soon after the shooting, Marquez checked himself into a mental health facility but has since left and started talking with authorities.

FBI Director James B. Comey said Wednesday that there was an attempt to convert the rifles into fully automatic weapons before the attack.

Farook and his wife — who killed 14 people last week in San Bernardino, Calif. — were discussing jihad at least two years before they opened fire, Comey said.

An undated combination photo of Tashfeen Malik, left, and Syed Farook. (FBI/California Department of Motor Vehicles via AP)

The husband-and-wife duo “were radicalized for quite a long time before their attack,” Comey reiterated during an appearance on Capitol Hill in front of the Senate Judiciary Committee. This follows earlier statements by investigators that the couple had been adherents of a radical strain of Islam long before the massacre.

Farook, a 28-year-old county health inspector, and his Pakistani wife, Tashfeen Malik, 29, had begun communicating online, Comey said. It was during these communications that they began discussing jihadist thoughts, long before Malik traveled to the United States and they got married.

“And online . . . as early as the end of 2013, they were talking to each other about jihad and martyrdom before they became engaged and then married and lived together in the United States,” Comey said during his testimony.

This radicalization appears to predate the rise of the Islamic State, the terrorist group that in 2014 formally declared a caliphate in parts of Iraq and Syria.

Comey said investigators believe the attackers were “inspired by foreign terrorist organizations.”

“We’re working very hard to understand exactly their association and the source of their inspiration,” he said. “We’re also working very hard to understand whether there was anybody else involved with assisting them, with supporting them, with equipping them.”

When asked by Sen. Lindsey O. Graham (R-S.C.), a presidential candidate, if the marriage between Malik and Farook was arranged by a terrorist organization, Comey said he did not know.

“It would be a very important thing to know,” Comey said. He also said he was not aware of any Islamic State cells operating in the United States.

Comey was critical of anti-Muslim rhetoric, saying that it is not helpful when law enforcement officials are trying to work with communities in the United States to combat terrorism. He said that for the Islamic State and other terrorist organizations, it is part of their strategy to convince Muslims that the United States is hostile to them.

The Republican presidential front-runner, Donald Trump, drew international criticism this week for his call to ban all Muslims from the United States following the San Bernardino shooting and the attacks in Paris last month.

 

Farook brought his wife to the United States on a fiancee visa in July 2014. Relatively little is known about Malik, who was born in Pakistan but spent at least some time in Saudi Arabia, where her father relocated more than two decades ago.

It remains unclear how much time she spent in Saudi Arabia, but she is known to have studied in Pakistan to become a pharmacist.

Julie Tate and Alice Crites in Washington contributed to this report.

[This story has been updated. First published: 10:56 a.m.]