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We are learning more today about the shooters responsible for last week's attack in San Bernardino. Speaking on Capitol Hill today, FBI Director James Comey said the husband and wife who shot and killed 14 people both radicalized years before their courtship. And he said they appear to have been inspired in part by the Islamic State. NPR justice correspondent Carrie Johnson reports.
CARRIE JOHNSON, BYLINE: James Comey told the Senate Judiciary Committee the FBI is confronting a staggering array of threats. But he spent about three hours on Capitol Hill today talking about one case in particular, the Bureau's urgent and ongoing investigation into the motives of two shooters last week in San Bernardino, Calif.
JAMES COMEY: We're working very hard to understand exactly their association and the source of their inspiration. We're also working very hard to understand whether there was anybody else involved with assisting them, with supporting them, with equipping them. And we're working very, very hard to understand did they have other plans, either for that day or earlier?
JOHNSON: The FBI director says Syed Farook and Tashfeen Malik had been talking about jihad and martyrdom online in late 2013. That's long before their marriage and her arrival into the U.S. on what's called a fiancee visa. Senator Lindsey Graham, a Republican from South Carolina, zeroed in on the circumstances of the marriage.
LINDSEY GRAHAM: Is there any evidence that this marriage was arranged by a terrorist organization or terrorist operative, or was it just a meeting on the Internet?
COMEY: I don't know the answer to that yet.
GRAHAM: Do you agree with me that if it was arranged by a terrorist operative of organized, that is a game changer?
COMEY: It would be a very, very important thing to know.
JOHNSON: Senator Charles Schumer, a Democrat from New York, said he can't understand how the shooters operated under the radar of the FBI for so long.
CHARLES SCHUMER: Here we have somebody who was talking about jihad - two people - for a couple of years, and I think most Americans have the assumption that we're on top of things like this.
JOHNSON: The FBI director said his agents could only monitor those kinds of electronic footprints if they got a valid tip about the shooters. He didn't answer another question about whether the FBI had missed clues the couple in San Bernardino was communicating with terrorist suspects overseas already on the radar of law enforcement.
COMEY: To find homegrown violent extremists, to find those that are radicalizing and being inspired by these terrorist groups is a very hard thing.
JOHNSON: Comey said he needs the help of people in the community including the Muslim-American community to intervene before someone moves toward violence. And under prodding from senators, he said campaign rhetoric that's alienating those communities is no help to protecting national security. The FBI also promised to look into hateful threats against Muslims here following attacks in Paris and San Bernardino.
COMEY: And we want people to know if you think someone is terrorizing or threatening you based on your national origin or your religion, please tell us so that we can investigate that. We're all in this together.
JOHNSON: For now, Comey said he's not aware the Islamic State, which he calls ISIL, has smuggled operatives onto American soil.
COMEY: We have not seen ISIL cells or networks in the United States. So far as we can tell, they have not succeeded in penetrating our borders with their operatives. That's an aspiration of theirs. We've got to worry about it all day every day.
JOHNSON: Comey said he continues to worry about terrorists using encryption to evade detection. So far, there's no evidence that California shooters used those tools, but the FBI director said one of the men in an unsuccessful attack in Garland, Texas this year exchanged 109 messages with a known terrorist overseas. And he said because of encryption, he still doesn't know what those messages say. Carrie Johnson, NPR News, Washington. Transcript provided by NPR, Copyright NPR.