STEVE INSKEEP, HOST:
When police found the home of two shooting suspects in San Bernardino, Calif., they found thousands of rounds of ammunition. They also found dozens of pipe bombs. And now those are among the clues police have as they ask what the two suspects - now dead - might have been thinking. NPR counterterrorism correspondent Dina Temple-Raston is on the line. Dina, what are you learning?
DINA TEMPLE-RASTON, BYLINE: Well, police are investigating this as a terrorist act, but they're far from concluding that this was a terrorist act. You know, these kinds of situations also usually fall into a pattern, and this one isn't falling into a regular pattern. Just to remind you, there are two main suspects - Syed Rizwan Farook and Tashfeen Malik. They were married, they were both in their 20s, they had a daughter who was 6 months old, and there was some question right after the attack whether there was a third person. Now investigators don't think there was a third person. And there are a couple of details that they've discovered that are making authorities believe this is something beyond just a case of workplace violence. Authorities had been looking at Farook's computer and his electronic history - you know, cell phones, thumb drives, that sort of thing. And sources tell NPR that he started deleting material that might've helped investigators days before the attack happened. And then, as you mentioned, there's this cache of ammunition - literally thousands of rounds. And then if you put that together with deleting this information, that leads them to believe that this was planned and not just something that - you know, like a holiday party that set him off.
INSKEEP: Does the surviving information contain any clues suggesting a connection to some outside group like al-Qaida or ISIS?
TEMPLE-RASTON: Well, there is this question about whether pipe bombs that were built came from al-Qaida's Inspire magazine. But that's a bit of a red herring, as the bomb recipes in that magazine are fairly generic. And in fact, if you Google make a bomb, the articles in that magazine are among the first to come up. I mean, what's unusual is - a husband and wife attack team is really unusual. This may be the first time that we've ever seen a new mother take part in an attack. And it's also interesting that there haven't been any witnesses who've mentioned hearing the shooters shout Allahu Akbar - you know, God is great - before the shooting began. I mean, that's often shouted to send a message from Islamic terrorists. But that - nothing like that was said that we know of. There also hasn't been a martyrdom video or some sort of message that we know of. You usually see that in these kinds of cases. So this is all out of the normal pattern.
INSKEEP: In the 30 seconds or so that we have, Dina, what questions are investigators asking now?
TEMPLE-RASTON: Well, they're considering that maybe this was an attack that was inspired by a combination of things. Maybe there was a workplace problem. Maybe Farouk had experienced some sort of discrimination. San Bernardino has a bit of a white supremacist gang problems - that could be one avenue that they're pursuing. He also found his wife online, and in his online questionnaire he said that he was a mix between Eastern and Western ideas. So they're pursuing that it's possible that he had some identity issues, and that motivated this too.
INSKEEP: OK, Dina, thanks very much.
TEMPLE-RASTON: You're welcome.
INSKEEP: That's Dina Temple-Raston who covers counterterrorism for NPR.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.