MS. DIANE REHMThanks for joining us. I'm Diane Rehm. Yesterday, in San Bernardino, California, 14 people were killed and 17 injured. Later in the hour, we talk about reporting from the Columbia University journalism school, critical of Exxon's climate policy, but first, we turn to San Bernardino for the latest and what we know.

MS. DIANE REHMHere with me in the studio, Ron Elving of NPR, joining us by phone from an office in Washington, D.C., Adam Winkler, professor of law at UCLA and by phone from Pasadena, California, Ben Bergman, senior reporter at KPCC. I'm sure many of you will want to join us. However, in this shortened portion of the program, we will not be taking phone calls. I look forward to speaking with you a bit later in the hour.

MS. DIANE REHMAnd welcome to all of you.

MR. RON ELVINGGood to be with you.

MR. BEN BERGMANHi.

MR. ADAM WINKLERGood to be here.

REHMBen, if I could start with you, what has actually been confirmed thus far? I know the brother-in-law has spoken out in total shock and surprise. What do we know about that third person who was detained, but may not be connected to the shooting?

BERGMANWe know very little about the third person. Authorities, initially, said there were three shooters yesterday and then they backed away from that last night, saying they were pretty confident there were only two shooters, Syed Farook and Tashfeen Malik, who had been at this workplace gathering, some kind of sort of holiday gathering at this Inland Regional Center, which is a huge center in San Bernardino that serves the developmentally disabled.

BERGMANAnd then, Farook returned to this gathering and then opened fire yesterday, but we really don't know about that third person, which had been seen in the vicinity where this confrontation happened later in the afternoon, which killed Farook and Malik. Authorities detained this third person, but we don't really know much more about that person.

REHMDo we know anything about the argument or the confrontation that apparently took place at the party or the gathering or the luncheon or whatever it was?

BERGMANWe don't. We just know there was a dispute and that Farook left angry and then came back and opened fire. And it doesn't really make sense because it's sort of this -- a workplace dispute, which we've seen before, and someone very upset. But the idea then, that he would come back and be so prepared, is how authorities described it, and know exactly what he wanted to do and have explosive devices, pipe bombs, but also very heavy artillery, in a sense, ready to go and an escape plan belies the notion that this was not something spontaneous.

REHMThey had dropped off their six-month-old baby before the rampage took place. How were they dressed? There's been some indication that they were in battle gear.

BERGMANYeah. They were described to be, by witnesses, en mass, they were described to be with bulletproof vests. So, again, another notion that this was just not a random act that -- of workplace violence.

REHMAdam Winkler, we know now that the guns were purchased legally?

WINKLERThat's right. That's what we've -- the initial reports are, that at least two of the firearms were purchased legally. The other two, apparently, are still being investigated to determine what their origin is. And, of course, California does have very restrictive gun control laws, at least relative to other states in the nation. So we don’t know exactly what laws could've been in place that could've avoided this kind of mass shooting, but in any case, we should be focusing on trying to reduce the daily death toll from guns, in any event.

WINKLERMass shootings are exceptional in that they are becoming kind of commonplace in America. But they can really happen everywhere whenever you have a country that's awash in guns like ours.

REHMHowever, you have said that this latest mass shooting is more serious than others. Why?

WINKLERWell, it's more serious in one sense, I mean, there's a lot of victims, the most people who have been victim of a mass shooting since Newtown. It's also a very unusual case. Nearly all the mass shootings we've had in the last 15 years have involved solo perpetrators. There's only, I believe, two mass shootings in the past where you had more than one shooter.

WINKLERAlso, they're almost always men and here we have a woman involved, too. And usually mass shooters are people who we think of as disturbed and who have nothing really to live for. This couple had a young daughter. It's very odd that you would see people with so much to live for, apparently, good jobs, good families, committing some kind of crime like this.

REHMAnd turning to you, Ron Elving, do you think that this act of killing will change the politics of guns in this country?

ELVINGThis is a wrenching moment at which to respond that question. As it was after Newtown, as it is after ever shooting and let's not forget, we're just a few days removed from the Colorado Springs shooting, Robert Dear is being held in custody as being charged in those shootings in which a number of people were shot over hours, many law enforcement officers who came in response to the shooter. This is the second really wrenching incident and that is really the word that keeps coming back to my mind.

ELVINGAnd yet, we have to say that after previous massacres -- I think that word is well used, we have not seen a fundamental change in our national politics with respect to guns. About a quarter of a century ago, in the early 1990s after a horrific schoolyard shooting in California, Senator Diane Feinstein who was a senator then, is a senator from California today, got the Congress, got the Senate behind a bill in the early years of the Clinton administration that would ban assault weapons.

ELVINGWe also got the Brady bill, but we got a completely different mood in the country or so we thought, in the early 1990s. But after a big turnaround election in 1994, delivered majorities in the House and Senate to the Republican party, the enthusiasm for that kind of legislation waned and the assault ban lapsed. It expired. And the perception has been, among political professionals, that the 1994 election and then again the 2000 lost by Al Gore were both evidence that by being for stronger gun control, the Democrats were slitting their throats politically.

ELVINGAnd that notion has survived some horrific incidents, including the ones we have seen in the last few years and, of course, Newtown. Now, at Newtown, we are talking about 6 adults and 20 children and it seemed, after Newtown, that everything would have to change. And briefly support for stronger gun control went up about 15 percentage points in national polls. Thereafter, it drifted back downward and we are where we are today.

ELVINGThere was, in April of 2013, a bill before the Senate got 54 votes for universal background checks. That was sponsored by two conservative members, one Republican, Pat Toomey from Pennsylvania, one Democrat, Joe Manchin from West Virginia, and they fell six votes shy of the 60 they needed.

REHMAdam Winkler, what is your view? Is anything going to change?

WINKLERWell, I think that the gun debate and gun politics have changed, actually, a lot since 2012 and the Newtown shootings. I think everyone's frustrated 'cause we haven't seen new federal legislation and it's true. We are stalemated at the federal level. However, we've seen new signs of life in the gun control movement. There's a lot of political mobilization on the pro-gun control side, where historically there was very little.

WINKLERThere's a lot of money going into gun control, gun races on the gun control side and we're seeing a more level playing field against the NRA in electoral expenditures and political mobilization. And while we've seen nothing in the federal level, we've seen new state legislation in about a dozen states, including Colorado and California where these last two shootings have occurred.

REHMAnd if I can just point out, Senator Harry Reid has just tweeted, we're going to force the Senate to vote today on amendments to do something to stop gun violence. What might that mean, Ron Elving?

ELVINGWell, as it happens, before the Senate today is a reconciliation bill. It is full of many, many, many issues. It is something that can be passed with 51 votes as opposed to 60 and so we're going to see many efforts. There's going to be an effort, among other things, to repeal Obamacare or at least to say it's repealing Obamacare. And that's going to also be roiling the consideration of the reconciliation bill.

ELVINGLet me hasten to say that among those who do feel that we need stronger gun laws, there has been a reawakening of effort and spirit since the shootings at Newtown in the last several years. And those people have tried very hard to organize. We know that Michael Bloomberg, the mayor of New York, has put a lot of money into a number of races with mixed results and we know that there has been more money on the gun control side in many of these contests.

ELVINGBut where we remain at the federal level is important because whatever the states do, whatever the states do and they are empowered to do much on their own, it is difficult to enforce if people can cross state lines as easily as they do with guns so that one jurisdiction with tough gun laws is subject to the lax gun laws in another jurisdiction.

REHMSo Adam Winkler, in 10 seconds or less, what might Harry Reid be able to get through?

WINKLERWell, the biggest proposal they're focusing on, as far as I understand, is a proposal to add people on the terrorist watch list to the prohibited gun purchaser list. I don't know if that's gonna go through or if that's gonna be the subject of what Harry Reid is going to propose, but there's been a lot of talk in Washington about that proposal.

REHMAdam Winkler, professor of law at UCLA, author of "Gun Fight: The Battle Over The Right To Bear Arms In America." Ben Bergman of KPCC, Ron Elving of NPR. Thank you all.