Exactly one year ago, a mass-shooting in the city of San Bernardino took 14 lives and left 22 wounded.
Armed with high-powered rifles, the suspects, husband and wife Syed Farook and Tashfeen Malik opened fire at a holiday party at a building called the Inland Regional Center and then fled the scene.
The pair were killed hours later in a shootout with police.
In the days that followed, FBI Director James Comey said that the couple showed signs of extremism and "...their joint commitment to jihad [and] martyrdom" in online conversations before meeting face-to-face.
So what has law enforcement learned since the attacks? And is the country safer today than it was one year ago?
Take Two put that question to Erroll Southers, Director of Homegrown Violent Extremism Studies at USC.
There have been several acts of terror around the world from Africa and the Middle East to the truck attack on Bastille day in France. We can't forget the Orlando nightclub shooting in June that left 49 dead and has been characterized as terrorism and a hate crime. As this year ends, how would you describe this past year?
This past year has clearly demonstrated the importance of countries focusing on what we call homegrown terrorism. The attacks in the United States, the attacks in France, have largely been perpetrated by individuals who were either born in those countries or naturalized citizens.
We've come to the realization now that, as we have concerns about immigrants and refugees, a larger concern has to rest with those people who are native to the country.
How are local law enforcement agencies and the federal government working together to investigate and battle homegrown extremism, and how has that changed in the past year?
What's changed in the last year are tremendous efforts of community outreach. Law enforcement agencies and communities have had to partner even more aggressively now because we have a threat that is mostly hidden within communities and families that are hesitant to report because it may be someone that they know or maybe an immediate family member.
Would you say progress has been made when it comes to preventing things like what we saw in San Bernardino last year?
The challenge comes, not so much with regards to agencies reaching out, but it's the way in which it's done.
If you reach out to a community based on their race, based on their religion or ethnicity, there's pushback because, in most cases, those communities might ask, 'well, why are you coming to me? I'm not a terrorist. Why would you talk to me about that?' So, it's a very delicate balance of building a relationship not on countering violent extremism; it's building a relationship based more on public safety and then getting to that point where you can have the conversations about the threat of homegrown terrorism.
Is the United States safer than it was on December 2nd of 2015?
I think we are safer right now than we were last year at this time. I think we are demonstrably safer since 9/11. Agencies have, on a local, state and federal level, joined in sharing information better and collecting intelligence better. They've become a lot better about informing the public.
So we are safer now, and — rest assured — every time there's a thwarted plot, it's because some agencies have worked together to see to it that it doesn't happen.
Press the blue play button above to hear the full interview.
(Answers have been edited for clarity and length.)
(Correction: A previous version of this post identified the Inland Regional Center as a government building. The post has been updated.)