A federal source today confirmed to NPR that the female shooter in San Bernardino pledged support for the leader of ISIS on social media around the time of Wednesday's rampage, though there is still no evidence that she and her husband were actually members of, or directed by, ISIS.
Investigators still don't know the motive for the attacks, but one thing they do know is that the shooters had four weapons: two handguns and two AR-15 rifles. All had been purchased legally in California.
Here & Now's Jeremy Hobson talks with Alex Yablon, a reporter with the nonprofit reporting website The Trace, which is dedicated to expanding coverage of gun issues in the U.S., about the weapons that were used in this week's shooting, and how they compare to weapons used in other recent mass shootings.
This segment aired on December 4, 2015.