Authorities provided an update Monday afternoon on their investigation into the San Bernardino, California mass shooting.
Federal agents say it appears that both people involved in the shooting, Syed Farook and his wife Tashfeen Malik, were radicalized before the attack at a holiday party that killed 14 people and injured 21 others.
The FBI says it has found evidence of pre-planning in advance of the deadly shooting. Agents are vowing to get to the bottom of the attack, and find any other people who may have been involved in the crime. The FBI says to this point, there is no evidence that the attack was directed by persons or organizations from overseas.
The ATF says it has traced the five weapons that were involved in the shooting. Agents say those weapons were purchased in California starting in 2007. The weapons are now being tested at the FBI laboratory for forensic evidence. Syed Farook purchased two of the firearms himself, according to investigators.
Malik and Farook were killed in a shootout with police hours after they opened fire with assault rifles on a gathering of Farook's colleagues last Wednesday.
The FBI said Friday that it is investigating the shooting as an act of terrorism. If the massacre was inspired by Islamic extremism, it would be the deadliest such attack on U.S. soil since Sept. 11, 2001.