The decision comes amid reports that one of the shooters, Tashfeen Malik, had pledged allegiance to Daesh, also known as ISIL/The Islamic State. Earlier reports also indicated that her husband and accomplice, Syed Rizwan Farook, had been in contact with suspected terrorists through social media.
There is no evidence to suggest that they were directed to carry out the attack by Daesh, but Malik and Farook may have been self-radicalized.
An FBI official said there was "certainly a possibility" that the shooters were planning a second attack, according to Reuters. The FBI also stressed that they are not aware of any terror threats to the United States at this time.
An FBI official has also told MSNBC that they are currently investigating a person of interest who may have legally purchased and provided to Farook the rifles used in the attack.
Malik and Farook opened fire on the conference room of a developmental disabilities center on Wednesday, killing 14 people and injuring another 21. The suspects also left behind what police believe may have been explosives. They were killed during a shootout with police hours later.
A search of the couple's home found large stockpiles of ammunition and explosive material. Over 4,500 rounds of ammunition were discovered, as well as 12 pipe bombs.
