FBI investigating whether Farook's mother knew about his criminal activities

“Obviously it’s something that we’re looking at very, very closely,” Lynch told NBC’s “Meet the Press,” when asked about what the woman may or may have not known before the massacre.

Law enforcement officials have said that Rafia Farook lived in the same house in Redlands, California where her son, Syed Farook, and his wife, Tashfeen Malik, were building at least 15 pipe bombs and stockpiling thousands of rounds of ammunition.