The two California shooters had radicalised even before they met and talked about jihad and martyrdom two years ago, in 2013, the FBI has said. They married in 2014.
US investigators are also looking at a childhood friend of Syed Rizwan Farook, who bought the two military stye assault rifles the killers used in the San Bernardino shooting.
Also on the radar of the investigators is a loan of $28,000 Farook took in days ahead of the shooting. The money was advanced by an online loaning firm.
The FBI had earlier said the couple, Farook and his Pakistani wife Tashfeen Malik, had been radicalised for “quite some time”, overruling the possibility of one influencing the other.
FBI director James Comey told senators at a hearing Wednesday Farook and Malik had radicalized much before they met online, and Malik had held these views before she came to the US.
“Our investigation to date shows that they were radicalized before they started courting or dating each other online,” Comey said, “and as early as the end of 2013 were talking to each other about jihad and martyrdom before they became engaged and married and were living in the US.”
The investigators are now trying to find out if the couple had anyone else “involved in assisting, equipping or helping them”, Comey said, adding, “And did they have other plans?”
The couple had posted a pledge of allegiance on Facebook to Islamic State’s Abu Bakr al-Baghdadi during the attack on December 2 and the terrorist outfit called them supporter later.
But IS did not claim responsibility for it as it had for the Paris attacks, and investigators have found nothing yet to connect the San Bernardino shooting to instruction from abroad.
Investigators are also looking at the childhood friend Enrique Marquez, who bought these rifles in 2011 and 2012, and did he gift them to Farook and why.