Tashfeen Malik, who assisted her husband carry out Wednesday’s mass shooting in San Bernardino, had sworn allegiance to ISIS.
Officials announced that the Pakistan-born 27-year-old pledged loyalty to the extremist organisation’s leader, Abu Bakr al-Baghdadi.
She made the declaration on Facebook using a different name.
With her husband, 28-year-old Syed Farook, she massacred 14 of his colleagues and injured another 21 during a holiday party at a social services centre.
Farook, an Illinois-born restaurant inspector, had been in touch with Islamic extremists on social media, say US intelligence officials.
Police said they found a dozen more pipe bombs in a bag and nearly 5,000 rounds of ammunition at the killers’ home.
Their family lawyer spoke out and said Farook and Malik “kept to themselves,” Abuershaid said. But the interactions they did have didn’t hint at any significant changes in their thinking or demeanor, any turn to Islamist extremism, or any sign they were plotting a mass killing, the lawyer said.
Police said they found a dozen more pipe bombs in a bag and nearly 5,000 rounds of ammunition at the killers’ home.
The FBI have been scouring the couple’s mobile phones and a computer hard drive found at their home in Redlands, California.
Images of the assault rifles and guns they used have also been released, as well as a new photo of their truck peppered with bullet holes.
Farook’s brother-in-law, Farhan Khan, has told NBC News he was a “bad person”, but he wasn’t radical.
The killers dropped off their six-month-old daughter with relatives on Wednesday morning before the massacre.
Read More: San Bernardino shooting: Attacker pledged allegiance to ISIS, officials say
