A U.S. law enforcement official says the wife of the couple blamed in the deadly California shootings pledged allegiance to the Islamic State group and the terror group's leader on Facebook using an alias then deleted the messages before the attacks.
Specifics details about Tashfeen Malik's postings weren't disclosed Friday by the law enforcement official, who spoke on condition of anonymity because this person was not allowed to discuss an ongoing investigation.
The remarkable disclosure about Malik's online activities provided the first significant details suggesting a motive for her participation with her husband, Syed Farook, in the shootings that killed 14 people and injured 21.
Malik was a Pakistani woman who came to the U.S. in 2014 on a fiancee visa before Farook married her in California.
The brother-in-law of one of the attackers in San Bernardino, California, says Syed Farook was a 'bad person,' but he wasn't radical.
Farhan Khan also told NBC News he is beginning the legal process to adopt Farook's 6-month-old daughter, who was dropped off with relatives Wednesday morning before the shooting that left 14 dead. Farook and his wife, Tashfeen Malik, were killed in a shootout with police following their deadly rampage.
In excerpts of the interview released Friday, Khan expressed disbelief that Farook would leave behind his infant girl and said he was angry with Farook for the attack.