Federal law enforcement officials say the woman who helped carry out the Dec. 2 mass shooting in San Bernardino, California, had sworn a pledge of allegiance to ISIS on Facebook before dying in a shoot-out with law enforcement.
Female shooter Tashfeen Malik reportedly used a Facebook account under another name, according to CNN, and investigators say the post was put up while the massacre was taking place.
A law enforcement official familiar with the investigation said it appeared as if Malik and her husband, Syed Rizwan Farook, who killed 14 people and injured another 21 of Farook's workplace colleagues at a holiday luncheon, had possibly been inspired by ISIS.
Law enforcement officials currently believe the couple acted on their own accord, rather than being under direct orders from ISIS.
“At this point, we believe they were more self-radicalized and inspired by the group than actually told to do the shooting,” one official told The New York Times.
Investigators are also looking into whether a workplace issue involving religion might have influenced the couple. Nicholas Thalasinos, a Jewish colleague of Farook who died in the shooting, reportedly liked to talk about politics and religion. A friend of Thalasinos told CNN he once had a "heated, passionate" discussion with Farook.
Ultimately, investigators are still looking for answers. Malik's past is not well-known to law enforcement; officials know that she was born in Pakistan, lived in Saudi Arabia relatively recently, and reportedly met Farook through an online dating site, The Times reports.
The FBI was also able to deduce that Farook had been in contact with five individuals whom the FBI was investigating for possible involvement in terrorist activities, although the significance of these contacts is not known.
2015 has seen the FBI refocus its efforts on self-radicalized Americans, as ISIS has been trying to influence people in foreign countries to do the group's bidding in their home countries rather than urging them to travel to Syria.
“We’ve especially focused on the portfolio of people we’re investigating for the potential of being homegrown violent extremists; that is, people consuming the propaganda," FBI Director James Comey said during a press conference in November, according to The Times. "So those investigations are designed to figure out where are they on the spectrum from consuming to acting.”