SAN BERNARDINO -- Investigators think that as the San Bernardino, California, massacre was happening, female shooter Tashfeen Malik posted a pledge of allegiance to ISIS leader Abu Bakr al-Baghdadi on Facebook, three U.S. officials familiar with the investigation told CNN.
Malik's post was made on an account with a different name, one U.S. official said. The officials did not explain how they knew Malik made the post.
A law enforcement official said it appeared that Wednesday's mass shooting -- which left 14 people dead and 21 wounded before the two attackers, Malik and her husband, Syed Rizwan Farook, were killed in a shootout with police -- may have been inspired by ISIS.
But none of the officials said that ISIS directed or ordered the attack. ISIS has called for people worldwide to launch attacks in its name, but isn't known to have claimed credit for what happened in San Bernardino.
At a Friday press conference, FBI official David Bowdich said authorities are officially investigating the massacre as "an act of terrorism."
Bowdich said a number of pieces of evidence pushed authorities to launch a terrorism investigation. He noted some phone conversations between at least one of the San Bernardino shooters and other people are being investigated by federal officials.
No one has been arrested in connection with the massacre.
"This is looking more and more like self-radicalization," a law enforcement official said.
Another official said authorities haven't ruled out that others may have influenced this radical view. In addition, the law enforcement source said investigators have a greater focus on whether the shooting occurred after a workplace issue with religion.
Farook's relatives had no idea why the couple burst into a holiday luncheon for Farook's co-workers and viciously opened fire, family lawyers said. Nor did they have an idea the couple had a makeshift bomb lab in the apartment they shared with their 6-month-old daughter and Farook's mother. Nor did they know either of them were radicalized.
"It just doesn't make sense for these two to be able to act like some kind of Bonnie and Clyde or something," Farook family attorney David S. Chesley told CNN's Chris Cuomo. "It's just ridiculous. It doesn't add up."
Officials: Farook talked to person investigated for terror
Neither Farook nor his wife had gotten into trouble with the law, according to police. And neither was on any list of potentially radicalized people.
But it's not known what connections Malik, who was born and raised in Pakistan and moved to Saudi Arabia around the age of 19, had with any terrorists or groups before the San Bernardino massacre.
Investigators are exploring Farook's communications with at least one person who was being investigated for possible terror connections. Some were by phone, some on social media.
"These appear to be soft connections," an official said, meaning they were not frequent contacts. Farook's last communication with the contacts was months ago.
The FBI wants to interview some of them to learn more about their conversations with Farook.
A federal official said Farook has "overseas communications and associations," but it's not yet clear how relevant they are to the shootings. "We don't know yet what they mean," the official said.
Family lawyer Mohammad Abuershaid said that Farook traveled twice to Saudi Arabia -- first in 2013 for the Hajj, the annual pilgrimage to Mecca that Muslims are required to take at least once in their lifetime, then again to marry Malik, whom he'd met through an online dating service.
FBI official David Bowdich said that he went to Pakistan as well, though Abuershaid denied that.
Farook and Malik "kept to themselves" in California, Abuershaid said. But the interactions they did have with relatives 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, according to the lawyer.
"There was nothing to show that (Malik) was extreme at all," Abuershaid said. "(And Farook) was a normal guy, in every sense of the word."AlertMe