ISIS has now claimed the suspected shooters in San Bernardino as "supporters" of the militant group, though that doesn't mean the group had any hand in orchestrating Wednesday's attack.
During a broadcast on al-Bayan Radio, ISIS praised the attack that killed 14 people as carried out by two supporters and said "We pray to God to accept them as martyrs." But it stopped short of claiming responsibility.
So far, officials haven't given any indication the married couple Syed Farook or Tashfeen Malik had direct contact with ISIS or any other terror group.
"Based on the information and the facts as we know them, we are now investigating these horrific acts as an act of terrorism," said the assistant director of the FBI's Los Angeles office.
See inside the San Bernardino shooting suspects' home:
Several media outlets have confirmed through law enforcement Malik posted a statement to Facebook under a false name in support of ISIS leader Abu Bakr al-Baghdadi shortly before Wednesday's attack.
ISIS called for supporters to carry out attacks on the West earlier this year, and law enforcement sources indicate it's far more likely the couple was self-radicalized and inspired by ISIS.
More from AOL.com:
Ted Cruz: 'You stop bad guys by using our guns'
British bombers hit oil field targets in Syria for second time
'Affluenza' teen who was spared prison after killing 4 is seen partying in video