FBI Director James Comey told a Senate hearing Wednesday that Syed Farook and Tashfeen Malik were radicalized and dedicated to jihad long before they started dating online.
As early as the end of 2013 — before the rise of ISIS — they were talking to each other about jihad and martyrdom before they talked about her coming to the United States, Comey told members of the Senate Judiciary Committee.
Malik was later granted a K-1 fiance visa to join her would-be husband in California.
Related: San Bernardino Shooter Used 'Fiancee Visa' to Enter U.S.: Sources
“Our investigation to date shows that they were radicalized before they started courting or dating each other online,” Comey said.
Comey described the couple as "homegrown violent extremists" who were inspired by foreign terror groups.
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FBI officials had previously said that the couple had been radicalized for "quite some time," but the disclosure Wednesday was the most specific yet about the timeline of their relationship and progression toward extremism.
Relatives have described Farook and Malik as a happy couple who gave no outward sign of being Islamic fanatics. They even registered at Target before their baby daughter was born.
Related: San Bernardino Shooters Practiced for Attack a Year in Advance
But the couple was living a double life.
Farook and Malik spent at least a year preparing for their terror attack, NBC News has learned, practicing at a local gun range and making financial plans for their family after their deaths. And the husband may have discussed an attack as many as three years ago, law enforcement sources said Tuesday.
Related: Tashfeen Malik, Mother in San Bernardino Massacre, Pledged Allegiance to ISIS Leader: Sources
Two sources said Farook and Malik had practiced their shooting skills at a Riverside, California-area gun range for a year or more before last Wednesday's attack on a holiday office party. They killed 14 people and wounded 21 more with firearms at the Inland Regional Center in San Bernardino.
Malik pledged allegiance to the leader of ISIS just before she and her husband carried out the San Bernardino massacre, law enforcement sources told NBC News.
Related: San Bernardino Shooter Tashfeen Malik Didn't Stand Out Back in Pakistan
On Wednesday, Sen. Diane Feinstein, D-Calif., also criticized the FBI for turning Farook's home back to the landlord, who allowed reporters to get in last Friday.
FBI Director James Comey told her agents spent more than 24 hours in the house, gathering evidence, recording items, and then following the law by posting an inventory of what was taking and turning it back to the landlord.
"I can't explain why the landlord allowed people to go in," Comey said. "What happened next was strange." But he said the investigators determined they were done, and that there was nothing else to be done there.
"Oh, boy," Feinstein said. "From an intelligence point of view, I could see things in an investigation that you might want to come back to. That doesn't seem to me to be smart."