The wife of Orlando nightclub gunman Omar Mateen was arrested by the FBI on Monday in connection to the mass shooting, officials said.
Noor Salman was taken into custody in California, where her family lives, but the case is filed in Florida, where her husband massacred 49 people at the Pulse nightclub in June.
"I can confirm the arrest did occur," Attorney General Loretta Lynch said on MSNBC.
"This is a matter that we continue to take very seriously," she said. "We said from the beginning we were going to look at every aspect of this case, every aspect of this shooter's life — to determine not just why did he take these actions, but who else knew about them, was anyone else involved, is there any other accountability that needs to be had here in this case."
Orlando Police Chief John Mina disclosed the charges — obstruction of justice and aiding and abetting by providing material support to a terrorist organization — in a tweet.
"Nothing can erase the pain we all feel about the senseless and brutal murders of 49 of our neighbors, friends, family members and loved ones," Mina said. "But today, there is some relief in knowing that someone will be held accountable for that horrific crime."
Authorities said early on in the investigation that they were considering filing criminal charges against Salman if it was shown that she knew what her husband was planning and did nothing.
Salman, who was with her husband when he bought ammunition and exchanged texts with him in the middle of the attack, has denied advance knowledge of his plan.
Her attorney could not be reached for comment on Monday but a relative said the family is "shocked" by the charges and maintains that Salman is a very simple person who was not involved and cooperated with investigators.
Salman, who was being held at the Santa Rita Jail, is due in federal court on Tuesday.
In an interview with the New York Times in November, Salman said that she met her husband, the son of immigrants from Afghanistan, on an Arab dating site and that six months into their marriage, he began beating her.
Although she was with him when he bought bullets at Walmart and scouted out the club in Orlando, she told the newspaper, "I was unaware of everything."
She claimed that she thought her husband was out with a friend the night of the mass murder until his mother called her at around 2 a.m. to ask about his whereabouts.
Salman said she did not know, and texted her husband: "Where are you?" a source close to the family told NBC News.
Mateen responded: "Do you see what's happening?"
Salman replied "No?" according to the source.
Mateen then responded "I love you, babe."
Last month, Salman applied to change the name of her 3-year-old son with Mateen.
Massacre survivor Demetrice Naulings, whose close friend was killed, was surprised to hear Salman was being charges so many months later.
"I'm just kind of shocked," Naulings said, adding that it was difficult to know how to feel since the feds had not outlined the allegations against Salman.
"I forgave her husband," Naulings said. "I pray for her and the kid."