John Bacon, and Kevin Johnson

USA TODAY

The wife of Omar Mateen, the man who killed 49 people in a shooting rampage at an Orlando nightclub last June, was arrested Monday on charges of obstruction of justice and aiding and abetting by providing material support to a terrorist organization.

Noor Salman was taken into custody by the FBI at her Northern California home.

Salman will make an initial appearance on Tuesday morning at the federal courthouse in Oakland, Calif., the U.S. Attorney's Office for the Middle District of Florida said via Twitter.

The charges could indicate that authorities believe she knew more about the assault — the most deadly mass shooting in U.S. history — than she has previously admitted.

Orlando Police Chief John Mina said he welcomed the arrest.

"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 in a statement. "But today, there is some relief in knowing that someone will be held accountable for that horrific crime."

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Orlando Mayor Buddy Dyer echoed those thoughts, issuing a statement thanking law enforcement agencies for "bringing some justice to this terrible tragedy."

"Our community continues to heal and we remain focused on taking care of the needs of their victims and their families," Dyer said.

Salman, in interviews with federal investigators after the shooting, allegedly acknowledged driving Mateen to the Pulse nightclub at least once before her husband launched the assault. But she told The New York Times in November she was unaware of his intentions until he sent her a 4 a.m. text message the night of the shooting, asking whether she had seen what happened on the news.

The last message from her husband was a text saying, “I love you babe.”

Scores of people were wounded in Mateen's assault. During the siege, Mateen called a local TV station and 911 to "pledge allegiance" to the Islamic State and its leader, Abu Bakr al-Baghdadi. After hours of negotiations failed, authorities became concerned that Mateen would blow up the club. Officers finally smashed through a wall and engaged in another firefight with Mateen, who died at the scene.

Salman, who has Palestinian roots, grew up in the small suburb of Rodeo, Calif., about 25 miles northeast of San Francisco.

Salman met Mateen online and they married in 2011. Last month, Salman petitioned a California court to change the name of the couple's 4-year-old son, who is partly named for his father. A hearing was set for next month.