The FBI on Monday arrested the wife of the lone gunman who last year killed 49 people and injured dozens when he opened fire in Orlando's Pulse nightclub.

According to The New York Times, FBI agents arrested Noor Salman at her home near San Francisco and have charged her with obstruction.

Omar Mateen, 29, died in a gunfight with police. In a 911 call Mateen made from inside the gay nightclub, he claimed allegiance to ISIS.

According to various reports, Salman told federal investigators that she was with her husband when he purchased ammunition but that she was “unaware” of his plans.

The Orlando shooting is considered the deadliest in modern U.S. history.

Salman is expected to appear in a federal court on Tuesday, the Times reported.