The wife of Omar Mateen, the Islamic man who killed 49 people in Orlando, Florida, has been formally arrested for obstruction, a law enforcement official said Monday.

Noor Salman was taken into custody by F.B.I. agents at her home outside of San Francisco.

Noor knew about the planned attack on the Pulse nightclub and failed to report the information to authorities according to NBC News:

Noor told the FBI she was with him when he bought ammunition and a holster, several officials familiar with the case said. She told the FBI that she once drove him to the gay nightclub, Pulse, because he wanted to scope it out.

Prior to carrying out the ISIS-themed attack, Omar Mateen bought nearly $9,000 worth of jewelry at a nearby store in Orlando, according to ABC News.