ORLANDO (Web Desk) – The wife of the gunman who killed 49 people at an Orlando gay nightclub most likely knew of his plans and could soon be charged in connection with the deadliest mass shooting in America since 9/11.

A federal grand jury has been convened and could charge Omar Mateen’s wife, Noor Salman, as early as Wednesday, according to media reports.

“It appears she had some knowledge of what was going on,” said US Senator Angus King, a member of the Senate Intelligence Committee, which was briefed about the attack on Tuesday.

Read More: 50 dead, 53 injured in US gay nightclub mass shooting

“She definitely is, I guess you would say, a person of interest right now and appears to be cooperating and can provide us with some important information,” Mr. King told CNN.

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Mateen, who was shot dead by police after a three-hour standoff at the Pulse club early on Sunday, called 911 during his shooting spree to profess allegiance to various militant Islamist groups, including ISIS. In a video message, the terror group also claimed responsibility for the attack.

However, earlier this week FBI officials said that the Orlando gunman was most likely a “lone wolf”, acting without the support of any global terror network.