Investigators into the Pulse nightclub shooting continue to look at the gunman's wife, what she knew and when she knew it.

Authorities said they believe Noor Salman knew about her husband's plot ahead of time, said an official who was briefed on the progress of the case but insisted on anonymity to discuss a continuing investigation.

On Tuesday, media reported that Salman had gone with her husband to buy ammunition and had also driven him to the Pulse nightclub on a previous occasion because he had wanted to survey it.

Orange County State Attorney Jeff Ashton said indirect involvement in the shootings could lead to charges.

"Well having knowledge is not a crime in Florida," Ashton said. "But if you know a crime is going to be committed and you want it to happen and you do something to help it happen, you are responsible just as if you did it yourself. You're called a principle.

"So if there's evidence that somebody out there helped him get this done, knew it was going to happen, that person could be guilty of 49 counts of first degree murder."  

Investigators have spoken extensively with her and are working to establish whether she recently accompanied her husband to the nightclub, officials said.
Salman, a 30-year-old California native of Palestinian heritage, was escorted to and from the condo Monday night by authorities.

Salman made a brief visit to their first-floor apartment late Monday, escorted by police and her brother-in-law. Her father-in-law said she came to retrieve clothing. She did not speak with reporters.

Her current whereabouts are not publicly known.