FBI scrutinizing killer’s wife

ORLANDO, Fla. - The 30-year-old wife of the gunman who opened fire inside an Orlando nightclub is facing intense scrutiny as the FBI tries to determine whether she had advance knowledge of the massacre, federal authorities said.

In interviews with Noor Salman, the FBI has learned she accompanied her husband, Omar Mateen, on at least one trip to the club before the attack to do what a law enforcement official described as 'reconnaissance.”

The FBI has not arrested Salman as agents gather as much evidence as possible to determine whether she provided her husband with any assistance as he prepared for the assault at the club or had any inkling of his plan.

Reuters, citing an unnamed source, reported that a federal grand jury has been convened and could charge her as soon as Wednesday.

'It appears she had some knowledge of what was going on,” said U.S. Sen. Angus King, a Maine independent who a member of the Senate Intelligence Committee.

Iowa Sen. Chuck Grassley, chairman of the Senate Judiciary Committee, issued a letter demanding information about Mateen and his family members - including his wife - from the Department of Homeland Security and the Secretary of State.

Grassley asked for law enforcement records related to Mateen, as well as answers to whether his family members have refugee status or what types of visas they sought.

Although the Obama administration and congressional Democrats have called for stronger gun laws, the GOP senator told reporters he saw no need for them - and instead criticized the FBI.

Mateen, 29, a Florida security officer, who come under federal scrutiny twice before.

'If the FBI had been on top of things, he could have been arrested based upon the suspicions that they had beforehand,” Grassley said, according to Iowa Public Radio.

Investigators continue to seek a concrete motive in the attack that left 49 people dead Sunday in the worst mass shooting in U.S. history.

Mateen said he carried out the attack because he wanted 'Americans to stop bombing his country,” according to Patience Carter, 20, a witness who survived the rampage and heard the shooter make a 911 call.

But he also referenced the Boston Marathon bombers and pledged allegiance to the Islamic State.

Mateen made at least one other phone call during the standoff to an acquaintance in Florida, according to two law enforcement officials. It's unknown what he said.

The FBI has said it was also exploring whether anti-gay bigotry prompted the attack on Pulse, a popular gay nightclub. Adding another dimension to the probe, at least two witnesses at Pulse said Mateen had previously visited the club. They also said they had seen him on a dating app for gay men.

The bureau was facing questions - and Grassley's criticism over whether it missed warning signs during a 10-month probe of Mateen that ended two years ago.

During that investigation, the Mateen was placed on a terrorism watch list. His wife had apparently never come to the FBI's attention.

The FBI investigated Mateen beginning in 2013, putting him under surveillance, recording his calls and using informants to gauge whether he had been radicalized after he talked at work about his connections with al-Qaida and dying as a martyr.

It was during this probe, which ended in 2014, that Mateen was placed on a terrorism watch list.

After the FBI closed its preliminary investigation in 2014, his name emerged months later in a separate probe, this one looking into a Florida man who became the first American suicide bomber in Syria. Investigators said they did not find significant ties between them.

Reuters and Ed Tibbetts of the Quad City Times contributed to this report.