Did the Orlando shooter’s wife know of his plans? Grand jury investigates.

A federal grand jury may bring charges against Noor Salman, the wife of Florida attacker Omar Mateen, according to law enforcement officials.

First Look

The wife of Omar Mateen, who killed 49 people at an Orlando nightclub in what many are calling the worst mass shooting in American history, could face criminal charges in connection with her husband's crimes.

Investigators say Mr. Mateen's wife, Noor Salman, had prior knowledge of his plan, according to Sen. Angus King (I) of Maine, who sits on the Senate Intelligence Committee. Senator King said Ms. Salman appeared to be cooperating with investigators, after earlier reports indicated that she had initially shown reluctance. 

The new details highlight the legal – and perhaps ethical – obligation to inform authorities when a loved one is preparing to commit violent crimes. Salman told law enforcement agents that she knew of her husband's plan to carry out an attack, but tried to talk him out of it, according to ABC News. 

Prosecutors have assembled a federal grand jury to decide whether to bring criminal charges against her. They could charge her as an accessory to some 49 counts of murder and 53 counts of attempted murder, a federal law enforcement source told Fox News.

Sources with knowledge of the investigation told the network that she had accompanied her husband when he bought ammunition and a holster. She may have gone along with him when he cased out Pulse nightclub and other locations – including Disney World resort and a shopping complex called Disney Springs – as potential targets, reported CNN. Mateen reportedly made a final trip by himself to Disney Springs just hours before beginning the attack on Pulse.

Mateen is said to have called 911 during the carnage. He also placed another phone call. That person, according to Fox, might have been Salman. 

The shooter’s father, Seddique Mateen, told ABC that he had no idea if his son's wife had known about the attack before it happened. Seddique Mateen, though not the focus of investigations, has himself come under public scrutiny after posting a Facebook video on Monday that apologized for his son’s actions while saying, "God himself will punish those involved in homosexuality." 

Even as LGBT people enjoy greater acceptance among Americans and gain important legislative victories – such as last year's Supreme Court decision legalizing gay marriage – violence against LGBT people has remained steady, as The Christian Science Monitor reported earlier this week.

Lorrie Jean, who runs a Los Angeles advocacy center and spoke at a pride march on Sunday in that city, told the Monitor, "We cannot allow this kind of violence to silence us."

"Today's march was about pride, but it was also an act of protest against fear, bigotry, and violence, so that's how the whole community is responding."

This report contains material from the Associated Press and Reuters.