The widow of Pulse nightclub gunman Omar Mateen knew about the attack ahead of time, prosecutors said Tuesday during her appearance before a federal judge.

Noor Salman, 30, did not enter a plea on charges of aiding and abetting her husband in the months before the massacre that killed 49 people at the Orlando gay nightclub in June.

Salman was arrested Monday at her home near San Francisco. She and Mateen were living in Fort Pierce at the time of the attack. Her arrest — seven months after the massacre at Pulse nightclub — is the first in connection with the shooting.

"She knew he was going to conduct the attack," federal prosecutor Roger Handberg said. Handberg did not disclose any more details and would not comment after the 15-minute hearing, held in a courtroom packed with security officers.

Salman’s uncle said she is innocent.

“I want to tell her that, we’re here. We believe in her,” Al Salman told CNN.

But closer to home, there was a very different reaction to news of her arrest.

“I’m very pleased that someone will be held accountable for this,” Orlando Police Chief John Mina said.

"The reaction was really just a sigh of relief," said State Rep. Carlos Guillermo Smith, D-Orlando. "Justice, that’s all we want. That’s all that all of us are hoping for is justice.”

Smith said the June shooting at Pulse propelled him into action: The Florida lawmaker recently filed legislation for tougher gun laws. In tandem, Smith’s working to expand distribution for the victims’ compensation fund, and combat LGBTQ discrimination in the workforce and housing.

But, memories of that night are still fresh.

“It changed me in so many ways, ways I’m still trying to understand,” he said. “Some of my closest friends who survived, and I see what their experience is every single day. I see how they’re dealing with PTSD.”

A grand jury indictment unsealed Monday accuse Salman of helping her husband before the attack and accuse Salman of misleading investigators after the shooting. If convicted, Salman faces a maximum penalty of life in prison.

According to CNN, Salman told investigators that in the weeks leading up to the attack, her husband bought guns used in the June 12 attack.

Salman has denied prior knowledge of the attack, claiming she was abused by Mateen.

"Noor has told her story of abuse at his hands. We believe it is misguided and wrong to prosecute her and that it dishonors the memories of the victims to punish an innocent person," Salman’s attorney, Linda Moreno, said in a statement.

One of Salman’s former Port St. Lucie neighbors said he thinks she knows more than what she initially led on.

Robert Shepard lives across the street from the Woodland condominiums, where Salman and Mateen lived.

Shepard said he and neighbors have been talking about how an indictment could induce Salman to reveal more information.

“What she actually knows, were there other people involved, was it a larger party? How long was it in the works for? Do you think it will end with her?

"I don’t think it will," Shepard said.

In a statement, Pulse nightclub owner said she hopes this is another step in the healing process.

“We are grateful to know that the investigation into the Pulse tragedy continues and with positive results. What is most important is justice for the families, victims and all others affected. My hope is that this helps in the journey of healing,” Barbara Poma's statement said.

Mina said he knew within days of the attack that she would be locked up eventually.

"There is no doubt in my mind based on the information that I knew and that I received from the FBI over the past seven months that she knew, that she aided and that she could have prevented this tragedy," Mina told CNN.

At the memorial at Pulse on Monday, Alicia Villarama, who is visiting from southern California, said she hopes Salman will be truthful to authorities.

“I hope the wife, for the love of humanity... I’m expecting she will be honest to the FBI and the government, whether she was a part of it or not,” Villarama said.

Information from the Associated Press was used in this report.