The government accuses Salman of providing terroristic information to Mateen.
Prosecutors claim that Salman scouted locations with Mateen, and deflected police attention away from the mass murderer. She could spend the rest of her life in prison.
Jurors will see some of the evidence inside Pulse Nightclub to prove that Omar Mateen was the shooter.
It's been nearly two years since the Pulse nightclub shooting in Orlando. Salman has pleaded not guilty to both charges.
"If some of those great people that were in the club that night had guns strapped to their waist or strapped to their ankle, and if the bullets were going in the other direction, aimed at this guy who was just open target practice, you would've had a situation folks, which would have been always disgusting, but nothing like the carnage that we all as a people suffered this weekend".
The 31-year-old grew up in Rodeo, California after her parents emigrated from the West Bank in 1985, according to The New York Times.
She was Mateen's second wife.
Prosecutors also say that Salman texted Mateen "If ur mom calls say nimo invited you out and noor wants to stay home", as an alleged cover for the night of the attack. "We believe it is misguided and wrong to prosecute her and that it dishonors the memories of the victims to punish an innocent person". Authorities said Salman had given them conflicting accounts.
Salman has denied any involvement or prior knowledge in her late husband's premeditated plans, but later confessed to scouting out the club with him prior to the attack and accompanying him when buying ammo.
Her attorneys have said she could not predict what Mateen meant to do and tried to convince a judge that the statements she made to investigators immediately after the shooting were obtained unlawfully.