Omar Mateen

Charges against Noor Salman include "Aiding and Abetting by providing material support to a terrorist," Orlando's police chief said. The attack was the worst mass shooting in modern U.S. history.

In addition to surveillance video, police say an "examination of [Joseph Michael Schreiber's] social media account also shows multiple anti-Islamic posts and comments."

Early Monday morning, a fire broke out at the Florida mosque where Omar Mateen worshipped. Police say the fire was "set intentionally," and they say surveillance footage shows someone at the site.

Seddique Mateen, the father of Pulse nightclub shooter Omar Mateen, was seated behind Hillary Clinton at her Kissimmee, Fla., rally.

According to newly released documents, Omar Mateen told investigators he had boasted about ties to mass killers and terrorist groups because co-workers had verbally abused him for being Muslim.

A grand jury is considering possible criminal charges for Noor Salman, Omar Mateen's wife. Mateen's attack at a gay club killed 49; officials are looking at what Salman might have known beforehand.