Authorities said the incident started shortly after midnight in Glendale, where Davis allegedly confronted her husband, Nolan Davis, and a 36-year-old woman who was with him outside the bar.
The suspects were later found dead inside the vehicle from what police believe were self-inflicted gunshot wounds, only a few blocks away from the mosque.
The livestreamer has drawn attention online for inflammatory videos in which he confronts strangers while shouting racial slurs and making offensive remarks.
Footage showed dozens of Secret Service agents and National Guard members deployed, with sections of nearby sidewalks cordoned off by yellow police tape.
The shooting reportedly happened near the Seminole Hard Rock Hotel & Casino, a popular destination in Hollywood known for its nightlife and entertainment.