According to police, a man, who was accompanied by another man and a woman, pointed a gun at someone near the 14500 block of Ventura Boulevard around 2 p.m. Friday.
The Ralphs was evacuated as authorities searched the premises.
When police got to the scene the suspects went into a parking structure of a business. The female suspect was detained shortly after 4 p.m.
SkyFOX on the scene shows multiple LAPD cars centered around the parking garage entrance on Hazeltine Avenue.
No injuries were reported.
Police have not yet released a detailed description of the two outstanding suspects.
Tune in to FOX 11 Los Angeles for the latest Southern California news.