Police declined to say what was taken.
The gunman, described as a black or Latino man wearing white gloves, got over 6-foot-tall gate and walked through a unlocked back door. Once inside, the robber bound the man and woman with packing tape, then took jewelry and cash before fleeing.
No getaway car was seen. The gun may have been a pellet gun.
The suspect was dressed in all black and had some acne scars, it was reported.
Anyone with more information was asked to call police at (310) 444-0701.