Authorities reported to a home at 11 a.m. and found Martha Socorro Marin with a small puncture wound in the upper chest, KTLA-TV, Los Angeles, reported.
Marin was unconscious and authorities transferred her to UCI Medical Center, where she later died.
KTLA-TV said a 34-year-old man at the home told officers he accidentally shot Marin.
Astronomers offer more expansive view of universe
Beautician charged with giving client fatal silicone butt injection