The Richmond woman, identified as Bonnita McGuire Todd, died from gunshot wounds suffered inside her apartment in the 100 block of 20th Street around 11 p.m., according to police.
Todd's son, a 42-year-old man who works as a freelance auto mechanic, may have been the intended target of the shooting, Detective Nicole Abetkov said.
Investigators believe the shooter may have been an angry customer of the son, who has not been named, Abetkov said.
The man was grazed by bullets in the shooting and suffered minor injuries, according to police.
Police were searching the area in front of the home for evidence overnight, but no arrests have been made.
Anyone with information about the shooting is asked to call Richmond police Detective Danny Wellhausen at (510) 620-6860. Those who wish to remain anonymous may call (510) 232-8477.