The incident happened around 9 p.m. Monday on Cerritos Avenue near Magnolia Avenue, according to the Orange County Sheriff's Department.
OCSD later identified the women as a mother and her daughter: Amadilia Noemy, 61, and Gabriela Amadilia Cruz, 34.
Screeching tires and a car horn could be heard on surveillance video from a nearby home.
Deputies who responded found two injured pedestrians at the scene. The women were struck by a white BMW while crossing the street on Magnolia Avenue.
They were both taken to the hospital, where they succumbed to their injuries.
Several of Cruz's longtime friends and co-workers came to the scene to create a makeshift vigil of flowers.
"She was a kind person. Good soul. Just recently got married. Just a sad, sad situation. We're all going to miss her dearly, and I'm sure her family is grieving over this as well, more than us," said friend and co-worker Phillip Sanchez.
Cruz's friends say she worked in Fullerton and got married just a few months ago in February. She and her wife have a young son, between 5 and 7 years old. They said Cruz was also a veteran, having served in the Army.
They said Cruz's mother was visiting her from Guatemala at the time of the tragic crash.
OCSD investigators said the two women were not using a crosswalk at the time of the incident. Neighbors say that's common because there's not one close by.
"I think it's a risk that almost everybody in this neighborhood has taken for a very long time, and we get accidents about every eight months," said area resident Preston, who witnessed the aftermath of the fatal crash.
The driver involved in the deadly crash stayed at the scene and was said to be cooperating with authorities. Authorities said DUI is not suspected in this case, and no one was arrested.
The crash remains under investigation.