The shooting happened shortly after 8 a.m. in an alley on the 800 block of South Townsend Street.
Santa Ana police say two officers in separate squad cars confronted a woman in the alley armed with what looked like a real gun. As officers approached, an officer-involved shooting ensued.
The woman was transported to UCI Medical Center where she later died.
Family members confirm the woman was 35-year-old Jessica Gonzalez. Authorities had been looking for her for three days.
Orange police suspected Gonzalez of gunning down her long-time partner, 44-year-old Jennifer Solorio.
Residents on the 2000 block of East Palmyra Avenue in the city of Orange heard the gunfire Thursday afternoon. Solorio was found on the sidewalk suffering from gunshot wounds. She was transported to a hospital but later died.
A relative of Gonzalez says family members are grieving the deaths of both women, because Solorio was like part of their family.
Solorio's daughter told Eyewitness News that her mother and Gonzalez had been involved in a romantic relationship for 13 years.
Details about the circumstances leading up to the officer-involved shooting have not been made available but neighbors say they heard at least four gun shots.
Police said they recovered a replica hand gun from the crime scene.
"There is a weapon in the alley way that does not belong to the officers," said Santa Ana police Cpl. Anthony Bertagna. "At this point, that's all the facts that we know."
No officers were injured during the incident.
Dozens of evidence markers were seen in the alley. The shooting will be investigated by the Orange County District Attorney's Office which is routine protocal following officer-involved shootings.