Officers responded to a report of gunfire at 715 S. Merrill Street in Corona at about 12:26 p.m.
Responding officers found Katherine Aguirre, 55, suffering from multiple gunshot wounds. She was hospitalized at Corona Regional Medical Center, where she was pronounced dead.
Corona resident Carlos Martin Quezada, 28, was named a murder suspect by police. He is the boyfriend of Aguirre's 28-year-old daughter, Crystal Lopez.
Police were also searching for Lopez, who's believed to be in danger. She was last seen Wednesday morning and had not responded to multiple calls to her cellphone. She was not believed to be involved in the murder of her mother.
According to Kimberly Perez, a long-time family friend, Quezada beat up Lopez during an argument Wednesday morning, so Aguirre called police. Lopez lived with Aguirre.
"I was there with her when she was talking to those cops, and then she came back to my house and she was scared. She said that she got a text message from his sister saying, 'Tell Crystal go run and hide because he's got a gun,'" said Perez.
Quezada later returned to the home looking for Lopez, but allegedly ended up shooting Aguirre. Friends say Lopez was taking her four sons to school at the time and hasn't talked to authorities since.
"Detectives do believe she is in danger at this time and investigators are trying to find her whereabouts," said Officer Jesse Cervantes with the Corona Police Department.
One of Lopez's friends, who didn't want to go on camera, told Eyewitness News exclusively that he talked to Lopez about two hours after the shooting. He said she was hysterical about losing her mother and wouldn't say where she was. She said she was scared to go home and scared that Quezada was after her.
Lopez's friends showed us postings on her Facebook page, including one that said, "Thanks everyone just trying to stay away from [expletive] physco (sic) thats after me...I'm just running."
Police told Eyewitness News they cannot confirm the Facebook postings and that they are following up on all leads.
Friends said Aguirre basically took care of everyone else who lived with her, including her father, her daughter and four grandsons.
"She always wanted to feed you and she always wanted to make sure you're OK. That's what Kathy was," said Perez.
Quezada is believed to be driving a blue/gray 1982 Chevrolet pickup truck with California license plate number 2B29305.
If you see Quezada please call 911 and do not attempt to approach or contact him. He is considered armed and dangerous. If you see or know the whereabouts of Lopez or how to contact her, please contact the Corona Police Department at (951) 736-2330, option 3.