The suspect has been identified as 49-year-old Julio Garay. Investigators say Garay is the estranged husband of the victim.
Garay was arrested late Tuesday night in Marina, California, more than 120 miles west of Madera. He was booked on homicide charges.
The deadly shooting took place at about 3 pm near the Camarena Healthcare Clinic in Madera, where 32-year-old Calley Jean Garay of Chowchilla had gone for treatment.
She and her three children were entering her car when she was shot. The woman was taken to hospital, where she died.
According to Madera Police, the woman, Calley Jean Garay, who is from Chowchilla, was targeted. Julio followed her to the clinic where she was shot multiple times trying to protect her children.
Camarena medical staff helped Calley until she was taken to the hospital where she died from her injuries.
The scene was so heartbreaking that police chief Dino Lawson struggled to describe it.
"This is despicable," said Lawson. "I can't think of anything more horrific than to do something like this - a cold-blooded act in front of the mother's children. The mother, being a mother, sacrificed her own life, and laid across the bodies of her children to save them."
This was just the second homicide in the city of Madera in 2020.
"In my 34-year career and 34 years in law enforcement I can't recall any case similar to this one," said Lawson.
Julio has a long criminal history, including a domestic violence charge back in May. He was out on bail.
"Abuse is not okay and it is not justified," said Kendy Villa, crisis service manager at the Marjaree Mason Center.
Villa said they always work with victims in hopes of preventing these kinds of tragedies.
Since the pandemic started, the center has seen an increase in more violent cases.
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Villa said we need to do better as a community to help those in need.
"Support those that are going through intimate partner violence, encourage them to seek support," she said.
Camarena Health's CEO released a statement saying in part, "Camarena Health is deeply pained by this horrific event. There are no words to convey the depth of sadness that we feel and are heartbroken for this heroic mother whose life was tragically cut short."
All three children are below six years of age and mental health professionals are working with them.
If you are the victim of domestic abuse, or you know someone who is, there is help available 24/7. In Fresno County, call the Marjaree Mason Center at (559) 233-4357. In all other locations, call the National Domestic Violence Hotline at (800) 799-7233.