"Every time I saw her, I would beg her. Don't talk to him. Leave him and it seemed like the more I did that, the more she would see him."
From that exclusive interview, Eyewitness News is learning more about the victim and the man now being held for her murder in San Carlos.
This family wants the public to know Karina Castro, to understand what she went through, and to help bring her children home. They were taken by social workers after the attack.
Castro's grandmother, Danielle Gannon, met with KGO-TV at her home in Vallejo on Friday.
She invited the team inside to meet her son, Marty Castro - the father of the victim in Thursday's beheading.
Castro: "She was an amazing girl."
Gannon: "She was an amazing woman, very stubborn, determined to raise her daughters on her own."
Karina Castro was 27 years old, got her GED, and worked as a Door Dash driver. She left behind 7-year-old and 1-year-old girls.
She had the youngest with the man now held for her murder, 33-year-old Jose Raphael Solano Landaeta.
The family says he goes by the name Rafa Solano, and that he didn't work. KGO-TV found some rap songs he posted on YouTube.
Gannon: "He is a diagnosed schizophrenic on meds. And he would use that as an excuse for his behavior. He drank excessively and you're not supposed to do that on those kind of medications."
The family confirms what the investigative team learned from law enforcement sources Thursday, that Solano had been violent with Castro and she got a restraining order against him in April, but continued to interact with him.
Castro: "If there's somebody out there abusing your daughter, don't take off. Don't let it go. Don't take no for an answer. You feel responsible, no matter what anyone says."
Gannon: "I do too, baby."
In the day before the murder, Snapchat messages between the couple got very contentious. The I-Team obtained more than a dozen, most with language too explicit to show.
She threatens to tell the world about Solano's criminal record that includes a rape conviction involving a minor. He calls her "snitch lip" and warns her "F*** around and find out."
Castro fires back, "U wanna put a target on my back, ur homies gunna kno the real u" and threatens to expose his sexual relationship with another man.
She adds, "Dude, go head try and take my a** out."
Just hours later, they had a confrontation in the street outside her apartment -- her daughters safely inside.
Marty Castro: "He got really mad, went to the trunk of his car, pulled out whatever it was and killed her right there behind her car."
Stunned neighbors saw it play out. Chapel Thorborne saw the gruesome aftermath.
Thorborne said, "The head was underneath the car and she was laying in back of the car, just severed, and then they covered her up."
Castro's family said they learned about the killing Thursday evening through media reports. Her father rushed to the scene and saw the fire department spraying down the blood on the street.
Castro: "When the deputy walked up, he would not confirm who it was. But I said that she owned that black Volkswagen. He said yeah, that's required. That's my daughter."
Social workers had already taken the girls. Gannon and Marty Castro want them as soon as possible, but CPS said they'd have to go through the application process.
Gannon says, "I want those girls. That's what I want first, then I want Rafa to fry in jail. I don't care what happens to him."
As KGO-TV left, Marty Castro was in tears, calling the coroner to get his daughter's effects, calling CPS to get his grandchildren back, and calling animal control so he can pick up her dog and two cats.
The arraignment for Solano was scheduled for Friday afternoon, but it has been pushed to Monday.
The city of San Carlos and the Community Foundation are accepting donations to help Castro's children. You can make a donation here.
Love shouldn't hurt, but domestic violence can happen in any relationship - regardless of age, race, sexual orientation, religion or gender. These local resources can help.