The family of a 15-year-old girl was allegedly slain by her 20-year-old ex-boyfriend in a wealthy Los Angeles suburb spoke out a day after her death — revealing that she had recently broken up with her older beau.

Mina Kurdian was showering at her Arcadia home when Paul Anthony Cruz Jr. allegedly broke in and shot her in the head, according to police and her grieving family.

The teen’s grandfather, Nick Eftekhari, told the California Post that Mina broke up with Cruz several weeks before the alleged murder. Cruz wanted to make up with her, but became upset when they couldn’t reconcile, Eftekhari said.

Cruz then broke into Mina’s home, went into the bathroom and shot her, the grandfather said. Officials pronounced Mina dead at the scene.

Authorities said Cruz fled the scene and he was later found in a Petco parking lot in Pasadena with a self-inflicted gunshot wound. As of Friday morning, Cruz was in the hospital in critical condition.

Eftekhari suggested he did not approve of the relationship and the five-year age gap between the adult and juvenile, but he was unaware of it until recently. He estimated that the pair had been dating for a few months at the time of the alleged murder.

“I would’ve stopped it earlier,” he said.

Mina’s grandfather described her as a “beautiful girl inside and outside.”

Neighbors told ABC 7 that Mina had a younger sister and that her relationship with her boyfriend appeared fine.

“Her mother is a wonderful lady, you know, she works hard for her two kids and she has a younger sister,” one neighbor said. “They seemed to get along well with her boyfriend, you know, they got along so well and we saw them all the time… he was very polite. You never know. You never know who you’re with.”

The investigation into Kurdian’s death remains ongoing.