Detectives are investigating a homicide as a case of self-defense, after a man was shot and killed inside a home near 117th Avenue and Cactus Road Sunday night, according to Sgt. Robert Peoples with the El Mirage Police Department.

Police say a woman called to report shots fired inside the home. When police arrived, they say they learned the woman shot the man after some type of domestic violence situation.

The woman was questioned and released.

"It's just sad just for somebody to lose their life. I would think, if it's going bad, just leave," said Ray Watkins, a neighbor.

Neighbors say it was obvious the couple was having trouble.

"The mother and the boyfriend used to argue a lot," Watkins said.

According to police, there was a history of domestic violence at the home--something neighbors say they were aware of in the woman's previous relationship.

"Yes, there was. Cops were called several times," said Katrina Martinez, a neighbor.

Its violence children should not have to witness, but police say the woman's adult daughter saw what happened and was able to back her mom's story.

Her two other young kids were also in the home and weren't hurt.

"She's a very sweet lady as far as I know--and her kids," Martinez said.

She added her granddaughter is friends with the woman's kids.

"She (her granddaughter) was there yesterday playing with the smallest girl," Martinez said.

Police aren't saying exactly why the woman fired in self-defense, but they say the man had some sort of weapon.

"I'm just stunned. I'm like--wow," Watkins said.

Police say the woman's two young kids are in the care of another family member and will likely be returned to their mother.