Mother was shot in a horrific murder-suicide while breastfeeding one of her twins

A Maryland mother of four was shot and killed while breastfeeding one of her twin babies. Police are calling it a murder-suicide related to domestic violence.

According to Prince, Taquia “Kiki” Nails, 32, was at her home on 62nd Avenue in Fairmount Heights, near the Maryland-Washington, D.C. border, when her estranged boyfriend, 26-year-old Quindell Mercer, attacked her around 11 p.m. on Tuesday shot George's County police.

Mercer, the twins' father, later turned the gun on himself.

Nails' mother, Lillie Nails, told FOX 5 News that the shooting stemmed from an argument between the couple.

“They went along with it and he asked them to say one more word,” said the grieving mother. “She said 'one more word' and he shot her twice in the head. When I got there the baby was covered in blood.”

Nails' 16-year-old niece, who was in the house at the time of the shooting, described what she saw.

“She told him several times to leave her house. He came out of the bathroom and shot her three times while she was holding the baby,” the niece said. “I tried to pepper spray him, but he pointed a gun at me. It got stuck and I left the house. When I closed the door, he ran out and started shooting at me.”

The family revealed to FOX 5 that the couple had a history of domestic violence. They said Nails wanted Mercer to be involved in the twins' lives, but she didn't want to remain in a romantic relationship with him – which upset him, they said.

“He was upset because she said she didn’t want to be in a relationship. And I'm going to make sure people know that because she deserves people to know the truth,” said Qiana Barnes, Taquia's best friend.

Last spring, Nails filed for a protective order against Mercer after he allegedly choked her, ABC7 reported. However, she chose not to go to court and the order lapsed.

“There’s a history to this,” said Kim Jackson, Taquia’s aunt.

“She had a restraining order. She did everything she was supposed to do in this situation. I would like to see stricter legislation to monitor these people and ensure they receive rehabilitation assistance.”

Nails' family is now mourning the loss and says she was a loving and devoted mother to her four young children. They told FOX 5: “We are falling apart. Everyone can't believe it. It’s Kiki.”

A fundraiser was set up to pay for Nails' funeral and support her four children.

Her sister London Nails said she never thought something like this would happen.

“She gave me all the advice. She’s the reason I wanted to be a mother,” London said. “Who will tell me anything? She’s not even here to tell me now… It’s like someone telling me how to be a mother?”