Family: Dad Shoots Twin Babies to Death in Their Mom's Arms Before Killing Her Father

(INSIDE EDITION) - A mother lies hospitalized in critical condition after the father of her twin baby girls shot them to death in her arms, and then killed the woman's dad, according to her family.

Ultimately, Gawain Rushane Wilson turned the weapon on himself and died at the scene, authorities said.

The carnage took place in the Jacksonville, Florida, home of Travis Hiatt, the twin's grandfather. His daughter, Megan, and her five-month-old girls Hayden and Kayden, had been living him, authorities said, according to local reports.

Wilson allegedly entered the home and forced his estranged girlfriend to pick up the babies.

"He wanted to destroy her world," the woman's mother, Melissa Bateh, told First Coast News about last week's devastation. "He wanted her to watch it be destroyed."

Bateh said her 22-year-old daughter told her, "Mama, he killed them. He killed them in my arms. He made me hold them when he killed them. He made me watch."

Jacksonville Sheriff's deputies declined comment when reached by INSIDE EDITION Thursday evening.

Bateh said her daughter had to crawl through her infants' blood to reach her father, who was dying on the floor. "He wanted her to tell her brother that he was the best son ever and he loved him."

The mother said she had misgivings about her daughter's relationship with Wilson, who she described as threatening and controlling.

He would limit Megan's contact with family and friends and take away her cell phone, Bateh said.

"As a parent, you know," she said. "I knew in my gut their relationship was not healthy."