A man is believed to have butchered his girlfriend and her 6-year-old daughter inside their Bronx apartment before killing himself on Sunday, March 6.

The bodies of Gabrielle Muniz, 26, and her child, Rozara Estevez, were found with stab wounds all over in a bedroom inside their Monticello Avenue home around 11:50 p.m. Saturday, March 5, police said.

Sources identified the suspect as Gabrielle’s boyfriend, Caleb Duberry, who was on parole for assault at the time.

Duberry, 35, then barricaded himself inside an apartment about a mile from his girlfriend’s and fatally stabbed himself with a knife as police closed in around 12:15 p.m. Sunday, March 6, sources said.

The dead woman’s sister, Gisselle Muniz, told The Post Sunday: “I’m disgusted at what happened because it not only took my sister but my niece.

She added: “I’m sure she watched her mommy die before she was taken.”

Gisselle, who lives in Florida, said her sister had been with Duberry for less than a year. Sources said Rozara was not his child.

“I’m really good with vibes and I honestly didn’t really like him,” Gisselle said. “I just knew she was happy.”

Gabrielle worked from home for a law firm and was in school studying pharmacy. She wanted to be a doctor someday, her sister said.

“She was doing so well. I never expected this to happen,” Gisselle said. “She did so much for her daughter. That was her main motivation.”

Duberry had numerous arrests for gun possession, robbery and assault, according to sources.

A motive in the killing was not immediately clear.