DALLAS (CBSDFW.COM) – What began as a shots fired investigation lead to a SWAT situation in a Dallas residential area.

Police say officers were called to a home in the 500 block of Highcrest Drive, in the South Oak Cliff area of Dallas, around 12:30 a.m.

When officers arrived they found an adult male who said he and his wife had had an argument and that the woman had grabbed a gun, fired several shots and barricaded herself inside the house with two of her children — a 12-year-old boy and 8-year-old girl.

At a morning press conference Dallas Police Chief U. Renee Hall said, “No matter how much violence we respond to in a city, and throughout my almost 22 years in law enforcement, these kinds of scenarios are the absolute worst.”

(credit: CBSDFW.COM)

A SWAT team was called to the scene and after several hours of negotiations one of the children — the 12-year-old — was able to escape the house.

After more negotiations SWAT tried to make entry inside the house and the the 35-year-old woman opened fire. A Dallas police officer was grazed by one of the bullets, but is said to have no injuries.

At the scene, CBS 11 News photographer Tim Lavow heard the sound of shots being fired.

Chief Hall said the SWAT team retreated from the house, but a short time later heard 2 additional shots. “They attempted to make a second entry into the location. When they got inside they found the 8-year-old and the black female suspect. She’d shot herself and her 8-year-old daughter.”

Both the woman and child were pronounced dead at the scene. “So again, a tragic situation of violence… family violence that is really overtaking our community,” Chief Hall said.

After the press conference about the standoff the Chief went on to say that in the last 48 hours a number of Dallas police officers had been fired on several times and asked where there was no community outrage about it. “We sign up to take care of our community. We sign up to protect and serve. And what happens when the community that we swear to protect and serve turns around and turns on us,” she said. “We want to keep this City of Dallas safe, but we can’t do that if we are now being preyed upon.”