The shooting occurred around 8 p.m. local time Sunday in Plano, about 20 miles northeast of Dallas.
When the officer entered the home, he saw several victims inside as well.
The suspect was killed at the location by an officer. Spokesperson for the Plano Police Department David Tilley said they are "trying to put all the puzzle pieces together". Details about what led the officer to shoot have not been released.
Two others at the home were hospitalized, and the police officer was not injured.
The gunman was among the eight who died at the scene.
The victims and suspect have not yet been identified. Sugg then heard a multitude of shots from what she said sounded like an automatic weapon. She opened her door and smelled gunpowder. The officer who shot the suspect was placed on administrative leave pending the investigation, which is protocol, he said.
The gunman was known by people in the house, Rushin said.
Once inside the home, police found nine gunshot victims.
The condition of the final victim in the hospital wasn't available during the press conference Monday.
Officials in the North Dallas suburb described the shooting as "unprecedented" and as something beyond anything they thought they ever would have to respond to. She says he showed up at her daughter's home and opened fire. CrimeOnline will provide updates when more information is available.
Sources say a Cowboys watch party may have been underway at the home when witnesses heard as many as 40 shots fired inside the home just after 8pm.