After a white police officer responding to a report of a house door standing open killed a black woman inside her own home on Saturday, an attorney for the woman’s family said the officer had not had time to perceive a threat before shooting.

“You didn’t hear the officer shout, ‘Gun, gun, gun,’” attorney Lee Merritt said after viewing video taken from a Fort Worth officer’s bodycam during the shooting death of Atatiana Jefferson, 28.

“He didn’t have time to perceive a threat. That’s murder.”

We have communicated with the family and shared our serious and heartfelt concern for this unspeakable loss Lt Brandon O'Neil

Jefferson’s family told KXAS TV she was watching her eight-year-old nephew when she was killed. A neighbor had called a non-emergency line to report that the front door to the house was open.

In a brief statement to media on Sunday, Lt Brandon O’Neil of Fort Worth police said the officer would be interviewed on Monday by the department’s major case unit.

“The officer observed a person through a rear window in the residence and fired a shot at that person,” O’Neil said. “The officer did not announce that he was a police officer prior to shooting. What the officer observed and why he did not announce ‘police’ will be addressed as the investigation continues.

“We have communicated with the family and shared our serious and heartfelt concern for this unspeakable loss.”

In an earlier statement, police said officers responding to the call about the open door saw someone near a window inside the home. One drew his weapon and fired after “perceiving a threat”.

The officer, who has been on the force since April 2018, was placed on administrative leave pending an investigation. His name was not released.

Merritt said Jefferson’s family expects “a thorough and expedient investigation”.

The video released by police shows two officers searching the home from the outside with flashlights. One shouts: “Put your hands up, show me your hands.”

One shot is then fired through a window. The officer does not identify himself as an officer in the video.

It’s another situation where the people that are supposed to protect us are actually not here to protect us Amber Carr

“It’s another one of those situations where the people that are supposed to protect us are actually not here to protect us,” said Jefferson’s sister, Amber Carr. “You know, you want to see justice, but justice don’t bring my sister back.”

An aunt, Venitta Body, said the family does not understand why Jefferson was killed.

“It’s like from the moment we got the call, it’s been more and more inconceivable and more confusing,” Body said. “And there has nothing been done in order to take away that confusion.”

Neighbor James Smith, who called police about the open door, told reporters he was just trying to be a good neighbor.

“I’m shaken,” he said. “I’m mad. I’m upset. And I feel it’s partly my fault. If I had never dialed the police department, she’d still be alive.”

Smith said Jefferson and her nephew typically lived with an older woman, who has been in hospital.

“It makes you not want to call the police department,” he said.

Fort Worth police said they released bodycam footage to provide transparency, but any “camera footage inside the residence” could not be distributed due to state law.

The bodycam video released to media did include blurred still frames showing a gun inside a bedroom at the home. It was unclear if the firearm was found near Jefferson.

The shooting comes less than two weeks after a white former Dallas police officer was sentenced to 10 years in prison after being convicted of murder in the shooting of her black neighbor inside his own apartment.

Amber Guyger, 31, said she mistook Botham Jean’s apartment for her own, which was one floor below. Merritt also represents Jean’s family.