A white police officer who shot and killed a black woman Saturday through a back window of her home has been booked into jail on a murder charge, police in Texas said Monday. >> Read more trending news Fort Worth police Lt. Brandon O'Neil said the officer involved, identified as 34-year-old Aaron Dean, failed to announce himself as a police officer before he fired the single shot that struck and killed Atatiana Jefferson, 28. The shooting happened around 2:25 a.m. Saturday after a neighbor called a non-emergency line to report her home's front door had been left open. Update 2:45 p.m. EDT Oct. 15: Authorities confirmed in an arrest warrant affidavit released Tuesday that Atatiana Jefferson's 8-year-old nephew was in the room when a Fort Worth police officer shot and killed her inside her Tarrant County home on Saturday. Authorities said Jefferson cried out after an officer, identified as 34-year-old Aaron Dean, shot her through a window while responding to a call from her neighbor. Investigators said Jefferson's neighbor had noticed her front door was open in the pre-dawn hours Saturday and that he called a police non-emergency line to have them perform a welfare check. Jefferson's nephew told a forensic interviewer he was playing video games with his aunt when she heard noises from outside her home. He told authorities she took her handgun from her purse and pointed it toward the window before she was shot. Police Chief Ed Kraus said earlier Tuesday that a gun was found in the room after authorities entered the home, but he added that 'it makes sense that she would have a gun if she felt threatened or thought someone was in the backyard.' Police on Monday arrested Dean to face one count of murder. Jefferson's family has called for an independent investigation into the shooting. Police said Monday that they've presented the case to the Texas Rangers, who declined to take it, and to the FBI. Update 11:25 a.m. EDT Oct. 15: Police Chief Ed Kraus confirmed Tuesday that Fort Worth police arrested Aaron Dean on Monday night without incident. Kraus said Tuesday that Dean had yet to give a statement on the shooting to police. Dean joined the Forth Worth Police Department in August 2017 and resigned Monday amid an investigation into the shooting of Atatiana Jefferson, 28, Kraus said. 'There's absolutely no excuse for the incident and the person responsible will be held accountable,' Kraus said Tuesday during a brief and emotional news conference. 'I don't have any officers saying this action should not have been taken against this individual, this officer. I'm getting the opposite reaction. ... The officers are hurting.' He reiterated Forth Worth's city manager, who said Monday that authorities were considering bringing an independent, third party in to review the police department's procedures. Jefferson's family has called for an independent investigation of the shooting. 'We're looking at bringing an independent third party group to come in and evaluate our policies, our practices and our training to ensure that we are above best practice standards,' he said. Update 11 a.m. EDT Oct. 15: Police in Forth Worth are holding a news conference Tuesday morning to provide updates on Monday's arrest of Aaron Dean, the police officer who shot and killed Atatiana Jefferson in her home over the weekend. Update 9:55 a.m. EDT Oct. 15: Fort Worth police are expected to hold a news conference Tuesday morning, one day after police arrested Aaron Dean on suspicion of murder. Chief Ed Kraus said Monday that Dean resigned from his post with the Forth Worth Police Department before he could be questioned about the shooting. Kraus told reporters Dean would have been fired if he hadn't resigned. He had been with the Forth Worth Police Department since August 2017. Jail records show Dean was out of custody after posting bond Monday night, less than four hours after his arrest. He had been held on $200,000 bond Update 9:45 p.m. EDT Oct. 14: A $200,000 bond has been set for Aaron Dean in the fatal shooting of a black woman inside the woman's Fort Worth home. Jail records did not list an attorney for Dean. The attorney for the family of a black woman shot and killed in her Fort Worth home by a white police officer says they are 'relieved' that the now-former officer has been jailed on a murder charge. Update 8 p.m. EDT Oct. 14: Aaron Dean has been charged with murder and was booked into the Tarrant County jail in Fort Worth, Texas Monday afternoon, according to KDFW. Bond has not been set. Update 2:25 p.m. EDT Oct. 14: Police said an officer who shot and killed a Texas woman Saturday morning in her own home resigned Monday before he could be fired from the Fort Worth Police Department. Police Chief Ed Kraus said Officer Aaron Dean joined the department in August 2017 and was commissioned as a police officer in April 2018. Police placed him on detached duty after the shooting and stripped him of his badge and firearm. Kraus said Dean resigned before he could cooperate with investigators. '(Atatiana's) father called this shooting senseless and I've certainly not been able to make sense of why she had to lose her life,' Kraus said. The chief said the case is subject to an internal and a criminal investigation. He added that authorities have presented the case to the FBI because of possible civil rights violations. Officers also presented the case to Texas Rangers. Kraus and Fort Worth Mayor Betsy Price apologized to the community for the shooting. 'We are all heart-broken today,' Price said. 'Atatiana was a beautiful, smart, amazing young woman by all accounts who was unjustly taken from her family.' Update 12:10 p.m. EDT Oct. 14: The family of Atatiana Jefferson held a news conference Monday, days after the 28-year-old was shot and killed in her home by a Fort Worth police officer. Relatives said an agency other than the Fort Worth Police Department should investigate Jefferson's death. One of her sisters, Ashley Carr, described her as 'a smart, ambitious, kind person with a nurturing spirit.' Carr said her sister had a bachelor's degree in biology from Xavier University and that her coworkers saw her as a person of integrity. Original report: A Fort Worth police officer did not announce that he was an officer before firing a single shot striking Atatiana Jefferson, who was inside the room with the boy, Fort Worth police Lt. Brandon O’Neil said at a news conference Sunday. “What the officer observed and why he did not announce ‘police’ will be addressed as the investigation continues,” O’Neil said in a statement. “The members of the Fort Worth Police Department share your very real and valid concerns, as do the members of this city and people across the country. This tragic loss of life has major ramifications for all involved, especially the family of Ms. Atatiana Jefferson.” O’Neil declined to answer reporters’ questions and said Fort Worth police Chief Ed Kraus plans to conduct a more in-depth news conference Monday. The family also confirmed Jefferson was watching her nephew at the time. The two typically lived with an older woman who’s been in the hospital. Jefferson’s family is seeking answers. “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.” Lee Merritt, an attorney for the family, said the officer never had time to perceive a threat. “You didn’t hear the officer shout, ‘Gun, gun, gun,’” Merritt said. “He didn’t have time to perceive a threat. That’s murder.” Neighbor James Smith called a nonemergency line Saturday for a welfare check after noticing the lights were on and a door was open. Fort Worth police released bodycam footage soon after the incident Saturday. Video shows officers with flashlights and guns drawn scanning the perimeter of the home. The front door appears to be open although the screen door is closed. As officers continue to walk through the property, one of them sees a person standing at a dark window and yells: “Put your hands up. Show me your hands,” before firing a single shot. Police located a gun in a bedroom when they entered the house. Investigators did not indicate if Jefferson was holding the firearm. The officer, who has not been identified, has been placed on administrative leave. He has been with the department since April 2018. He is scheduled to be interviewed by investigators Monday. 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 fatal shooting of her black neighbor inside his own apartment. Amber Guyger, 31, said during her trial that mistook Botham Jean’s apartment for her own, which was one floor below Jean’s. Merritt also represents Jean’s family. The Associated Press contributed to this report.