The now-former Fort Worth police officer who shot and killed Atatiana "Tay" Jefferson in her own home has been officially arrested on murder charges.

Atatiana Jefferson was shot and killed by Aaron Dean over the weekend while Dean was patrolling Jefferson's house during a wellness call. Just after 2 a.m. on Saturday morning, a neighbor of Jefferson's called the Fort Worth non-emergency number to report Jefferson's front door was open and lights were on the house. While looking around the outside of the house, Dean reported that he saw someone in the window, perceived a threat, and opened fire. In the released body-cam footage, it took Dean less than 4 seconds to pull his firearm, call for Jefferson to show her hands, and fire the fatal shot. At no point did Dean identify himself as a police officer and officials confirmed that neither Dean nor the other officer on the scene tried the front door before looking around.

In a press conference Monday, Fort Worth Police Chief Ed Kraus said,

I certainly have not been able to make sense of why she had to lose her life. On behalf of the men and women of the Fort Worth Police Department, I'm so sorry for what occurred.

Kraus confirmed that he was scheduled to meet with Dean on Monday to discuss what happened, but Dean resigned just before the meeting and has not been cooperating with the investigation. Kraus said at the conference that it was his intention to terminate Dean at the meeting for unprofessional conduct and violating department policies on the use of force and de-escalation.

According to ABC News, Fort Worth Mayor Betsy Price called out the Fort Worth police department for releasing images of a firearm found in Jefferson's home, saying it was irrelevant. Others have accused the FWPD of trying to paint Jefferson in a bad light and give the public a perception that Dean was justified in his actions. Chief Kraus agreed with the mayor, saying it was a mistake for the department to release the photo,

I can't imagine most of us, if we thought we had somebody outside our house that shouldn't be there and we had access to a firearm, that we wouldn't act very similarly to how she acted.

According to Jefferson's family, she had a concealed carry license.