The Fort Worth Police Officer shown in body-cam footage shooting and killing 28-year-old Atatiana K. Jefferson has resigned from the Police Department, before he could be fired. Fort Worth Police Chief Edwin Kraus said in a press conference Monday that Officer Aaron Dean was going to be fired, but resigned before he was terminated.

Chief Kraus added that Dean broke protocols in regards to use of force and de-escalation. Kraus added that Dean has not been cooperative in the investigation.

The Fort Worth Police have been in contact with the Texas Ranges about taking over the investigation, and have also been in contact with the FBI over a possible Civil Rights case.

Body-cam footage shows Dean, responding to a non-emergency wellness check call, searching around Jefferson's home, entering the backyard and approaching windows without identifying himself. Dean came to a window, screamed for Jefferson to put her hands up, again without identifying himself as a police officer, and shot Jefferson in less than 4 seconds.

Here's more from today's press conference.