what she says was a terrible mistake our gabe gutierrez was in the courtroom. reporter: on the witness stand, it didn t take long for 31-year-old amber guyger to break down she was asked about the moments leading up to the shooting death of botham jean last september. i was scared whoever it was inside my apartment was going to kill me, and i m sorry. i have to live with that every single day. reporter: the fired dallas officer thought jean was a burglar inside her apartment when in fact, she mistakingy walked into his unlocked apartment. she said jean began walking towards her. i pulled my gun out. i yelled at him, let me see your hands, let me see your hands. reporter: then she pulled the trigger twice. i asked god for forgiveness and i hate myself every day i feel like i don t deserve a chance to be with my family and friends.