Woman fatally shot outside PetSmart after dispute over not saying 'thank you': officials

Simpson allegedly became irritated that Hampton didn't thank her for holding the door open, triggering an argument. Simpson and her daughter went to their car and drove to PetSmart, which was in the same plaza.

When Simpson and her daughter entered the PetSmart store, she told employees they were being followed by Hampton. Hampton allegedly walked into the store and began arguing with Simpson's daughter. Hampton exited the store, but returned a few minutes later, when she allegedly started another argument with Simpson.

After being asked to leave the store, Hampton allegedly threw a bottle at the vehicle Simpson was driving with her daughter in it. According to police, a physical fight then ensued when Hampton took out a handgun and allegedly shot Simpson three times.

Hampton was arrested on Tuesday night during a traffic stop and admitted she got into an argument with Simpson, but claimed she only took out the gun when the situation became physical.

Hampton was booked into jail on a murder charge. Her bail hasn't been set.

An ER nurse who saw the incident told FOX 4 her perspective on what happened.

The nurse said she performed CPR before paramedics arrived.

"The daughter was next to the mom the whole time. It's hard, you know, because the screaming of a child for her mother is never easy and it's never going to leave my head," she said. "I've been trying not to cry, but just like, you know, being in high school, my mom was such an important person in my life and she's the reason I became a nurse. My whole family is."