Police looked at security footage that went back as far as December, and it showed the car in the same spot.
Walmart officials said they do not have security patrolling the parking lot overnight, but have the 24-hour surveillance camera.
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Moss' cause of death has not been determined.
But her sister told KSBW that a suicide note was found and a drug needle was found in the car.
Police said Moss' death was probably a suicide.