In Evidence, a group of bus passengers become stranded at an abandoned gas station in the California desert. As night falls, they are attacked by an unknown assailant who begins picking them off one by one. In the aftermath of the massacre, detectives Reese and Burquez are tasked with piecing together what happened and identifying the killer.
To do so, they must analyze various recording devices found at the scene including security cameras, cell phone footage, and dashboard cams. As they review the footage, they begin to uncover a complex web of relationships and motivations among the passengers.
The detectives also encounter a group of scientists who were conducting an experiment in the area, leading them to question whether the massacre was the result of a scientific experiment gone wrong.
As the investigation progresses, Reese and Burquez race against time to catch the killer before they strike again. But as they close in on the truth, they realize that the killer may be much closer than they ever imagined.