NBC 'Dateline" Which co-worker killed popular woman in "Mystery on the early shift"?

(Dateline NBC)

NBC "Dateline" A popular co-worker is bludgeoned to death in a business warehouse. There were only 13 co-workers in the warehouse when Michelle was killed. It was 5:53 a.m. One by one, each co-worker was cut to a main suspect. Lie detectors were brought in & detectives found on a security camera, a truck leaving 30 minutes after the murder. Which co-worker owned that truck & why did he return to crime scene? 

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