Chase Merritt stands trial for his life in the murder of the McStay family.

A witness and an alibi suggest Merritt may be innocent of the murders.

Police look at suspects, and video of a truck may reveal the killer.

The defense detects new DNA in the graves, and a key suspect goes missing.

Tension builds as everyone awaits the verdict, and a new suspect surfaces.

Merritt claims new proof confirms his innocence, and a key figure emerges.