In La Palma, California, veteran cop Jim Engen and rookie detective Paul Bracciodieta set out to solve the 1974 cold case murder of Annie Ross. This crime has plagued police for decades, but Jim and Paul's bond leads to a promising break in the case.

With retirement looming ever closer, Arlington P.D. Detective Byron Stewart races to save his legacy on the force by solving his final case, the unexplained double homicide of an elderly Vietnamese couple left for dead in their apartment.

Austin P.D. Detective Lisa Morrill's life is changed forever when she's pushed to the brink of collapse, mentally and professionally, when the luck of the draw lands her three brutal homicide cases of young women back-to-back.