In small-town bartow, florida four bodies are found slaughtered in a factory. It’s the largest mass murder in county history. Each victim is somehow connected to the factory and the family business -- and each victim seems to have been executed by a professional assassin. When investigators finally zero in on a prime suspect, they are foiled by his picture-perfect alibi – security footage showing him 500 miles from the scene of the crime. With no hard evidence in sight – and with the bloodthirsty killer still on the loose – investigators turn to video forensic analysis, complex timeline reconstruction, and a most unexpected 3-year-old fingerprint.