Sniper Zero (S01E09)

Don and his team must stop a sniper who goes on a killing spree in Los Angeles. Racing against time to find the sniper, Don calls in Agent Edgerton (guest star Lou Diamond Phillips), a senior Sniper Instructor from Quantico, to assist on the case, causing Charlie to feel insecure about his role as special consultant to the FBI. Feeling animosity towards Agent Edgerton at first, Charlie learns from him that human behavior could make his mathematical equations useless. Instead, Edgerton encourages Charlie to get inside the head of the killer. (iTunes)