The purpose of this thesis is to generate a tactical decision aid (TDA) capable of calculating the probability of kill of a submarine when targeted with a vertical launched (VLA) anti-submarine rocket propelled torpedo (ASROC). In determining the submarine specific probability of kill (Pk), the Passive Contact Tracker and Kill Probability (PACT-AKP) TDA will calculate the submarine's position and its area of uncertainty (AOU) based on single or multiple ASW passive sensor bearing-to-target inputs. In determining the target's position and AOU, PACT-AKP employs an extended Kalman Filter that uses MTST movement and measurement models. In calculating ASROC probability of kill, submarine specific torpedo specific effectiveness (TEFF) data collected from NUWC Newport was used to generate the Pk algorithm. We can conclude that PACT-AKP not only assists the ASW team with target motion analysis (TMA), but also provides the commander with a credible target probability of kill prior to the employment of VLA ASROC torpedoes as a deliberate attack weapon. Approved for public release; distribution is unlimited. Outstanding Thesis US Navy (USN) author. http://archive.org/details/probabilityofkil109454820