Do police firearm arrests reduce later shootings in nearby locations and in the days immediately following the arrest? This question is examined at a more detailed level than in previous work in order to better describe the spatio-temporal dynamics linking these two event types. All firearm arrests (n = 5,687) and shootings (n = 5,870) in Philadelphia from 2004 to 2007 were analyzed using a modified close-pair method. Following a firearm arrest shootings declined significantly, 28-47% up to a couple of blocks away. These significant declines, however, lasted for just a few days. Overall, results suggest police firearm suppression effects occur, may extend up to two blocks away from a firearm arrest, but also are short-lived. Potential implications for deterrence are discussed.