Canines in law enforcement have come a long way from their humble beginnings and continue to evolve even today. Law enforcement uses K9s in ways never imagined only a few decades ago, and their innate ability to search for and locate hidden suspects during SWAT operations is an excellent example of that evolution.
K9s have proved to be a valuable tool in law enforcement. The key word is tool. Dogs are not perfect. They can make fundamental mistakes, based largely on their training. Their performance can sometimes be hampered by the environment in which they are deployed, causing them not to find people from time to time. But by far, the most common denominator in unsuccessful deployments is the K9 handler who simply misreads, or fails to recognize, a slight change in behavior in the dog while it is actively engaged in a search.