Police dog

Police dog during training exerciseSwedish German Shepherds in action during demonstrations in Stockholm on National Day 2007A police dog is a dog that is trained specifically to assist police and other law-enforcement personnel in their work. Police dogs are often referred to by the term "K9", which is a homophone of "canine", a word that generally refers to dogs and dog-like animals.

In many jurisdictions the intentional injuring or killing of a police dog is a felony,[1] subjecting the perpetrator to harsher penalties than those in the statutes embodied in local animal cruelty laws,[2] just as an assault on a human police officer is often a more serious offense than the same assault on a non-officer. A growing number of law-enforcement organizations outfit dogs with ballistic vests,[3] [4] and some even go so far as to make the dogs sworn officers, with their own police badges and IDs.[1] [5] [6] [7] Furthermore, a police dog killed in the line of duty is often given a full police funeral.

Purpose and function
A Belgian Malinois of a police K9 unit.Police badge of a New York K9 officerRoles police dogs fill include:
 * Public order enforcement dog - The traditional image of a police dog is one used to enforce public order by chasing and holding suspects, or detaining suspects by the threat of being released, either by direct apprehension or a method known as Bark and Hold. German Shepherd Dogs and Belgian Malinois are most commonly used because of their availability (see List of police dog breeds); however other dog breeds have also contributed, such as Dutch Shepherds, Rottweilers, Boxers, Doberman Pinschers, Giant Schnauzers, American Pit Bull Terriers, and American Staffordshire Terriers.
 * Search and rescue dog (SAR) - This dog is used to locate suspects or find missing persons or objects. Bloodhounds are often used for this task.
 * Detection dog or explosive-sniffing dog - Some dogs are used to detect illicit substances such as drugs or explosives which may be carried on a person in their effects. In many countries, Beagles are used in airports to sniff the baggage for items that are not permitted; due to their friendly nature and appearance, the Beagle does not worry most passengers[10] . Some dogs also are naturally able to sniff out propane leaks and may be used in the future. The Bouvier des Flandres is one breed that is able to do this. One pet Bouvier sniffed out a propane leak in the owner's grill.
 * Cadaver dogs - Some dogs are trained in detecting the odor of decomposing bodies. Dogs' noses are so sensitive that they are even capable of detecting bodies that are under running water[11] Pioneering work was done by Dr. Debra Komar (University of Alberta) in Association with the RCMP Civilian Search Dog Association in this area. The result was the development of training techniques that resulted in near 100% accuracy rates.[12] Her research has been published in the Journal of Forensic Anthropology.

 