There have been documented cases of motorcycle police officers from as early as 1908 in Detroit, Michigan, when they reportedly ordered the first police specific motorcycle. Over the years, most metropolitan police forces have continued to maintain a motorcycle police presence, especially in the large, high population area. During the 1930's, motorcycle police became a more stable part of law enforcement, but it was during World War II when cheap transportation was needed that they really took off.
Motorcycle police have been around for more than a century; however, as more and more urban areas increase in traffic and population density, they are quickly becoming the go to vehicle for many metropolitan law enforcement agencies. Because of this, there are a number of different motorcycle manufacturing companies that are working to make motorcycles that can specifically handle this type of driving and have been modified to fit different police department needs. For example, if the primary use of the bike is going to be for parking violations, then they might make a scooter, while for country areas, they might need a vehicle with off-road capabilities. Different police motorcycle units have different motorcycle patches on their clothing to signify what station they are associated with.
More and more countries are embracing the motorcycle policeman role as well, and as populations around the globe continue to grow, it is likely that this will become a preferred method of transportation for urban areas worldwide. Since motorcycle manufacturers work with police departments to design bikes to fit their needs, it's likely we'll see new models designed for law enforcement, as well.