The stakeout is an honored police tradition, and the setting for any number of television and movie scenes. Stakeouts most quickly come to mind when cops talk about surveillance, and most stakeouts are pretty low-tech. A pair of binoculars, a car or van, and a steady supply of bad coffee is all the hero requires to get his (or her) man.
Of course, in the movies, the bad guy never goes out the back door, is always immediately recognizable from everyone else in the neighborhood, and well-intentioned patrol cops don't notice the suspicious person watching the premises. Also no one ever has to go to the bathroom, and the word "hinky" will be used at least once.
Modern surveillance techniques still use the old methods, but technology can make the process both easier and more likely to yield good results. Sometimes it's not necessary to keep a watcher on site at all. Fixed surveillance video cameras never get sleepy, and video analytics software can help separate the interesting parts of the recording from the hours where nothing moves. The most significant problem with cameras isn't technical, though. It's finding someplace to put them.
Location, Location, Location
In a high-crime area, a permanent or semi-permanent camera on a utility pole or other support may deter the bad guys, but it's not often you have a great mount point right where and when you need it. This problem isn't restricted to local law enforcement.
The U.S. Border Patrol is often hampered by land use rules when they need to shift surveillance to a newly active border segment. Even when the land where the surveillance is needed is under federal control, the USBP doesn't necessarily have the clearance to move their equipment in. Much of the frontier is managed by the Departments of the Interior or Agriculture, and by the time their bureaucracies have reviewed the request and determined there is no adverse environmental, cultural, or historical impact, the border activity has shifted and the surveillance there is no longer valuable.
The surveillance system itself may become a crime target. Cameras and their associated hardware are prime vandalism and theft targets. The cameras generally point in a single direction. If the thief approaches from another area, he's free to take his time removing and/or destroying the camera. This was a story line in the cable series "The Wire." A detective placed an expensive wireless surveillance camera at what he thought was a hidden location. The camera was stolen, and he had to compromise himself to get it back and avoid heat from his superiors.
The automated license place recognition (ALPR) systems that are so popular right now are another form of surveillance technology. These systems are best known for identifying stolen vehicles, scofflaws, and other license plates of interest contained in their onboard databases. But used passively, they can simply record every license plate that comes in view of their cameras, noting the time and place of the recording. This data can be analyzed later to establish or confirm alibis and place suspect vehicles in the area of a crime, even though the crime was unknown at the time the record was made.
Moving surveillances, where the desired information is in where the target is and is going, is a combination of art and science. When traffic is light and the target is unsuspecting, it's easy to pull off. If the target is skilled in counter-surveillance, traffic is dense, or you don't have enough people and vehicles, it's a huge headache. Global positioning satellite (GPS) technology isn't new, but advances in the size, endurance, and cost of the hardware make it an attractive alternative to the traditional "tail."