Investigation and Security Blog

Four types of surveillance explained

surveillance-camera-icon The objective of your surveillance will determine what method is employed.

For investigative agencies, surveillance is categorized into either physical or electronic. Physical surveillance entails putting "eyes on" a subject, and observing that person's locations, movements, and actions.Electronic surveillance employees a variety of devices to monitor the subject.Whether physical or electronic, each method can also be further classified as overt or covert.

These techniques are often blended to provide a more comprehensive picture of the subject's activities. For example, covert physical surveillance may be supported by an electronic tracking device to avoid losing the subject when moving from location to location. If you need to employ surveillance as part of an investigation, the goal of the surveillance should be defined: by watching this subject, what are you hoping to learn.As much information as possible about the subject should be provided to the surveillance team prior to beginning the surveillance. This includes known locations of the subjects, daily patterns, and known associates. This allows the team to better anticipate the subject's actions, conducting a more effective operation at the time when it is most likely to collect the desired information. 

Covert physical surveillance: The objective of this type of surveillance is to learn what the subject is doing during his/her normal course of activities. Avoiding discovery is the priority in order to avoid alerting the subject and causing the person to alter their actions. This is what people normally picture when thinking of investigative surveillance. A detective or two, sitting in a vehicle for an extended period, watching from a distance and waiting for something to happen. When watching or waiting for the subject from a fixed location, this is known as static surveillance. A surveillance can remain static for hours or in some cases days. Once a subject moves from one location to another (usually via auto), the surveillance becomes dynamic, and the surveillance team moves along with the subject to the next location. A variety of tools such as binoculars, zoom lens cameras, and night vision may be employed to allow the team to operate from a distance to avoid being detected. Depending on whether the "team" is a single investigator or several members, techniques will be used to minimize exposure of each member to avoid discovery by the subject.

Overt physical surveillance: The objective of overt surveillance is to let people know an individual or location is being watched.Instead of collecting information, overt surveillance provides a level of protection or prevention. If a residence or business is under surveillance, it is less likely to be burglarized.Intelligence services will sometimes overtly surveil a suspected spy in order to prevent that individual from conducting an illegal espionage act.

Overt electronic surveillance: We see this everywhere – closed circuit video cameras in stores, gasoline stations, airports, etc.Anytime you are in a commercial location, look up and you may see multiple cameras with a view of you. Other common types of overt surveillance include license plate readers, X-ray devices at airports and shipping ports, and speed cameras. Similar to overt physical surveillance, this type of electronic surveillance is intended to protect or deter illegal or unwanted actions. People are less likely to do bad things when they know they are being watched (but not always!)

Covert electronic surveillance: Recording what people do during the normal course of their day is the objective of this type of surveillance. Hidden cameras and tracking systems are common methods of covert surveillance. There are also devices in plain sight that may be covertly recording activity, such as smartphones, Alexa devices, Nest devices, and newer television sets. All of these devices may be equipped with microphones to detect and record human activity. The laws governing the use of these methods vary from state to state, and in most cases require a court order or warrant when employed by a government agency.

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