Which type of surveillance can include observing a target with technical devices?

Technical surveillance involves the use of electronic devices and technologies to monitor a target or environment. This can include various forms of monitoring such as audio recording, visual observation through cameras, and even internet activity tracking. The key characteristic of technical surveillance is its reliance on technology rather than physical presence, which allows for more discreet monitoring and can often cover larger areas or multiple locations without the need for personnel to be continuously present. This approach is especially useful in situations where maintaining distance is crucial or where gathering information through conventional means might be impractical or too risky.

In contrast, the other types of surveillance typically do not emphasize the use of technological devices. For example, fixed surveillance usually refers to static observation by personnel, while mobile surveillance involves individuals following a target in a moving fashion without the aid of technical devices. Covert surveillance also focuses on discreet human observation and may not primarily incorporate technical tools, although it could potentially overlap with some technical elements. Therefore, technical surveillance stands out as the type that specifically includes the application of technical devices for observing a target.