Types of Surveillance in Criminal Investigations

Detective using camera undercover
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Police officers, detectives and undercover agents use surveillance for many different reasons. These men and women investigate criminals to protect the citizens of their jurisdiction and to acquire concrete evidence toward conviction. Surveillance methodology is a touchy subject, as some people believe it violates constitutional rights. Others feel it is a necessary means to a possibly dangerous end. Investigators use many different methods to survey criminal conduct. Each method has its own approach and uses.

Covert Photography


Photography is a common form of surveillance in criminal investigations. Police officers take photos of criminals from a hidden location or by following the suspect on foot. When watching an individual, the investigator must stay close enough to track the subject's movements but far enough to remain unnoticed. According to the book “Criminal Investigation” By Michael Palmiotto, “The key to this operation (stakeouts) is secrecy.”


Video is another useful method of tracking criminal behavior. Surveyors use small, hidden video cameras to record criminal actions. Video is often the best choice for surveillance. According to the book “Criminal Investigation” by Karen M. Hess and Christine Hess Orthmann, “A video cassette or DVD, played before a jury, can bring a crime scene to life and offers some distinct advantages over photographs such as showing distance and being cost effective.”

Undercover Infiltration

Many officers choose to gain access to the subject’s life by going undercover. The information acquired by an undercover agent can be the difference between an acquittal and a conviction, but, in many cases, undercover work has an adverse effect on the officer. When going undercover, officers integrate themselves into a criminal lifestyle. They must gain the trust of the suspect and prove their loyalty.

Read More: Undercover Investigation Techniques


Police use informants as a means to acquire information about a subject in question. When an officer goes undercover, they must gain the trust and respect of the person or organization under investigation. Most informants are involved with the suspect to begin with, giving them the ability to bypass many of the hurdles an undercover agent faces. Because most informants are criminals with known ties to the suspect, many people question the integrity of their information.



The use of wiretaps and other unauthorized forms of surveillance has become a controversial topic in recent years. Many people feel it is unconstitutional to observe an individual without his or her express consent. However, the government has implemented safety guards for such cases. Agents must get legal consent and the crime must warrant such forms of inspection. According to the Center for Democracy and Technology, “Terrorist bombings, hijackings and other violent activities are crimes for which wiretaps can be ordered.”

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