PI 101: Surveillance Techniques Used in a Private Investigation



Surveillance is the stealthy observation of a person, place, or thing and is one of the methods used by private investigators and law enforcement agencies to confirm or deny allegations of illegal or suspicious behavior. Surveillance can be done in person or with the use of electrical devices to monitor conversations. It is also carries some risk. If a private investigator (PI) is detected in an area, his ability to return there will be compromised. Different types of surveillance can be used in a private investigation, and the best private investigators know which method is best suited to the individual cases.


Surveillance Used in a Private Investigation

  1. Mechanical Surveillance

This is the usage of electronic/ technological devices to conduct surveillance. The benefit here is that unlike people, equipment doesn’t get bored, hungry, or tired. Equipment can be used in more than one location at a time and has the ability to obtain information 24/7.

  • Electronic Monitoring. This involves surveillance of telephone, internet, fax, and email communications. However, in order for a private investigator to proceed, he will require a court order
  • Stationary Device Surveillance. This is when a PI uses recording equipment and a hidden camera in a parked vehicle. The car is normally stationed in an area that won’t draw too much attention, such as a parking lot. The device can sometimes be unmanned, while still recording images at any time. The fact that it does not require the PI’s presence helps decrease the chance of discovery, and the PI is also able to come and go as he pleases.


  1. Human Surveillance

This is when the private investigator himself is the main source of information. In other words, the PI is physically there observing and tailing targets in person.

  • The Stakeout. Also known as fixed surveillance. With this type of surveillance, the PI observes people or places from a distance. The PI can either be alone or with another investigator. Having two PIs on a stakeout is generally preferable, as one can rest while the other watches. Additionally, they are able to alternate positions, thereby reducing their chances of being spotted.
  • Three-Person Surveillance. According to Chron, this is also called the ABC method, referring to the PIs’ assigned roles. Person A remains behind the suspect, with person B following close by. Private investigator C generally stays across the street, constantly staying slightly ahead of or behind the suspect.


  1. Overt vs Covert Surveillance

This is in effect when people in a public place are aware that there is surveillance equipment. For example, people in a casino are aware that there are cameras recording to ensure there is no cheating or stealing.

Covert surveillance is the method generally used by private investigators. They tail or observe the individual without her knowledge, as long as the private investigator does not violate any state laws.


What Private Investigators Have to Keep in Mind

When using surveillance in a private investigation, PIs have to use all their skills and have to have certain qualities. Most PIs need a good memory, an outgoing personality, attention to detail, and great communication skills. They also have to have patience and be observant and resourceful.

  • Ethics and Laws. Information obtained from surveillance is often very sensitive. A good PI has to be fully aware of the laws in their state, particularly regarding trespassing, audio recording, and invasion of privacy. It is therefore the PI’s duty to know his legal limits and conduct the private investigation accordingly.
  • Involving the Authorities. Depending on state laws, a private investigator may not be obliged to inform the authorities of the nature of the investigation, or the individual the PI is investigating.


Professionals for Your Private Investigation

If you require a private investigator, Maya and Maya offer a wide range of private investigation services from missing persons to online dating investigations and everything in between. Our operatives are professional and have 10 years of experience in civil and domestic investigations. They are experts at surveillance and other methods of private investigating, but operate within the confines of the law while keeping our clients’ best interests in mind. Contact us today for a free consultation to find out how you can benefit from our professional services.