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The Different Types of Surveillance Methods Used by Private Investigators

Surveillance covers many areas of investigation and new techniques have become available as technology has advanced. All these techniques used in combination have to give the edge to the private investigator versus someone off the street with no experience of how all these methods can be used in achieving justice.

People often consider the use of private investigators in a matrimonial or relationship scenario, but the private and personal world encompasses many more reasons why a private investigator may be needed, says David Kearns, MD of Expert Investigations Ltd. Having been at the forefront of private related investigations for 22 years one of the most common issues Kearns has investigated is cruelty, neglect and abandonment of children and their welfare.

For some help in this area, you might want to consider private investigators Denver as a firm experienced in locating people.


The majority of computer surveillance tends to involve the monitoring of data and traffic on the internet. For instance, in the US, phone calls and broadband internet traffic is available to federal law enforcement agencies. It is also there for those in the know to make use of. Many private investigators are ex-law enforcers and so have the contacts, knowledge, expertise, and permissions to access systems that the average individual would not.

The kinds of information available in this area will include emails and messaging, which will all provide a clue as to who is associating with who and reveal someone’s location, for instance.

Telephones and Mobile Phones

The official and unofficial tapping of telephone lines are carried out a lot in the US by those with expertise in this area.

With mobile phones, tracker devices can be by way of an app installed. There is no doubt that the ability to track someone’s every movement is invaluable when it comes to gathering location intelligence.

With mobile phones, a technique referred to as multilateration is used to perform a calculation of the difference in time a signal will take to travel from a person’s cell phone to a cell tower near them. This is an aid to tracking someone’s location. Mobile carrier antennas will also be used to gather geolocation data from mobile phones.

Global Positioning Systems (GPS)

Typically, in the US, police will use hidden GPS devices that have been planted in vehicles to track and monitor the movements of suspects. No warrant is required for these. This demonstrates how useful GPS is in law enforcement, which is something that mobile phone technology is now helping private investigators with.

Geolocation devices are useful for tracking down those that are trying not to be found but have no idea that it is a technology that will find them in the end.


Surveillance cameras will be used to survey an area as a camera can be carried to a location to take pictures from that position. With video technology, moving images are possible to be captured as well as still shots. These come with high-definition clarity now, so there is no mistaking someone when they are up to no good. The camera does not lie, so there is no chance of anyone disputing the evidence of their indiscretion or criminal activity.

Wireless devices make the camera and sound recording device concealment easier. Just because there is no wire, does not mean that someone is not being recorded in some way.

Long lenses allow surveillance to happen from a distance. But then, there is not always a need when CCTV is capturing itanyway and these images are obtainable. Private detectives, to capture everything, are prepared to be on the job during any 24/7 period, and anywhere in the world, so that the all-important images of those they are following will be capturedand then accessible to them and their clients. A camera will be used that is capable of taking multiple photographs in quick succession so that none of the action is missed.

Human Operatives

There cannot always be a substitute for having someone on the ground, whether that’s an individual or a team who conduct their own surveillance from a distance on behalf of an individual. This would have to happen at some point anyway if something like process serving was to take place. It can also be the best way to have informants hand over the information that they know. Some will be wary of technology and private investigators have to find different ways to deal with different types of people who can help with or are involved in their case.

RIFD Tagging

Microchips can be planted in the human body. These will be in the form of an RIFD or identifying integrated circuit device. It will be encased within silicate glass. Subdermal implants will generally contain unique ID numbers that will be linked to information that is stored on a computerized database. This can be as extensive as to include medical details and contact information. This is an advanced technology and is open to law enforcement agencies at least.


This technology will measure and provide analysis with regards to the physical characteristics of humans, among other things. So, this covers fingerprints, DNA, as well as facial patterns. It may be that a private investigator can gather this evidence and have access with regards to getting the analysis done. Either way, it makes evidence that is gathered useful in that there is a way it can be linked to a human suspect or guilty party, for whatever reason it needs to be.

So, some thinking on surveillance here, to give you some idea of the techniques that private investigators will use to find people and serve legal documents upon them. Hire private investigators for their superior knowledge of surveillance. It is one of the areas that they can help you most with.

Law enforcers, of course, use these surveillance techniques to make an arrest, and many of those go on to be private investigators. This is what provides the private investigator with their skills and experience of surveillance techniques.