In the shadowy and often misunderstood world of criminal activity and terrorism, hostile surveillance is one of the least understood elements. The goal of this article is to break it down in simple, practical terms — and to explore how security professionals can better spot and mitigate it.

While surveillance can cover a wide range of activities, including high-tech electronic monitoring, this piece focuses on HUMINT-based physical surveillance — in plain language, that means:

“The covert observation of a target for the purpose of collecting information.”

That short definition packs in the three essential ingredients of surveillance: covertness, physical observation, and information collection.

Take away any one of those, and it’s no longer surveillance.

  • If someone is observing openly, letting the target (or anyone else) see them, that’s just regular observation.
  • If they’re so well hidden that they can’t actually observe anything, they’re just hiding, not conducting surveillance.

The trick — and the challenge — lies in doing both at once: watching closely while remaining invisible. And of course, the whole point isn’t to pass the time. It’s to collect critical information that will help plan an attack.

How Hostile Surveillance Actually Starts

Operational surveillance doesn’t begin when someone sets eyes on the target. It starts earlier, with an operative quietly moving through the area to get a feel for its rhythm and routine — who’s around, how they move, what “normal” looks like.

Their first real goal is to find a good vantage point: a spot that gives them a clear view of the target while keeping them out of sight. A strong vantage point offers plenty of visual information while letting the operative blend in seamlessly.

But here’s where many people get it wrong — a skilled operative won’t just plop down at that vantage point right away. If they don’t fit into the environment, they’ll stand out, and their cover will be blown before the real work even begins.

So before taking the primary vantage point, the operative will first observe the observers’ spot — a “vantage point on the vantage point.” This second location ideally doesn’t even face the target, meaning the target can’t see them either.

Let’s say the vantage point is a park bench a block away. The operative first studies who typically sits on that bench, what they look like, and how they behave. If it’s mostly homeless individuals, the operative will adopt that cover — dressing, behaving, and moving like they belong there. Only then do they actually occupy the bench and begin active surveillance, all while appearing to be just another background character in the landscape.

Why “Looking for Suspicious People” Doesn’t Cut It Anymore

I’ve lost count of how many times experienced security and law enforcement professionals — people who’ve been around the block — are surprised when I tell them they can’t just rely on spotting someone who “looks suspicious” or “out of place.”

That’s one of the first things a well-trained surveillance operative learns: how to blend in perfectly. That’s what I was trained to do, and there’s no reason to assume hostile actors won’t do the same.

I’m not saying every surveillance operation is carried out at a professional level. But if you want to prepare seriously, you can’t just plan for the easy cases. You need to understand what the worst looks like — because it does exist.

Throughout history, many intelligence services have trained people to conduct surveillance at this level. Agencies like Ministry of Intelligence of the Islamic Republic of Iran, Inter-Services Intelligence (ISI), KGB, Stasi, and others have produced operatives who’ve gone on to support or enable terrorist activity through sophisticated surveillance work.

So What Do You Look For?

Once you accept that not all hostile surveillance can be spotted just by finding someone who looks “off,” the natural next question is: Okay, then what should we be looking for?

That’s exactly what the next article in this series will dive into.

In the meantime, if you want a deeper, behind-the-scenes look at real-world surveillance detection and covert operations, check out my book Surveillance Zone. You’ll get a first-hand account of actual operations, the tradecraft behind them, and the hidden world most people never notice — even when it’s happening right around them.

Get my new espionage thriller, Ghost Echo – on Amazon, December 15th.