Most people picture surveillance as someone sitting in a parked car with binoculars. Part of the job is exactly that — but good surveillance is mostly planning, patience, and documentation. This is how professional investigators actually run a surveillance case, from the first conversation to the report you can hand to an attorney.
The main types of surveillance
- Static surveillance: watching a fixed location — a home, workplace, or business — from a position with a clear line of sight, documenting who comes and goes and when.
- Mobile surveillance: following a subject by vehicle as they move between locations. This is the hardest skill in the job and where experience shows most.
- Foot surveillance: following on foot in shopping centers, downtown areas, or anywhere a vehicle can’t go.
- Multi-investigator surveillance: two or more investigators coordinating so the subject never sees the same face or car for long, and both exits of a location can be covered.
Most real cases combine these: static coverage at the starting point, mobile coverage once the subject leaves, and foot coverage at the destination.
Step 1: Planning before anyone goes into the field
A surveillance case is won or lost in planning. Before fieldwork starts, investigators typically gather:
- A recent photo of the subject and a description
- Vehicle make, model, color, and license plate
- Home and work addresses and known regular stops
- The time windows that matter most to the client
- What, specifically, needs to be documented — and what the evidence will be used for
Investigators also scout the location: where they can park legally with a view, how many exits a property has, and which direction the subject is likely to drive. This is also when the legal boundaries get checked — what’s in public view, and what isn’t. (See what private investigators can legally do in California.)
Step 2: Techniques in the field
Positioning
The goal is a clear line of sight without being the obvious car parked in the same spot all day. Investigators choose positions that look natural for the area, adjust as the day goes on, and avoid lingering where residents would notice a stranger.
Blending in
Ordinary, common vehicles and everyday clothing matter more than anything you see in movies. The best surveillance vehicle is one nobody remembers.
Following in traffic
Mobile surveillance means staying close enough not to lose the subject at a light, but far enough not to be noticed — often with one or two cars in between. Experienced investigators anticipate turns, freeway exits, and signal changes rather than reacting to them. When the subject is lost, they don’t panic or drive erratically; they check the likely destinations and pick up again.
Patience
Much of surveillance is waiting. A subject may not leave the house for hours, or may run ordinary errands for most of the day before the activity that matters happens. That’s why knowing when to watch matters so much — in infidelity cases, the client’s own observations usually point to the right window. See the signs of a cheating spouse.
Step 3: The equipment investigators use
- Cameras with zoom lenses for clear photos and video from a distance, in public view.
- Video cameras that capture long, continuous footage with accurate date and time stamps.
- Low-light capable equipment, since a lot of surveillance happens in the evening.
- Logs and notes — written or digital — recording every observation as it happens.
Just as important is what professionals don’t use: GPS trackers on vehicles the client doesn’t own, recording devices that capture private conversations, or anything that involves accessing someone’s phone or accounts. Those methods are generally illegal in California and make evidence unusable.
Step 4: The surveillance report
The report is what you’re really paying for. A useful surveillance report usually includes:
- Case details: dates, hours of surveillance, and investigators involved
- A chronological log of observations with exact times and locations
- Still photographs pulled from the video at key moments
- The video files themselves, with an unbroken record of where they came from
- A plain-language summary of what was and wasn’t observed
Here’s what a timeline entry in a report typically looks like. This is an illustrative format only, not from a real case:
5:42 PM — Subject exits the office building on the east side and walks to a silver sedan in the public lot. Video recorded.
5:47 PM — Subject departs the lot heading north. Investigator follows.
6:15 PM — Subject parks at a restaurant and enters with a second person. Photos taken from the public parking area.
Good reports describe what was observed, not what the investigator assumes it means. That’s what makes them credible to an attorney or a judge.
Step 5: Using surveillance evidence in court
In family law, civil cases, and insurance matters, surveillance evidence has to be authenticated — someone has to establish when, where, and how it was captured. That’s why consistent time stamps, detailed logs, and careful handling of video files matter. If needed, the investigator can testify to what they observed.
How long does surveillance take?
It depends on how predictable the subject is and what needs to be documented. Some questions are answered in a single well-timed evening. Others, like showing a pattern in a custody case or comparing activity against a workers’ compensation claim, take several days spread over weeks. A good investigator will tell you up front what’s realistic.
Surveillance with Bear Witness
Surveillance has been Bear Witness’s core specialty since 1996. Every case is planned around the subject’s real routine, run by a licensed California investigator (PI License #18755), and documented to the standard courts expect. Learn more about our surveillance services, or find an investigator near you — for example in Los Angeles, Irvine, or San Diego.
Frequently Asked Questions
- How do private investigators follow someone without being noticed?
- By planning ahead, using ordinary vehicles, keeping a car or two between them and the subject, anticipating turns, and often working in teams so the subject never sees the same car for long.
- What equipment do private investigators use for surveillance?
- Mainly cameras with zoom lenses, video cameras with accurate time stamps, low-light capable equipment, and detailed observation logs. Professionals avoid illegal tools like hidden vehicle trackers or audio bugs.
- What is in a private investigator’s surveillance report?
- Case details, a time-stamped log of observations, still photos, the video files, and a plain-language summary of what was and wasn’t observed.
- Can surveillance evidence be used in court?
- Yes, when it is gathered legally and documented carefully so it can be authenticated. Investigators can also testify to what they observed.
- How long does private investigator surveillance take?
- Anywhere from a single evening to several days spread over weeks, depending on the subject’s routine and what needs to be documented.
Have questions about your situation? Call 1(877)PROOF-24/7 for a free, confidential consultation with a licensed California investigator.