If you have spoken to a security camera installer about deterrence, you have likely heard the claim that visible cameras prevent crime. This is partly true and meaningfully incomplete.
The research on CCTV effectiveness shows that the relationship between camera installation and crime reduction is real but conditional — dependent on camera placement, crime type, lighting, and whether cameras are monitored in anything like real time. Understanding these conditions helps you install cameras that actually work as deterrents rather than just documentation tools.
What the Evidence Supports
A 2022 systematic review published in the Journal of Experimental Criminology examined 80 studies on CCTV and crime. The findings were broadly consistent with earlier reviews: CCTV reduces crime in specific contexts, primarily in car parks and public transit settings, with more modest effects in residential areas. The deterrence effect is stronger when cameras are combined with other security measures — lighting, physical access controls, and visible security presence.
For property crime specifically — vehicle break-ins, package theft, property damage — visible camera placement at predictable entry and exit points has a measurable deterrent effect. Opportunistic criminals conducting a fast assessment of a property are more likely to choose a target without visible cameras.
What the Evidence Does Not Support
CCTV has a weak deterrent effect against premeditated crime, crimes committed under intoxication, and domestic incidents. A camera did not prevent the crime; it documented it. This is not worthless — evidential footage has real investigative value — but it is different from deterrence.
Camera signage without functioning cameras produces some deterrent effect in low-sophistication crime contexts. Against more experienced offenders, fake cameras are identified and ignored. This is a specific risk with low-cost deterrent setups.
The Displacement Question
A consistent finding in the criminology literature is that cameras in one location can displace crime to adjacent unmonitored areas rather than reducing it overall. For a neighbourhood or commercial district, this matters for public policy. For a homeowner, the practical question is whether your specific property becomes a lower-priority target than an unmonitored neighbouring property — which is frequently yes. This is rational self-protection even if it is not a community-level solution.
Placement for Maximum Deterrent Effect
Deterrence is maximised when cameras are visible enough for an approaching person to see them during the decision window — typically as they assess an approach to a door or vehicle. A camera mounted at four metres pointing downward at a steep angle may be technically superior for coverage but is less visible as a deterrent than a camera at 2.5 metres with a visible housing.
Lighting matters. An infrared camera in a dark entryway captures footage, but a person approaching cannot see the camera housing clearly. A visible camera under a working exterior light is a better deterrent configuration even if the camera’s technical specifications are identical.
The Honest Case for Installation
Security cameras are a meaningful deterrent for opportunistic property crime. They produce evidence with investigative value when crimes occur. They allow remote monitoring that has practical daily-use value beyond security — checking for deliveries, verifying contractors, and monitoring for hazards.
Presenting cameras as a guarantee against crime, or as a substitute for other security measures, is inaccurate. As one component of a layered approach — good lighting, secured entry points, visible deterrents, and appropriate monitoring — cameras are a worthwhile investment. On their own, they are useful but limited.
Knowing this going in allows you to position cameras for both evidence collection and deterrence visibility, rather than optimising only for documentation. Those are different placement decisions.