Do Security Signs Actually Deter Burglars? The Evidence

What the UNC Charlotte burglar survey found

A widely cited piece of evidence for sign deterrence is a 2012 study, "Understanding Decisions to Burglarize from the Offender's Perspective," by Joseph Kuhns of UNC Charlotte with Kristie Blevins (Eastern Kentucky University) and Seungmug Lee (Western Illinois University). The team surveyed 422 incarcerated male and female burglars, selected at random from state prisons in North Carolina, Kentucky, and Ohio, about how they chose targets and what deterred them.

The headline findings, as reported by the university:

• About 83% of respondents said they would try to determine whether an alarm was present before attempting a burglary.
• About 60% said they would seek an alternative target if an alarm was on site. This was especially true of burglars who deliberately planned their burglaries.
• Among burglars who discovered an alarm mid-attempt, half said they would discontinue, 31% said they would sometimes retreat, and only 13% said they would always continue.
• When selecting targets, burglars reported weighing "signs of increased security," a category that included alarm signs alongside actual alarms, dogs inside, and outdoor cameras.
• Female burglars were more often dissuaded specifically by signs suggesting a location was alarm-protected.

Read carefully, this is primarily evidence about alarms, not signs. The survey asked what burglars would do about an alarm's presence; a yard sign is one way burglars infer that presence. The study does not isolate what happens when a sign exists without an alarm behind it, which is the question most people searching this topic are actually asking.

The survey's limits

Four limitations matter before building a security plan on this study.

It surveyed burglars who got caught. Every respondent was in prison. Burglars skilled or cautious enough to avoid conviction, plausibly the ones most attentive to security cues, are not in the sample, and the incarcerated may differ systematically from active offenders.

It reports stated intentions, not observed behavior. Answers to "would you seek another target if there was an alarm?" are hypothetical self-reports, collected years after the offenses. Stated deterrence and actual deterrence are not the same measurement.

Much burglary is impulsive. In the same survey, only about 12% of burglars said they typically planned in advance; 41% described their burglaries as spur-of-the-moment and 37% said it varied. A yard sign's deterrent logic assumes a burglar who is scanning, comparing targets, and making calculations. The survey's own data says a large share of burglaries do not work that way.

The funder was the alarm industry. The study was funded by the Alarm Industry Research and Educational Foundation, under the auspices of the Electronic Security Association, the alarm industry's trade association. That does not invalidate the findings, the methods and authors are academic, but it is context a reader deserves when the headline finding favors alarm ownership.

What victimization data shows: signals without substance do not protect

The strongest counterweight in the research covered here comes from asking a different question: not what burglars say deters them, but which homes actually get burgled. Tseloni, Thompson, Grove, Tilley, and Farrell analyzed 2008 to 2012 data from the Crime Survey for England and Wales, a large national victimization survey, and computed a Security Protection Factor for each security device and combination, published in Security Journal in 2017 as "The effectiveness of burglary security devices."

Their findings, from the paper's abstract:

• The most effective individual devices were external lights and door double locks or deadlocks.
• "Counter-intuitively, burglar alarms and dummy alarms confer less protection than no security."
• Combinations beat individual devices: combinations with door and window locks plus external lights or security chains conferred at least 20 times greater protection against burglary with entry than no security.

A dummy alarm is the closest studied analogue to a security sign without a system: a visible deterrence signal with nothing behind it. In this data it was associated with no protective effect at all. The authors are careful to note that further research is needed, and the alarm finding has plausible confounds (households often install alarms after being burgled, and alarm ownership correlates with other risk factors), which is why the honest reading is "no demonstrated protective effect," not "alarms attract burglars." Either way, the data gives no support to the idea that the signal alone, sign or dummy box, keeps burglars away. This matters for renters and budget setups weighing a $10 sign against real measures; the same logic applies to the fake-camera decals we cover in no-subscription security cameras.

What policing research recommends instead

The US Department of Justice's COPS Office funded a problem-oriented policing guide, Burglary of Single-Family Houses, maintained by the ASU Center for Problem-Oriented Policing. Its assessment of alarms is measured: "Most studies of burglars indicate that many will avoid residences with alarms, but alarm effectiveness has not been well evaluated." The industry-cited study it references (Hakim and Buck, 1991) found alarmed homes in three suburban areas faced a 1.4% burglary risk versus 2.3% without alarms, and the guide explicitly warns those findings should not be generalized.

The guide's stronger conclusions point away from signals and toward physical and behavioral measures: target hardening (sturdy doors with deadbolts, window locks rather than latches, secured sliding doors), occupancy indicators (lights on timers, cars in driveways, mail stopped during trips, dogs), and visibility (trimmed shrubs, motion-activated lighting). It stresses that "most research suggests it is the combination of responses that is effective," and it lists dummy alarms and warning stickers only as short-term measures for recently burgled homes, not as general prevention. Notably, it also finds that generic crime-prevention advice tends to be adopted by the lowest-risk households.

This converges with the victimization data: the measures with evidence behind them are the unglamorous ones, locks, lights, and making the home look occupied, applied together. Practical low-cost stacks built on this evidence are in home security for renters and the apartment door security checklist.

The honest bottom line

Putting the three bodies of evidence together:

• A sign probably filters some deliberate burglars. Self-report evidence says planners check for alarms and most would rather pick an easier target, and a sign is one of the cues they read. Signs cost almost nothing, so this weak, self-reported benefit comes nearly free with an alarm you actually own.
• A sign alone has no demonstrated protective effect. The victimization data covered here found no protection from dummy alarms, and burglar surveys say a large share of burglaries are impulsive, committed by people who were not reading yard signs at all.
• What measurably lowers burglary odds is the combination of basics: deadbolts and window locks, external and internal lighting, occupancy cues, and visibility. In the England and Wales data, combinations built on door and window locks plus external lights were associated with at least 20 times more protection than no security.

So: put up the sign if you have a system; it costs nothing and may help at the margin. Do not buy a sign instead of locks and lights, and be skeptical of any claim that signs alone "cut burglary risk" by a specific percentage; we found no study that supports such a number. Where a real alarm with professional response fits into the picture, and what it costs against these free and cheap measures, is the subject of is professional monitoring worth it and our monthly cost table.