A few years back, my neighbor found a small sticker plastered right next to her deadbolt. It said “24 Hour Locksmith” with a phone number she didn’t recognize. She peeled it off, tossed it in the trash, and forgot about it. Two weeks later, someone broke into her house while she was at work. The police told her the sticker was likely a marker. Someone had already scoped out her locks, decided they were easy to beat, and left a little note for themselves (or their crew) to come back later.
That story stuck with me. And the more I looked into it, the more unsettling the whole thing got. Burglars don’t just randomly pick houses. Many of them case neighborhoods for days or weeks beforehand, and they leave behind small, easy to miss signals near your front door. If you know what to look for, you might catch them before anything happens. If you don’t, well, you’re basically a sitting duck.
The Locksmith Sticker That Isn’t From a Locksmith
This one is the creepiest to me, because it hides in plain sight. In some areas, organized criminal networks send out scouts to walk through neighborhoods. Their job is to check your door hardware, peek at your locks, and figure out how easy it would be to get inside. If your home looks like an easy target, they slap a small sticker near the lock. It usually says something like “24 Hour Locksmith” with a phone number.
Here’s the thing: these aren’t lone wolves. These are organized operations. The scouts do their thing, marking houses across a neighborhood, and then professional thieves circle back weeks or even months later to actually do the break-ins. Police in the UK have confirmed a direct connection between these stickers and skilled burglary attacks. And while it’s harder to prove in the U.S., locksmiths in cities like Naples, Florida have reported seeing hundreds of these stickers on doors and locks around town.
If you find one of these stickers on or near your front door, remove it right now. Then go check if your locksmith is listed with ALOA (the Associated Locksmiths of America). If the number on that sticker doesn’t check out, assume the worst.
Chalk Marks, Tape, and the “Da Pinchi Code”
Yes, that’s actually what it’s called. There’s a whole system of chalk symbols burglars reportedly use to communicate with each other about which houses are worth hitting. An “X” might mean “this one looks easy.” A rectangle could mean “skip it, they have a dog or a security system.” Other marks might indicate whether a homeowner lives alone, whether the house has anything valuable, or whether it’s already being watched.
Police in San Marino, California actually warned residents about this. Officers noticed chalk marks appearing on sidewalks near certain homes, and they urged people to photograph the marks and report them.
Now, some people argue this is more urban legend than real threat. Fair enough. Chalk on a sidewalk could easily be from kids playing or a utility crew marking lines. But here’s the thing: in Dublin in 2018, police identified a tactic where burglars placed clear tape over keyholes on front doors. If the tape was still there a couple days later, the burglars knew nobody was home and the house was vacant. That’s not an urban legend. That’s documented.
White and blue spray paint marks are also common. Chalk is preferred because it washes off easily and doesn’t draw attention the way spray paint does. If you see unexplained markings on your mailbox, fence, sidewalk, or front wall, take a photo and wipe them away. Then check with your neighbors to see if they’ve spotted anything similar on their property.
Random Objects on Your Porch Are Not Always Random
Rocks on your porch step. A piece of string tied to your railing. A bottle sitting next to your door. A flyer from a business you’ve never heard of. These all seem like nothing. And most of the time, they are nothing. But burglars sometimes use ordinary objects as markers to test whether you’re paying attention.
The flyer trick is a good example. Someone slips a fake flyer into your door. If it’s still there three days later, that tells them you haven’t been home. Some burglars move patio furniture slightly, or place a small object near a doorway, just to see if it gets moved back. If everything stays exactly where it was for days on end, your house starts to look empty and vulnerable.
According to one source, 34% of burglars enter through the front door. That’s the single most common entry point. So anything unusual appearing right at your front door deserves more than a passing glance.
Scratches Around Your Keyhole Are a Huge Red Flag
Let’s say nobody breaks in, but someone tried. How would you even know? One of the biggest giveaways is scratches or tool marks around the keyhole. When a burglar tries to pick a lock, they insert a thin pick or flat screwdriver and work the pin tumblers until they catch. This almost always leaves tiny scratch marks or shiny spots on the metal around the keyhole that look different from the normal wear your key produces.
Lock bumping is even sneakier. It involves inserting a specially crafted “bump key” into the lock and tapping it with a small mallet. The force makes the pins jump, and the lock turns right open. If it’s done roughly, you’ll notice fresh nicks and shiny metal edges around the keyhole. If it’s done well, you might not notice anything at all, which is exactly why it’s so popular with criminals.
Here’s a stat that should make you uncomfortable: about 90% of homes in the U.S. have standard cylinder locks that can be bumped. If your locks are relatively old, came with the house, and use a single key, you almost certainly have one. And only 35% of home invasions show signs of forced entry. That means in the majority of break-ins, the burglar got in without kicking down the door or smashing a window. They just opened it.
Small Drill Holes Are the Worst Sign of All
If you see small, perfectly round holes near or around your lock, someone has been drilling it. This is an aggressive technique where a burglar drills into the lock to destabilize the cylinder, then simply knocks it out of the door. If you can see through the hole, it was almost certainly made by a drill. Some burglars drill right on top of the keyhole to destroy the cylinder entirely. This is not someone testing the waters. This is an active attempt at entry, and if you spot it, you need to replace your locks that same day and file a police report.
What to Actually Do About It
So you’ve found a weird sticker, or chalk marks, or scratches around your keyhole. Now what?
First, change or upgrade your locks. This isn’t optional anymore. The Schlage B60 series deadbolt is ANSI Grade 1 (that’s the highest residential rating), is pick and bump resistant, and costs around $30 at most hardware stores. You can install it yourself in under 10 minutes with a Phillips screwdriver. The Kwikset 980 is another solid choice with BumpGuard technology and a lifetime warranty. Both are available at Home Depot, Lowe’s, or Amazon.
If you want something even tougher, the Schlage B560 has a 6-pin cylinder with anti-pick pins, an anti-pry shield, and a hardened layer to resist drilling. It uses 3-inch screws in the strike plate to resist kick-ins. It also installs in about 10 minutes.
For when you’re home, a Defender Security Lock is a simple device that prevents forced entry from the outside. It has no key and works purely as a barricade. It’s pick-proof and bump-proof because there’s nothing to pick or bump. It just holds.
Beyond locks, here are the basics that actually work: motion-activated flood lights (a former burglar cited motion lights as one of the two biggest deterrents, the other being dogs), visible security cameras at all entry points, a video doorbell, and plug timers that switch lamps on and off to make your home look occupied when you’re away.
FBI crime stats put the average loss per burglary at around $2,661. A good deadbolt costs $30. A motion light costs $25. A video doorbell costs maybe $100. The math here isn’t complicated.
Don’t Write It Off as Paranoia
Look, I get it. A chalk mark on the sidewalk is probably just a chalk mark on the sidewalk. A sticker near your door is probably just junk marketing. Most of the time, the weird object on your porch blew in from a neighbor’s yard. But a burglary happens every 23 seconds in America. That’s about 3,757 per day. And the people committing them are not impulsive idiots. Many of them scope, mark, and plan before they ever touch your door.
The cost of being wrong about a chalk mark is zero. The cost of ignoring a real warning sign could be everything you own. Check your front door tonight. Look at the lock, the frame, the area around the keyhole. Check your mailbox and your porch. If something looks off, trust your gut. And then go buy a better lock.
