Security Hacks

15 Simple Ways to Find Out If Someone Has Been In Your House

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An open single hung window with a mug in front of it 

If you suspect that someone has been in your house (or apartment) while you’ve been away, and you want proof, this article is for you.

Apart from the obvious cases, such as most burglaries, it’s often pretty hard to tell if someone has secretly entered a dwelling.

Fortunately, there are some proven methods that you can use if you need to find out if any person has invaded your private space.

First, let’s see the telltale signs that you can find in hindsight without prior preparation.

FYI: In case of burglary (signs of forcible entry, valuable items are missing, etc.), call the police immediately and do not touch and move anything until they arrive.

1. Look for Traces Outside the House (or Apartment)

If you want to find out if someone has entered your house, the first thing you should do is to look for telltale signs outside the building.

Focus on the paths that lead to your front door, back door, and windows.

Whether you live in a house or an apartment, inspect the area in front of your door(s) first. Can you see soil residue or any type of dust or dirt that suggests that someone stepped on that area? Is everything in its original place? What about the doormat?

A muddy footprint on tile floorPin

If it’s winter and snow covers your yard, you’re in luck because you’ll be able to spot foreign footprints very easily.

Another favorable situation is if it’s a rainy day. If everything is wet outside it’s very hard to avoid leaving some muddy spots on the way to the door. Sometimes these traces are hardly visible, so you have to be very thorough while you’re investigating.

Now, check the grass around the house. Can you identify footprints on the lawn? Check whether there’s any area where blades of grass are bending. Again, focus on the paths that lead to your doors and windows.

2. Inspect the Door Lock and Jamb Carefully

As a next step, have a careful look at your door lock and jamb.

Pay special attention to the following areas:

  • keyhole and the surrounding area
  • doorjamb (especially at the level of the deadbolt)
  • exterior hinges
  • the functionality of the lock

Is there any visible sign that anyone has tampered with the lock?

Burglars often use bumping to open locks. It’s a pretty simple method that requires a special bump key and a tool that is used to tap on the bump key. It’s so easy to implement that even newbie burglars can do it.

Lock picking is another relatively simple way of gaining unauthorized access to a property.

Make sure there are no tiny scratches, fresh metal edges, new nicks, or any other unusual marks around the keyhole because these could be telltale signs of lock bumping or lock picking.

Unfortunately, experienced burglars will likely leave little trace when using the above methods, so again, you must be thorough.

It’s important to be proactive when it comes to security. For instance, if you have a bump and pick proof lock, you don’t really have to worry about the above scenario. You’ll find my best and most helpful tips on how you can improve your front door security in this article.

Next, check whether your doors are locked properly. If any of your door locks are open, and you know for sure that you’ve locked it, it’s a pretty obvious sign that someone has entered your home (or at least tried to).

Another important thing is to check whether your door lock works properly.

Is it hard or harder to turn your key than previously? If it is, it might be the consequence of lock bumping.

Now inspect the door frame and the jamb. Can you see any damage to them?

Look for:

  • signs of warping or drilling
  • bent or twisted deadbolt
  • fresh marks on the wood door frame

These signs make it likely that an unauthorized entry has taken place. Some burglars instead of applying sophisticated methods, try to get into homes using brute force techniques, such as kicking or jimmying the door open. These methods leave clearly visible marks on both the door and the frame.

Finally, if your door has exterior hinges, make sure to check for signs and marks that suggest that they’ve been manipulated. By the way, here I show you all the relevant methods to secure your exterior door hinges.

3. Inspect Your Windows and Curtains

Once you’re done with your doors, move on to the windows and check them for signs of intrusion.

The truth is, window locks are usually much easier to bypass than door locks.

Therefore, burglars often head straight towards a window and don’t even bother with the front door.

This is why it’s so important to inspect whether there’s any visible damage to your window locks and frames.

If your window is open (even if it’s open ajar) and you’re confident that you left it closed, chances are good that someone has been in your home.

To be honest, I’ve hardly ever seen a burglar that locked the window after they left the house. Therefore, if all your windows are closed and intact, it’s unlikely that anyone got inside through the windows.

Another thing you should pay attention to is the curtains. Intruders who get inside through a window more often than not also open the curtains and they usually leave them that way.

Partially open curtainPin

So open curtains can be a sign of intrusion, especially if the window is also open.

Windows are often the weakest point of home security. If you feel this is true for your home, click here to learn how you can secure your windows without using unsightly bars.

4. Look for Footprints Inside the Dwelling

If you think somebody has been in your house, think carefully about what you’re going to examine before you enter your home otherwise you may ruin the traces.

I suggest that you start with the floor in front of your door and work your way from there towards the interior spaces and rooms.

Look for visible and unusual footprints. That means, you have to exclude your own and your family members’ footprints, and that sometimes can be a little tricky.

Once you’ve found a footprint that looks suspicious to you, check if the size and the pattern match one of your own shoes.

Footprints are not equally visible on each type of floor, and if the weather is dry, you may not be able to detect any footprints at all.

5. Check the Position of Your Belongings and Items

In most cases, if a person secretly enters a home, they will move some objects from their original position and often leave with some valuable items (except when the reason for the intrusion is spying on you or when the unlawful entry is not associated with malicious intent).

The difficulty here is that you need to remember the exact position of your belongings and spot if something is missing.

A few items that you should check:

  • drawers
  • rugs and mats
  • closet and cabinet doors
  • books and documents (filing cabinet)
  • the position of your interior doors
  • jewelry
  • paintings and posters on the wall
  • pillows, cushions, mattress

The photo below shows a partially open drawer that suggests that someone may have been rummaging around in the room.

Partially open drawerPin

Is anything missing? Think of valuable items, private documents, jewelry, and cash in the first place. Go from room to room.

6. Search for Fingerprints On Dusty Objects

This is a pretty neat technique but it only works if there’s at least a thin layer of dust on most items in your home (the thicker the better). As it turns out, being lazy sometimes pays off.

An intruder will likely touch a bunch of items and even if they use gloves (so no fingerprint will be left), they will wipe the thin layer of dust off the surfaces of the items they touched.

And that’s a visible sign that will definitely help you tell if someone has been in your house.

To detect these signs you need to use a torch or turn on the flashlight mode on your phone and check those items that you think an intruder would touch at an angle where you can clearly see the dust particles.

Tip: Start the inspection with the bookshelf and pay special attention to the master bedroom and home office.

7. Check the Lights

Although it’s not common, an intruder may leave the lights on. When you get home, check the lights in each room and if you find one that’s on and you know that it wasn’t you who turned it on, look for other telltale signs.

Be careful, however, if you arrive home and notice that the lights are on in your house, as burglars may still be inside.

8. Ask the Neighbors

If an unauthorized person has been in your home, a neighbor may have some useful information.

Therefore, ask your neighbors if they’ve seen any suspicious activity around your house or in the vicinity.

I highly recommend that you join a local neighborhood watch group or start one if there isn’t any.

9. If You Have a Security Camera Installed, Check the Footage

This one speaks for itself. The only reason I mention it is because security cameras are usually clearly visible, so if an intruder doesn’t want to show up on the footage, he can easily disable the camera (there are many methods available).

Therefore, if you suspect that someone regularly (without your permission) enters your property, you may want to consider setting up a motion-activated nanny cam. This can work great with a traditional security cam, but you can also use it as an alternative.

The major advantage of a nanny cam is that it’s much harder to detect than a standard security camera.

Using a hidden cam may be illegal in some countries, so make sure you read the local regulations before installing.

Now let’s see what you can do if you want to be proactive.

10. Set Up Door Traps

There are many ways you can make sure that someone opened your door while you were out. You can mark the doorknob or the door handle, use transparent adhesive tape or a matchstick to detect if a door was opened.

I’ve written a whole article about the methods that work best if you want to detect if someone has opened your door. So I won’t repeat them here but you can find them all in this post.

11. Take Photos of Your Home

Unless you have an extraordinary memory, I highly suggest that you take photos of the items in your home.

This way you can easily compare their actual and original position. If they don’t match, then you’ll know that someone has been in your house and messed with them.

It’s not necessary, however, to take photos of each and every object. Take wide-angle photos and focus on those items that you think an intruder would move from its place.

You can find some examples above in the 5th section.

As an alternative, you can also record videos.

12. Use a Mat On Which the Footprints Remain

This is a somewhat sophisticated method and also one of my favorites.

The main idea behind this technique is that you place a mat in front of your door (on the inside) that’s made of longer fibers therefore it lets you see the imprint of someone’s shoes who has stepped on it.

This mark is usually clearly visible to those who know what to look for. If it sounds a little bit confusing, here’s a photo of what I’m talking about:

A footprint on a rugPin

It’s crucial that you take a photo of the mat before you leave the house, otherwise, it may be difficult to find out whether someone has stepped on it or not.

The larger the mat, the higher the chance the intruder will step on it.

Chances are good that you’ll find a mat in your house that is fit for purpose (most bath mats usually work great).

Pro Tip: If you have a not too heavy rug on a relatively smooth surface, you can form several small balls of reusable adhesive (mounting putty), such as Blu Tack, and carefully place them under the rug (scattering them around). When someone steps on the rug, some of the balls will lose their original shape and become flat.

13. Install Wi-Fi Motion Sensor

A standalone Wi-Fi motion sensor is pretty affordable nowadays, so if you’re seriously worried about someone entering your home while you’re away, you should consider installing a few of these gadgets.

The main advantage of a motion sensor is that it can put an end to speculation as it will immediately send an alert to your phone once it detects motion.

So it will tell you if someone is actually in your house or apartment.

The drawback is that if you have a pet (especially a larger one), that may lead to false alarms. However, if you also have a Wi-Fi enabled security camera installed that can easily clarify the situation.

If you’re not on a tight budget and want to take security to the next level, consider installing a reliable security system.

14. Scatter Tiny Pieces of Paper

How can a few pieces of paper help you tell if someone has been in your home?

Right before you leave your home, scatter a few tiny pieces of paper in front of your door. Then take a photo, leave the house and close the door very carefully.

When you get home and open the door you need to be extremely careful to prevent the airflow generated by the door from displacing the pieces of paper.

Take another photo and compare it with the previous one. If the two images are different, then chances are good that someone has opened the door.

If you live in a house, you may want to use cardboard instead of paper, especially if the weather is windy. In an apartment, both paper and cardboard can be a reasonable choice.

It’s a simple and free method, and when implemented the right way it can be powerful (especially when combined with other methods).

15. Install a Door Sensor

Similar to a motion sensor, a Wi-Fi door sensor will tell you in real-time whether someone has entered your home.

In fact, it monitors the status of your door and when someone opens it, the sensor immediately sends you an alert to your phone.

If you live with a pet, it may be a better option than a motion sensor. However, you need to buy multiple devices if you want to monitor your windows as well.

Putting It All Together

As you can see there are several ways to know if someone has invaded your privacy.

If you want to tell in hindsight whether someone has been in your house or apartment, you must actively look for the signs and traces (I’m not talking about a burglary when the signs are usually obvious).

As a general rule of thumb, the more of the above techniques you use, the more reliable results you will get.

If you suspect that somebody regularly invades your privacy (your former husband or wife, neighbor, previous tenant, or real estate agent for example), you will get the best results if you prepare in advance.

If you’re on a budget, combine several free methods with each other to get the most out of them. You can also use some gadgets, such as door and window sensors, nanny cams, and motion sensors that will often deliver superior results when it comes to unlawful entries.

A home invasion is a serious thing, and if you suspect that criminals have entered your property, do not hesitate to call the police.

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About the Author

James Mora is the founder of DailyHomeSafety. He is a home improvement expert, contractor, avid DIYer, and security manager. He is passionate about home repairs, remodeling, and teaching. Read More