5 Common Signs Your Locks Have Been Tampered With and What to Do About It

Learn the warning signs of lock tampering so you can take action and keep your home safe

Family walking in front door
Photo: Monkey Business / Adobe Stock
Family walking in front door
Photo: Monkey Business / Adobe Stock
Highlights
  • Physical signs of lock tampering include damage around the door frame and scratches around the keyhole.

  • Upgrading your locks and installing a home security system can help prevent future break-ins.

  • If you suspect your locks have been tampered with, call 911 and hire a locksmith to boost security. 

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Have you ever arrived home, looked at your front door, and had the feeling something was wrong? When that feeling of fear or stress creeps up, don’t just shrug it off. Learn what to look for so you can take proper action if you think your locks have been tampered with while you were away.

1. Your Lock Doesn’t Function Properly

Even if you don’t immediately notice signs of tampering, if your key doesn’t turn as easily as usual, that’s a red flag. Once you notice that your lock isn’t functioning the way it normally does, look around for any visible warning signs of damage. In the best-case scenario, the malfunctioning lock is due to another reason, and you’re just taking precautions.

Angi Tip

If you're locked out of your home during an emergency with kids or pets stuck inside, call 911 for help.

2. Signs of Forced Entry 

If you see obvious signs of damage or unnatural wear, it’s likely that an attempted burglar tried to use sheer brute force to enter your home. If someone tried to drill through your deadbolt, bash in your lock, or simply kick down your door, you may notice one or more of the following:

  • Twisted or bent metal deadbolts or latches

  • Warped wood on doors or door frames

  • Splintered wood on the ground around the doorway

  • Paint circles near the lock fixture, as if it was loosened, moved, or retightened out of place

3. Tiny Scratch Marks Around the Keyhole

If you’ve ever seen a heist movie, you’re probably familiar with lock-picking. This traditional method of lock tampering is gentle and doesn’t leave much of a trace. Typically, a burglar uses a small pick or flat screwdriver to take the pin tumblers in your lock until they all catch and the lock turns.

As these small tools wiggle around inside your lock, they may cut into edges and leave marks. If you notice that your key is harder to turn than usual, check around the keyhole for tiny scratch marks or fresh, shiny metal marks finer than those left by your key. These are hard to notice but could be signs that someone tried to pick your lock.

4. New Nicks or Shiny Metal Edges Around the Keyhole

Similar to picking, burglars use a technique called bumping that can leave subtle signs or even no signs at all. Developed by locksmiths in the early 1900s, bumping involves the use of a standard key with teeth that have been filed down into saw-like points. This “dummy key” is fully inserted into a compatible lock and hammered carefully to catch all pin tumblers.

Like picking, this method, when done correctly, can leave no trace. If done too forcefully, however, bumping could leave fresh nicks and shiny metal edges around the keyhole that look like they’ve been recently hit.

5. Drilling Around the Lock

Sometimes, a burglar will choose the most straightforward unlocking method: removing the lock completely. Drilling around the lock will destabilize it, making it easy for someone to knock it out of the door with direct impact. Look for small, regular, circular holes around your lock. If you can see through the hole, it’s most likely a result of drilling.

You may also notice a new hole on the lock itself, often near or directly on top of the keyhole. That tells you someone was trying to destroy the lock tooth altogether by drilling into it. Both are alarming signs and should be addressed immediately.

What to Do If You Think Someone Has Tampered With Your Locks

Once you know what to look for, you can more confidently assess whether someone has attempted to break into your home. If you do suspect attempted burglary, there are several steps you can take to maximize your safety.

Take Notes and Gather Evidence

If you only see subtle signs and are unsure that a crime occurred, remain calm and continue to gather evidence. Take note of anything that is missing, moved, broken or deformed in or around your home.

Call 911

If there are enough obvious signs of damage or theft, be wary about entering your home in case entrance was gained and the intruder is still present. Immediately contact the police and file a report.

Contact a Professional Locksmith

An experienced residential locksmith in your area can visit your home to check out your lock. They will confirm whether it looks like it was tampered with or make repairs if needed. They can also offer advice on how to upgrade your locks for better security.

How to Prevent Lock Tampering and Break-Ins

Now that you know the telltale signs of lock tampering and how to respond when you see them, take some simple steps to prevent future burglary attempts and give you peace of mind. Even if you haven’t experienced the signs of lock tampering, being proactive will give you peace of mind.

Reinforce Your Doors and Windows

Look for vulnerabilities in your home’s entrances. Sliding glass doors or those made with flimsy wood are easy targets for would-be intruders. Ensure that your exterior doors are made from heavy wood or metal, and reinforce windows with looks, dowels or track fillers. Always securely shut, lock, and deadbolt exterior windows and doors when you leave your home.

Upgrade Your Locks

Especially if you’re only using the locks that came standard with your doors, consider replacing them with high-security locks that are pick-proof or bump-proof. There are digital lock options that rely less on traditional tumblers and pins.

Deadbolts are considered the safest type of lock, in part because they help reinforce the door against brute force entry and lock picking simultaneously. Deadbolts with long bolts of hardened steel that extend at least one inch inside your door frames are harder to pry or saw open. To maximize the performance of any new lock, have it installed by a professional locksmith. The cost to hire a locksmith to install a deadbolt is about $40 to $75

Maintain Existing Door Locks

Front door of house
Photo: dpproductions / iStock / Getty Images

Like any part of your home, locks age with time and wear. A dirty lock can become fragile and more likely to break. With just a few minutes of effort at least twice a year, you can clean and maintain your locks to prolong their useful life span. Simply use a lubricant specifically designed to flush dirt out of your locks.

Another tip is to keep track of who has keys to your home. If you forgot to collect the copy you gave to your former dog walker or house sitter, you may want to change your locks

Install a Home Security System

Installing alarms and security cameras can deter intruders before they reach your newly upgraded locks. Install cameras or video doorbells with live feeds that you can monitor from your smartphone, as well as alarms that go off during an attempted breach of your doors or windows.

Installing alarms and security cameras can deter intruders and prevent package thefts before they reach your newly upgraded locks.

You’ll find home security packages at a variety of price points depending on your needs and budget, but most tend to lead burglars to skip the homes they guard in favor of easier targets. Contact a local home security service for more information.

Frequently Asked Questions

Lock bumping is a technique locksmiths use to quickly and quietly open a pin tumbler lock, typically found in most types of deadbolts. It involves inserting a specially crafted key, or bump key, into the lock and tapping or "bumping" it with a mallet or similar tool. The force applied causes the lock's pins to jump momentarily, allowing the lock to be turned and opened. Unfortunately, thieves also use this technique to break into homes. Luckily, products like a deadbolt strap will fortify your lock.

Lock picking is a relatively subtle method of unauthorized access, making it hard to detect. But there are telltale signs to look for. First, look for scratches or tool marks around the keyhole or the lock's surface. Also, check for loose or misaligned components, like a wonky strike plate, which could indicate tampering. Consulting a locksmith or security professional for an assessment can provide valuable insights, too. Investing in high-quality locks and considering additional security measures, like security cameras, can help deter potential intruders and enhance your overall safety.

Regrettably, entirely pick-proof locks don't exist unless you opt for keyless varieties. Locks advertised as "pick-proof" are, in reality, more resilient against lock-picking and bumping attempts because of complex mechanisms consisting of pins and sidebars. These locks work like this—they assign two tasks to the key, enhancing security by making unauthorized entry more challenging.

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