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Special Agent Technique: How To Escape From Handcuffs Using A Ruler by Derek Smith

As an agent I used handcuffs on bad guys quite often. It was one of my most essential tools of the trade. However, there was always a possibility that my handcuffs could be used against me or the bad guy may have handcuffs of his own, especially when I was undercover. Because of this I had to learn how to get out of handcuffs as well as I knew how to put them on a person.

Before I tell you how to escape cuffs I want to make this little disclaimer:

We DO NOT suggest you do this if slapped into cuffs by police. I warn you that you must not attempt this against law enforcement officers or they will either shoot you or beat you with their batons. This is for use only if you find yourself needing to escape an emergency situation, such as a terrorist attack or kidnapping. With that said, hopefully you’ll never have to experience being held in handcuffs someplace against your will, but if you find that you are, you will be glad I shared this little trick with you.

Before I show you how to get out cuffs, let me share a little information with you. In my work, I have seen all types of devices people used for getting out of cuffs, from hidden keys to improvised tools. I have also found these devices hidden in just about every crevice on a person’s body that you can think of. Here are a few of them:

Sim Rings

Shoe Lace Keys

Pen like devices

And many others!

One of several techniques I learned was to use the metal edge of a wooden ruler. Although I am teaching the use of a ruler, you can apply this technique to any piece of metal that you can use as a “shim” type device.

Standard-issue police handcuffs, or even hinged cuffs, can be rendered useless in a matter of seconds if you know what you’re doing. Read on to learn how to escape standard and hinged type cuffs.

Shimming works by inserting a thin piece of metal in above the ratchet, closing the ratchet a few clicks tighter, enough to slide the shim under the pawl. At this point, the ratcheted cuff swings free. I illustrate this below.


  1. Find a wooden ruler with a metal edge like in the photo. Remove the metal edge from the ruler. This bit of metal will be our “shim.”
  2. Insert the metal “shim” between the locking mechanism and the teeth. Slide it up into the locking mechanism so that it runs along the teeth; you’re essentially sticking it into the cuff along the rim.
  3. With the shim in place, tighten the cuff just one notch.
  4. Push the shim as you’re tightening the cuff, push the shim. The cuff should unclick.

Now, I leave you with a secret that other people don’t tell you. Handcuffs typically include a double lock feature which prevents the cuff from tightening once engaged. Shimming doesn’t work on cuffs that have been double locked.

Double locking a pair of handcuffs prevents the locking mechanism from moving in either direction, therefore stopping the locking arm from moving and making the closed cuff tighter. Therefore, a shim of any type will not work if someone has double locked the cuffs.

Below is a picture of my standard issued cuffs.

A standard handcuff key has a short barrel with a single tooth at the end for unlocking the cuffs. However, at the opposite end of the key you’ll find a short, blunt spike. Below is my standard issue key that accompanied the cuffs above.

On each cuff is a small slot in the locking mechanism housing. The slot is usually on the side of the cuff, perpendicular to the side where the keyhole is (see red arrow in picture below.)

If you’ve ever watched “Cops” on TV, you’ve probably noticed that when they slap the cuffs on a bad guy, they get out their key and seem to mess with each cuff. What they are doing is double locking the cuffs so they don’t get any tighter when the suspect sits in the car, and leans into the cuffs behind his back. We used to do this to prevent lawsuits should the bad guy say we somehow caused nerve damage to his wrists from the cuffs closing too tight on him.

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45 thoughts on “Special Agent Technique: How To Escape From Handcuffs Using A Ruler by Derek Smith”

  1. Another awesome pice of knowledge. This day and age the possibility of being in a hostage situation is there. And every tool you can add to your bag of tricks , be it mental,fiscal or miteral, to aid you an possibly your family’s chances of surviving a bad situation is most important..wish you would have been more complete in by showing how to get passed 2nd lock

  2. Wow this is soo interesting! I really enjoyed trying this out and, when it worked I was well chuffed. Thank you so much for showing this as it’s good to know. Jenna. U.K.

  3. Good evening,
    I retired from the Missouri Dept of Corrections..we always double locked the cuffs behind the guys.
    But one of the old inmates taught me how to pick them with a paper clip…doesn’the take long most of the time, sometimes old worn locks were harder..

  4. agree. that’s why always !! double lock !! and always use a black box on your cuff,s and if possible use non USA type cuff.

  5. YouTube can show how to shim. The technique is older than me but obsolete with new double lock cuffs. What about how to pick the new cuffs?

  6. Dear Derek Smith,
    Very interesting article by yourself on how to escape from handcuffs as I am a member of the Inner Magic Circle Gold Star in London. I specialised as an illusionist and escapologist escaping from any handcuff challenge, as well as straitjackets hanging from under helicopters and any number of different articles. I always collected the handcuffs if I succeeded and never failed to collect. If you like you can look up my name on the Internet.
    . TIMOTHY DILL-RUSSELL Age has unfortunately caught up with me so I am now semi-retired.
    All best wishes. Tim

  7. Blackie Hassenzella you definitely should do a GREAT frisk. I have found all kinds of stuff secreted on bad guys, even after someone else did an initial, inadequate frisk.

  8. Good info 2nd John. Also, see the comment I left for Fran Snow on the double lock. I really like the bobby pin recommendation too. Easy to carry and conceal. Thing is, if you find yourself in this situation you should know several methods because you don’t know which tools you will have access to.

  9. R. Albers there are many YouTube videos that you can watch for many different methods. Check out some of those. I should have done a video, damn!

  10. Rooster, the bobby pin is a good method too. There are many out there. One thing I want to correct though, that is my hand in the photos and I went to Staples, bought the ruler for about a buck and had my 10 year old shoot the photos while I shimmed the cuffs. However, you are correct, you don’t see them laying around much anymore.

  11. Hi Frank Snow, If you are using a bobby pin, which you can, insert the end of the bobby pin into the keyhole, and at the very edge, you want to bend the bobby pin down. this will release the ratchet, and open the jaws on the handcuffs. Now if they’ve been double-locked, insert the bobby pin in the keyhole on the other side. Release the double-lock. And then turn the bobby pin around, and re-insert it to release the ratchet and open the jaw.

    You may not get it the first couple of tries. But with a little practice, you should be able to slip out of handcuffs in under 10 seconds —

  12. Frank Mitchell, sorry to hear this happen and glad you worked it out. You said you could have used this year ago. Hopefully, you are not implying using against the police. I don’t want to get any of you hurt so don’t!

  13. Hi George, you can practice the same as I did. Get someone to put the cuffs on you and let you out of them if you cannot successfully free yourself. I have even had my kids do it for me.

  14. This tip could have been useful several years back. I was a Home-Watch Coordinator, and the local Bad Guys had started to threaten me. But they were perturbed by my interest in Fitness and Martial Arts. So some antisocial character told the Police I’d been downloading Child Porn, and I got arrested “On Suspicion Of Possessing Indecent Images Of Chldren”. I actually ended up defending myself in Chester Crown Court. Which wasn’t as risky as you might think: The supposed Evidence was so ridiculous that the Prosecution had to drop the case.

  15. Very informative. I was not aware of the double lock feature. This is good to know. Thank you for sharing this information with us.

  16. Interesting information and good to know but I noticed there was no follow up about getting out of,or not getting out of,double locked cuffs.

  17. I have found THIS particular hack to be obsolete. Take a survey trip to the local dollar store. You will find that the majority of the rulers are plastic! THIS renders the hack 100% useless. MY resolution for this situation is wearing a “bobby pin” astride my belt out of sight under the belt loop to the dominant hand side. (IF you are searched, they will most likely check the center belt loop and ignore the rest). The pin can be opened to use in either the shimming method described for the wooden ruler or it can be formed into a sweeping tool.

  18. Great for cheap cuffs without a double lock.. Info would have been usefull if it showed how t defeat the double lock also

  19. I truly appreciate your help in so many different situations.
    You are wonderful to me and so many others.
    🌷
    Thank you from the bottom of my heart
    Suzi Zimmerman*

  20. Very interesting to know, it would also be nice to know what can be used to open cufflinks that you may have on yourself.

  21. As a retired “hack, turn key, etc.” or known as a CO, or Correctional officer the end of old style pen replacements can be nicked at the other end and ford over the the locking device and turned as a key. Old government pens with the metal cartridge was the best. Also a tooth brush carved correctly will do the job.

  22. Good information. Two more reasons to check the restraints on the bad guy. 1. To check he is still secure and 2. to ensure you doublelocked the restraint. Also check the perps for shim stock.

  23. I still have my leather, cuffs, Python and carry a cuff key but I guess I’m breaking the law huh? 410ken cop in the sixties. ps a bobby pin works too.

  24. I share this technique with you to prepare you if you are kidnapped or held by terrorist or anyone except the police. Please don’t try this against law enforcement.