Through-the-Lock Entry for Storefront Doors

Article, photos, and video by Chad Cox

In forcible entry, there are a number of myths surrounding the through-the-lock method, specifically in regard to commercial-style doors, sometimes called aluminum-style doors (Photo 1).

The through-the-lock forcible entry technique originally developed in the 1960s in response to Americans becoming more security-conscious. People were installing more and better quality locks on their doors, making conventional forcible-entry techniques more difficult to perform. Firefighters discovered that that it was sometimes faster and much less labor intensive to go literally “through the lock” instead of conventionally forcing the door.

Through-the-lock basically duplicates the key action within the lock. The two-step process involves removing the lock cylinder and then actuatinng the lock mechanism. The firefighter can remove the cylinder by spinning it off using locking or water pump pliers, a K tool or other lock-pulling tool, or the adz end of halligan.

The mortise lock can be benchmarked with the location of the keyway. Consider the keyway in terms of a clock; generally, the lock is actuated from the 5 o’clock to 7 o’clock position or the 7 o’clock to 5 o’clock position (Photo 2).

(1) Standard storefront door.
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(2) Mortise lock exposed.
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Once the cylinder is removed, you now must actuate the lock using a key tool or Kerry tool (Photo 3).

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(4) Closeup of storefront door.
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Take the Glass?

With all forcible entry options on the table, time and time again, we hear people say, “Well, I would just take the glass.” Although taking the glass may very well get you into the structure, in doing so, you have violated a very crucial rule of forcible entry–maintaining the integrity of the door. Numerous articles stress the importance of controlling the door with regard to improper ventilation and so forth.

So you have decided to take the glass. Let’s say we were lucky enough that the glass was tempered or plate glass, now we have a floor full of glass shards over which we are going to be pushing the hose and crawling on our hands and knees. In our districts, we are seeing a trend with using laminated glass and even lexan to improve security for the business (Photos 5 and 6).

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Again, we hear the argument that it is cheaper to replace the glass than it is to have the locksmith replace the set screws in the cylinder. I challenge you is to go out and talk to your local locksmiths, and see what they have to say on the price differences.

Look at Photos 7-10 below. Once you have taken the glass (if you are able) on these doors, now what? Remember, you are at the scene of a fire. The glass is now gone, so the smoke and fire are now meeting you at the ventilation opening you just created. Would you grab the rotary saw and start sawing the bars away? Sure, you could do that, but again this is more time-consuming than just going through the lock, and we all know that time is quickly running out on us at the scene of a fire. We need to work smarter, not harder; we may now have to push the line in after forcing the door, conduct a search, and so forth.

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The following video demonstrates the difference in time between going through the lock and taking the glass (compare the time spent to the video of going through the lock above).

There are a million of ways to skin a cat, and there may be rare instances in which taking the glass is the only option. The through-the-lock technique is becoming a lost art, and as professionals, we must seek training to improve ourselves and educate our fellow firefighters.

The author thanks the following Witchita (KS) Fire Department personnel for their help in preparing this article: Captain Carlos Rodriguez, Firefighter Mark Misek, and the boys from Firehouse 10.


Wichita Heat (fire department newsletter)

FOOLS OF OZ Web site: (

Chad Cox is a veteran of the Wichita (KS) Fire Department. He is assigned to firehouse 1 and a member of the department’s hazmat response team. He is active in training and the vice president of the local FOOLS OF OZ Chapter. He can be contacted at

Subjects: Forcible entry, truck company operations, firefighter training videos

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