You may or may not have heard of the term "loiding" a door but you've probably heard of slipping a lock or seen someone slide their credit card through a locked door in a movie. Well, this article is about why and how that attack works.

Anatomy of a Deadlatch Plunger Door Handle

A typical door handle consists of a handle, spindle, strike plate, and plunger. Newer and especially high-security or exterior doors also have an additional piece called a deadlatch.

The deadlatch is a security mechanism to help prevent someone from quickly "slipping" a door by wriggling something between the plunger and the strike plate. The deadlatch presses against the strike plate when the plunger is inserted into the strike plate. As long as the deadlatch stays depressed against the strike plate the plunger cannot be fully depressed, thus the door cannot be opened. With the proper knowledge and know-how, an adversary can depress the deadlatch to allow the plunger to be depressed fully and the door is opened. This is why proper door fitment is so important to the physical security of your home and work facilities.

How to "Loid" a Door

Before moving on, you are probably saying, "Why do you keep referring to this as loiding a door?" In criminal slang slipping a door plunger to open it is referred to as loiding because a thin piece of celluloid or other plastic is often used. With that said, find yourself a sturdy piece of plastic trash. My favorite is a piece of broken plastic from a DVD or video game case. The plastic piece needs to be long enough to reach through the door, flexible enough to allow itself to be pushed through the door angles, and strong enough not to break/tear during the attack.

• First, slide the piece of plastic through the door from the top or bottom, I prefer going bottom up when the angle of the plunger is towards me and top-down when the angle of the plunger is away from me.
• Second, get the plastic pressed up against the plunger and work it into the plunger until you feel confident that the plastic is now between the plunger and the strike plate meaning that with the exception of the deadlatch, the door is ready to be opened.
• Third, if the fitment of the door is poor (and most are) then you can now pull the door towards you to slide the deadlatch into the strike plate's hole which will depress the deadlatch and allow the plunger to be fully depressed thus opening the door.

Quick video demonstration.