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Friday, November 13, 2009

A Word to the Wise T.I. - Stop Break Ins

Some of the way perps enter your home are:

1) Boost a child up to small first or second floor window, who then enters the home and either commits the vandalism or and lets the adults enter to do so.

2) Send a child in through a home's doggie door opening, who then enters and either commits vandalism or opens door so adults enter to do so.

3) Adult is, or pretends to be, in law enforcement and gets landlord to let him in.

4) Participating locksmith makes duplicate of your new key (because its code is in his key copying machine) and gives it to those who enter your home.

5) Adult convinces your child to open the door.

6) Adult uses the Bump Key technique. According to Wikipedia,

A typical bump key:

Lock bumping is a lock picking technique for opening a pin tumbler lock using a specially-crafted bump key. One bump key will work for all locks of the same type.


When the correct key is inserted, the gaps between the key pins (red) and driver pins (blue) align with the edge of the plug, called the shear line (yellow).

A pin tumbler lock is composed of a series of spring-loaded stacks called pin stacks. Each pin stack is composed of two pins that are stacked on top of each other: the key pin, which touches the key when it is inserted, and the driver pin, which is spring driven. When the proper key is inserted into the lock, all of the key pins and driver pins align along the "shear line," allowing the cylinder to turn. When the different length key pins are aligned at their tops by the insertion of the correspondingly cut key at their bases, the tops of the key pins and, consequently, the bases of the driver pins, form a straight line, so that the cylinder can be turned, rotating the key pins away from the driver pins. When no key or the wrong key is in the lock, pin misalignment prevents the cylinder from turning.

When bumping a lock, the key is initially inserted into the keyway one notch (pin) short of full insertion. Bumping the key inward forces it deeper into the keyway. The specially designed teeth of the bump key transmit a slight impact force to all of the bottom pins in the lock. The key pins transmit this force to the driver pins; the key pins stay in place.[9] This physics action can be visualized by observing the same effect on the desktop toy: Newton's Cradle. Because the pin movements are highly elastic, the driver pins "jump" from the key pins for a fraction of a second, moving higher than the cylinder (shear line of the tumbler), then are pushed normally back by the spring to sit against the key pins once again. Even though this separation only lasts a split second, if a light rotational force is continuously applied to the key during the slight impact, the cylinder will turn during the short separation time of the key and driver pins, and the lock can be opened while the driver pins are elevated above the keyway. Lock bumping takes only an instant to open the lock. The lock is not damaged in any way. Certain clicking and vibrating tools designed for bumping can also be used. These allow for rapid repetition of bumping against locks that have advertised "bump proof" features. Only a rare few key-pin locks cannot be bumped. Electronic locks that have a key backup are obviously completely susceptible to this method.

A different tool with a similar principle of operation is a pick gun.

1) Bump Resistant Lock: don't let locksmith open its packaging or take key(s) out of your sight for one second.

High-quality locks may be more vulnerable to bumping unless they employ specific countermeasures. More precise manufacturing tolerances within the cylinder make bumping easier because the mechanical tolerances of the lock are smaller, which means there is less loss of force in other directions and mostly pins move more freely and smoothly. Locks made of hardened steel are more vulnerable because they are less prone to damage during the bumping process that might cause a cheaper lock to jam.

Locks having security pins (spool or mushroom pins, etc.)—even when combined with a regular tumbler mechanism—generally make bumping somewhat more difficult but not impossible. Electronic locks, magnetic locks, and locks using rotating disks are not vulnerable to this attack.

Because a bump key must have the same blank profile as the lock it is made to open, restricted or registered key profiles are not any safer from bumping. While the correct key blanks cannot be obtained legally without permission or registration with relevant locksmith associations, regular keys can be filed down to act as bumpkeys.

Locks that have trap pins that engage when a pin does not support them will jam a lock's cylinder. Another countermeasure is shallow drilling, in which one or more of the pin stacks is drilled slightly shallower than the others. If an attempt were made on a lock that has shallow drilled pin stacks, the bump key will be unable to bump the shallow drilled pins because they are too high for the bump key to engage.

Many bump-resistant locks are available which can not be easily opened through the lock bumping method.
2) Provide some kind of physical barrier at each door.
* When at home, one T.I. got two two Closed Bar Holders, attached one to each side of the door frame, and passes a 2-inch by 4-inch hardwood board through the closed bar holders to secure her door at night. (see the above picture). Remember to drill 2-inch or 3-inch screws.

* Another T.I. purchased and installed on the top and sides of her door, 6 Hinge Locks (see picture below).

3) Get rid of, or block, doggie door.

4) Nail shut windows. or buy good locks that cannot be shaken or vibrated loose/open.

5) If possible have a responsible adult family member stay at home while you go out to shop or work.

6) Make sure that your sliding glass door can't be rocked off of its door glide from the outside.

Thanks to Aunt Bee, Shan, Julianne and other T.I.s for sharing their ideas on mulstistalk forum. Here's hoping that a A Word to the Wise T.I. is sufficient.