Recently there has been some concern regarding the use of bump keys for criminal activity.

Bump Keys 

A bump key can be any key that fits a particular pin tumbler lock and that has been modified so that all of its cuts (or grooves) are made to the deepest allowable position as defined by each manufacturer.  The term "fit" means that the key will enter the keyway (the front of the lock) but will not unlock it.  For example, assume all of the locks in a particular apartment complex are produced by the same manufacturer and have the same keyway.  The key for apartment 101 can enter the lock of apartment 207 (or any other apartment) but will only unlock the apartment for which it was cut.  Any key cut for any apartment in this example could be modified to act as a bump key and then could be used to open any other apartment within the complex (or potentially any other complexes where the same manufacturer’s locks were installed). 

The term “bump” refers to the process of forcing the key to interact with the pin tumblers by bumping or rapping it with a plastic mallet while it is inserted into the lock.  This process entails hitting the head of the key, causing it to rapidly move forward.  When struck correctly, each of the bottom pins is “bumped” upward for a brief instant, thus allowing the lock to be opened. 

Despite the apparent effectiveness of key bumping, whether criminals are making widespread use of the technique to burglarize homes is questionable.  Higher security-grade locks are less vulnerable and non-pin tumbler locks (e.g. rotating disk locks, electronic locks, magnetic locks) are not vulnerable at all. 

Key bumping can involve a good deal of noisy banging so it isn’t necessarily an optimal method for covertly entering an occupied residence or one where adjacent residents might be within earshot. 

Again, please call the Police to report any suspicious activity and remember to be good neighbors and watch out for one another.

Emergency – Call 911
Non-Emergency – Call 301-279-8000