Acid attacks on pin-tumbler locks.

Recently, an unusual method of home burglary has emerged in several European countries. Nitric acid is used to attack the tumbler lock of the front door. The aim of this study is to gain insights into the technical functioning of this method and to evaluate the advantages and disadvantages of this modus operandi. For this purpose, four pin-tumbler locks were attached to a custom-made holder and 65% nitric acid was successively injected into the key channel using a syringe. The locks were checked manually and using a CT scanner to see whether the lock was overcome and how the acid did affect the pins and springs. In three out of four cases the lock was overcome. The shortest time was 22 min until the pin pairs could be removed and it was possible to turn the core with a screwdriver. Overall, the results show that the modus operandi works with standard locks. According to the authors, the long duration and the high health risk are significant disadvantages in relation to other overcoming methods.