can result in allegations of evidence spoliation. Such allegations can put you and your findings at risk. Key Insertions During conference polling of forensic locksmiths and as discussed above (in- dependent, unpublished testing), classi- fying key insertion as a destructive test was overwhelmingly dismissed when done under the proper conditions. There is also a logic associated with this position based on the design of the lock, intended life ex- pectancy and nature of the materials from which the tumblers and keys are made. The construction materials keyway and design of the cylinder determine how the individual parts wear. Wear is the di- rect result of contact, pressure and move- ment. Wear in locks occurs when the key contacts the spring-loaded tumblers and forces them out of its way and into a po- sition associated with the cut depth on the key. In automobiles, additional wear develops because of the movement of the key within the lock while the vehicle is in operation. The wear is exacerbated by the additional weight placed on the key by other dangling keys, key chains and other items oſten linked to a key ring. However, most vehicles never require re- placement of the ignition lock or key due to wear during its entire service life. This is because the ignition and door locks to an automobile are designed to last the life of the vehicle. Typically, the automotive industry ac- cepts the life expectancy of a vehicle to exceed 100K miles of operation. If a driv- er drives the average distance per year, now accepted to be 12K to 15K miles per year, one could suggest that the vehicle’s operational life expectancy is at least six to seven years. Although there are no published criteria on insertion ratios (the number of key insertions relative to vehi- cle mileage), it would be reasonable to as- WWW.ALOA.ORG “Accusing a forensic locksmith of evidence spoliation because a key was inserted in a lock is like accusing a medical examiner of spoliation because an incision was made during an autopsy.” sume that the average driver would insert the key into the ignition multiple times per day. Let’s say, for this example, four times per day. If the operator inserts a key in the ignition four times per day, 250 days per year, the ignition key is inserted in an ignition lock 6,000 to 7,000 times over the life of the vehicle. If, during this time, the lock components wear so little that they survive this span (and typically beyond), than it would be reasonable to say that from a wear perspective, one, two, three or even four insertions of the key (typical during testing) would have no identifiable effect on the contact sur- faces of the lock of key. Automotive System Bypass Indicators While on the subject of vehicle locks, ve- hicles are stolen by one of two methods: driving or towing. In most cases, the lat- ter does not require a key (although it does require a tow truck). With towing, little, if any, physical evidence directly attributable to the alleged thieves’ meth- od of vehicle removal may be recovered. However, it is generally accepted (and documented by interviews of captured car thieves) that a thief who is taking the greater risk (by using a tow truck) is expecting the greater reward (more money). Thus, the monetary gain real- ized by the thief is a great consideration when suggesting that the theſt is executed by tow vehicle. If the stolen vehicle was driven, the thief must have bypassed the anti-theſt/theſt deterrent systems or had a “working” key. Indicators of system bypass are oſten also revealed during post-recovery ex- amination. If the thief had a key, then that key was made from a code or us- ing a known key as a master. This “new” key will likely have a different shape or contour than the routinely used key and will oſten have burrs that may or may not have been removed following cut- ting. Assuming the “new” key is metal, the potential of marking the interior of the lock exists (albeit limited). However, due to difference in the character of the new key, any markings on the tumblers associated with that “new” key would be in a different location on the contact sur- faces. Such markings are generally iden- tifiable during otoscope/ophthalmoscope examination. If such markings are iden- tified during otoscope/ophthalmoscope examination, the technician would nor- mally elect not to insert the (provided) key unless other testing (that requires key insertion) is deemed essential. Regardless, post-recovery insertion of a supplied working key will not strike the tumblers in the same fashion (and loca- tion) as the “new” key; therefore, it will not alter or otherwise obliterate markings APRIL 2018 KEYNOTES 15
