Chapter 15
Toolmarks
Class characteristics: type, size, shape
Individual characteristics: features from wear and damage
Photographed/sketched Taken to lab
if cant be taken to lab – tool mark is saved by casting Casting – silicone, plaster or clay
Lab Activity: Matching Toolmarks
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Photography and casting are important to match tool with mark.
Most people carry 5 -10 keys The most familiar lock – standard dead bolt
lock
Locks
Art Poholke in 1976
Identifies ◦ Method of entry ◦ Tools used ◦ Skill level ◦ Relative security of
system ◦ Additional evidence
Assists with ◦ Criminal investigations◦ Insurance claims ◦ Security maintenance
Forensic Locksmithing
Attempts to open the lock without producing a working key or decoding the correct position of components
Two tools ◦ Tension tool – gently apply
tension to the lock◦ Pick – position components
Correct position determined by touch, sound or sight
Lockpicking
These tools leave marks (gouges and scratches)
Fundamental weakness – every safe must be accessible to a locksmith in the event of a malfunction or lock-out
Two categories ◦ Fire safe - ◦ Burglary safe – not fire retardant
Most popular method of safecracking?
Safes
Two types◦ 1,2 or 3 number
combinations ◦ Up to 6 number
combinations
Parts of a lock ◦ Wheel pack◦ Combination dial attached
to the spindle◦ The spindle runs through
wheels and drive cam # of wheels = # of numbers
in combo
Combination Locks
Day locks Tryout combinations
◦ Standard and well known Lock manipulation –
using sound ◦ Determine contact points
– # clicks = # wheels◦ Discover # of wheels◦ Graph results – give you
the numbers but not the order
Methods to crack safes
Drilling Torching – burning a hole Exploding High-tech for electronic
locks
More methods
Serial Numbers
Restoration of serial numbers
Items of value may have ID numbers stamped into them.
Grinding is usually used to obliterate identification numbers.
To restore ID numbers on metal, an acid etching solution is used
polish with cloth
Clean with cuprous chloride solution
HCl-CuCl2