The document discusses various methods used in criminal investigations including tool mark analysis, lock picking, safe cracking, and restoring serial numbers. Tool marks and casts are used to match tools to crime scenes. Lock picking involves using tension and pick tools to open locks without keys. Safecracking methods include drilling, torching, or manipulating combination locks. Serial numbers can be restored using an acid etching solution.

2. Class characteristics: type, size, shape
Individual characteristics: features from wear and damage

3.  Photographed/sketched
 Taken to lab
 if cant be taken to lab – tool mark is saved by casting
 Casting – silicone, plaster or clay

5. Photography and casting are important to match tool with mark.
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6.  Most people carry 5 -10 keys
 The most familiar lock – standard dead bolt
lock

7.  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

8.  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

10.  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?

11.  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

12.  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

13.  Drilling
 Torching – burning a hole
 Exploding
 High-tech for electronic
locks

14. 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