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