ADMJ 1100 Lecture Notes - Lecture 6: Nuclear Dna, Gas Chromatography, Tablespoon
29 May 2018
School
Department
Course
Professor
CSI
Chapter 6 Lecture Slides
Trace Evidence
Trace evidence is very small physical evidence that requires microscopy, electronic instruments,
or a combination of the two to be examined in a lab
- Often overlooked at the crime scene but can be crucial to conviction
- It is extremely fragile and can be easily damaged or disappear if not collected
immediately
- i.e. hair, fibers, glass, soil, arson accelerants
Locard Exchange Principle
- Transfer evidence: transfer of trace amounts of material
- Primary transfer: transfer of evidence from one individual or object to another
individual or object
- Secondary transfer: transfer of trace evidence from the object it was transferred to in
its primary transfer to another (secondary) place or thing
Hair Evidence
- Most frequent found trace evidence found at a violent crime
- Can determine:
o Animal or human
o Individualization (sometimes)
o Excludes a suspect
o Race (sometimes)
o Oigi of the loatio of the soue’s ody
o Whether the hair was forcibly removed
o If it had been treated with chemicals (dyed, permed, or straightened)
o If drugs have been ingested
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- Race
o European hair: medium coarseness and are generally straight or wavy, blonde to
brown to black
o Asian, Native American, and Hispanic are regularly coarse, straight, and circular
in cross section
o African are regularly curly or kinky, have flattened cross section, and can appear
curly, wavy, or coiled
- Hair Removal
o Naturally shed hairs display undamaged, club-shaped roots
▪
o Forcibly removed from the scalp will exhibit stretching and damage to the root
area
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o Forcibly removed hair may have tissue attached
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find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Trace evidence is very small physical evidence that requires microscopy, electronic instruments, or a combination of the two to be examined in a lab. Often overlooked at the crime scene but can be crucial to conviction. It is extremely fragile and can be easily damaged or disappear if not collected immediately i. e. hair, fibers, glass, soil, arson accelerants. Transfer evidence: transfer of trace amounts of material. Primary transfer: transfer of evidence from one individual or object to another individual or object. Secondary transfer: transfer of trace evidence from the object it was transferred to in its primary transfer to another (secondary) place or thing. Most frequent found trace evidence found at a violent crime. Individualization (sometimes: excludes a suspect, race (sometimes, o(cid:396)igi(cid:374) of the lo(cid:272)atio(cid:374) of the sou(cid:396)(cid:272)e"s (cid:271)ody, whether the hair was forcibly removed. If it had been treated with chemicals (dyed, permed, or straightened)
