Evidence Types and Their Uses in Forensic Investigation
Trace Evidence
Relates to locard's principle of exchange: every conduct leaves a trace.
The transfer of small quantities of physical evidence that helps link a suspect to the scene/victim or vice
versa.
Eg: Hair, Fibres, Pollen, Glass, Gunshot residue.
How is trace evidence transferred?
“Every contact leaves a trace” – Locards principle
"Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent
witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes,
the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or
collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is
not confused by the excitement of the moment. It is not absent because human witnesses are. It is
factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent.
Only human failure to find it, study and understand it, can diminish its value."- Paul L Kirk
Why is trace evidence useful?
-Can link objects and people together.
-Where did it happen.
-Did they use transport? – to get there/get away?
-Also help victim and find suspect.
Trace evidence – The object
Trace on the hammer may include:
-Blood/Tissue from Victim
-Blood/Fingerprints from Suspect
-Fibers from Rug in van
, Trace evidence – The location
Trace evidence on the rug may include:
Blood/Tissue from Victim
Blood from Suspect
Trace evidence – The victim
Trace evidence on the victim may include:
Blood/Semen from Suspect
Fibres from Rug in van
Trace evidence – The suspect
Trace evidence on suspect may include:
Blood/Tissue from Victim
Fibres from Rug in van
Why is trace evidence useful?
Crime scene investigation is based on posing and answering the fundamental questions
The 6Ws
In themselves and through their interrelationships they provide the strongest FRAMEWORK for the
planning and conduct of investigation of a crime scene
The 6 Ws are not isolated but each is linked with the others.
Each question can produce information that impacts on one or more of the others.
Trace Evidence
Trace evidence is made when contact between two objects/persons occurs.
Trace evidence refers to small, often microscopic evidence.
Common types of trace evidence are:
Gunshot Residue
Hairs & fibres
Paint fragments
Glass fragments
Trace Evidence
Relates to locard's principle of exchange: every conduct leaves a trace.
The transfer of small quantities of physical evidence that helps link a suspect to the scene/victim or vice
versa.
Eg: Hair, Fibres, Pollen, Glass, Gunshot residue.
How is trace evidence transferred?
“Every contact leaves a trace” – Locards principle
"Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent
witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes,
the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or
collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is
not confused by the excitement of the moment. It is not absent because human witnesses are. It is
factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent.
Only human failure to find it, study and understand it, can diminish its value."- Paul L Kirk
Why is trace evidence useful?
-Can link objects and people together.
-Where did it happen.
-Did they use transport? – to get there/get away?
-Also help victim and find suspect.
Trace evidence – The object
Trace on the hammer may include:
-Blood/Tissue from Victim
-Blood/Fingerprints from Suspect
-Fibers from Rug in van
, Trace evidence – The location
Trace evidence on the rug may include:
Blood/Tissue from Victim
Blood from Suspect
Trace evidence – The victim
Trace evidence on the victim may include:
Blood/Semen from Suspect
Fibres from Rug in van
Trace evidence – The suspect
Trace evidence on suspect may include:
Blood/Tissue from Victim
Fibres from Rug in van
Why is trace evidence useful?
Crime scene investigation is based on posing and answering the fundamental questions
The 6Ws
In themselves and through their interrelationships they provide the strongest FRAMEWORK for the
planning and conduct of investigation of a crime scene
The 6 Ws are not isolated but each is linked with the others.
Each question can produce information that impacts on one or more of the others.
Trace Evidence
Trace evidence is made when contact between two objects/persons occurs.
Trace evidence refers to small, often microscopic evidence.
Common types of trace evidence are:
Gunshot Residue
Hairs & fibres
Paint fragments
Glass fragments
