Successfull Misinterpretation of Evidence

Successfull Misinterpretation of Evidence

Kantonspolizei
Successfull
Misinterpretation of
Evidence
A "classical homicide"
01.10.2010 / Seite 1 / KAPO_Powerpoint_Vorlage.pot
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Our GSR analysis
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Application of the results
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Sentence
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Origin of the GSR
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Contamination occasions
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• While arresting a suspect by the hands of the
police officer
• While sampling a suspect by the hands of the
police officer
• While the samples are transferred to the lab
• While the samples stored on a shelf waiting to be
analyzed
• While putting the samples into the SEM
• While questioning in Policeoffice before sampling
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Sampling for our research
• in a police car
• in a prison van
• at the desks of our
offices
• chairs used during
questioning
• at our lab
• near the SEM
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Our results: GSR positive
using SEM/EDX we detected GSR:
• on our desks
• on the shelves used for storing the samples
• on the backseat of the car of a police officer
• on a stub that was left open for one week in our
shooting range
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Our results: GSR negative
using SEM/EDX we could
not find any GSR …
• in some police cars
• on the console table of
the SEM
• on the chairs in two
rooms used for
questioning of suspects
• in a prison van
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sample in SEM room, open for 2 weeks
office desk Forensic-Scientific Service
Number of PbBaSb particles
of the samples
captives seat in the captives transport car
chair in room for inquiries
chair in room for inquiries
chair in room for inquiries
chair in room for inquiries
operators desk SEM
police car, back seat
police car, back seat
police car, back seat
police car, back seat
drivers seat CSI-Team
office desk CSI-Team
blind
blind
captives seat in the captives transport car
shooting range, sample open during sampling
police car, back seat
police car, back seat
office desk Forensic-Scientific Service
sample storage shelf
drivers seat Forensic-Scientific Service
police car, back seat
police car, back seat
shooting range, horizontal surface
office desk Forensic-Scientific Service
shooting range, open during shooting
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0
20
40
60
80
100
120
140
Consequences for future GSR analysis
• We have to sensitise the police officers for
contamination issues.
• In our reports we can state only whether we have
found GSR or not.
• We may open the casings of the stubs carefully
and only for transfering the stubs into the SEM.
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Kantonspolizei
Thank you for your kind
attention
[email protected]
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