Ageing bloodstains

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Reflectance spectroscopy for recognition

and age determination of bloodstains

Rolf Bremmer and Maurice Aalders

Academic Medical Center

University of Amsterdam

The Netherlands

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This presentation was delivered by

Rolf Bremmer at the annual conference of the

American Academy of Forensic Sciences

in Chicago on February 25 2011

Prelimairy note

http://www.aafs.org/

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Aim of this talk

Presentation was nominated for Emerging

Forensic Scientist Award

Statement:

I have no financial or

commercial interest

I. Principles of reflectance spectroscopy

II. Bloodstain age determination

III. Discrimination between blood & non-blood

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Can we determine bloodstains at crime scenes

Paint-can, found next to a body at a crime scene

?

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RNA degradation

Bauer et al 2003

ESR

Fujita et al 2005

AFM

Strasser et al 2007

All: confirm changing chemical and physical properties

None: shown precision required for forensic application

Literature on age determination of bloodstains

http://www.ncbi.nlm.nih.gov/pubmed/14642725










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I. Principles of reflectance spectroscopy

Reflectance Spectroscopy - Bloodstain Age – Bloodstain recognition

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Reflectance spectroscopy

• Characterizes color

• Determines hemoglobin in bloodstain

• Non-destructive & results within a second

• Portable and applicable at crime scenes


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Reflectance spectroscopy schematic

1. Light source

2. Fibers

3. Spectrometer

4. Notebook


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Reflectance spectroscopy at the crime scene


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Reflectance spectrum of bloodstain


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II. Bloodstain age determination


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Hemoglobin in vivo


in vivo only 1% of hemoglobin is met-Hb

autoxidation

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Hemoglobin in bloodstains


denaturation

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Spectra of hemoglobin

HbO2 met-Hb Hemichrome


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Determine hemoglobin fraction in bloodstain


Hemoglobin spectra matched with non-linear least

squares fit to determine fractions of hemoglobin

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Four typical bloodstain reflectance with fit

HbO2 met-Hb HC

1 hour 0.89 0.01 0.10

1 day 0.60 0.05 0.35

7 days 0.35 0.16 0.49

56 days 0.16 0.17 0.66

Table: Fractions of Hb derivatives

based on fits

• • • • bloodstain reflectance

hemoglobin fit


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Hemoglobin in bloodstainsF

raction

(-)

Age (days)

HC

met-Hb

HbO2

Error bars represent

standard deviation

for n = 20.


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+

+

+

-----------------

Age ≈ 9 days

HC=0.53

HbO2=0.32

Met-Hb=0.18

Age determination of bloodstainsF

raction

(-)

Age (days)


met-Hb

HbO2

Measured fractions are matched

with typical kinetics to determine age

HC

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Inaccuracy increases with age

Typical Inaccuracy

9 ± 4 days

Disclaimer: Based on white cotton in a laboratory


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III. Discrimination between

blood and non-blood


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Is it blood?

ketchup

low fit quality

bloodstain

high fit quality


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A lot of red stains

Measured 40 bloodstains and 35 non-bloodstains

Specificity 100% and sensitivity 98%


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stain on paint-can is not blood(absence of blood was confirmed by tetrabase test)

Case report


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Summary

• Reflectance spectroscopy: cheap, non-destructive,

applicable at the crime scene

• Measure fractions of hemoglobin

• Determine age of bloodstain

• Discriminate between blood and non-blood

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Future research

• Determine influence of environment on ageing

• Extend measurements to dark colored

substrates

• Integrate spectroscopic measurement into

camera system

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Publications

• Age estimation of bloodstains by reflectance spectroscopy

Bremmer et al.

Forensic Science International 2011

• Non contact spectroscopic determination of blood volume fractions

Bremmer et al.

Biomedical Optics Express 2011

• Remote spectroscopic identification of bloodstains

Bremmer et al.

Journal of Forensic Science, in print

• Forensic Quest of Age Determination of Bloodstains, a Review

Bremmer et al.

Submitted to Forensic Science International

http://bit.ly/bloodstain

http://www.opticsinfobase.org/abstract.cfm?uri=boe-2-2-396

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Acknowledgements

Annemarie Nadort, MSc

Gerda Edelman, MSc

Martin van Gemert, PhD

Ton van Leeuwen, PhD

Nick Laan MSc

Karla de Bruin PhD

Ted Bijvoets

Rolf Bremmer, MSc

[email protected]

Find me on

mailto:[email protected]

http://www.linkedin.com/in/rolfbremmer

Technology

Ageing bloodstains