Demystifying the Chain of Custody & Forensic Arson Analysis - IAAI 2017

© 2016
Chemistry Matters Inc.
Demystifying the Chain of Custody &
Forensic Arson Analysis
April 14, 2017
IAAI 2017, Las Vegas
Court Sandau, PhD

© 2017
Copyright Statement
2
All rights reserved. No part of this publication may be
reproduced, distributed, or transmitted in any form or by
any means, including photocopying, recording, or other
electronic or mechanical methods, without the prior written
permission of Chemistry Matters Inc.
IAAI 2017 – Demystifying COC & Forensic Arson Analysis

© 2017
Introduction and Course Outline
3IAAI 2017 – Demystifying COC & Forensic Arson Analysis

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Introduction
4
Court Sandau, PhD, PChem
-PhD in Analytical Chemistry (2001), BSc –
Chemistry/Env.Sci (1995)
-Worked 5 years at Environment Canada laboratory
during PhD
-Worked 4 years at Centers for Disease Control and
Prevention (CDC) in Atlanta (2000-2004)
-Returned to Canada in 2004 – Forensic Chemistry
Consultant and Expert Witness
- Testifying on sampling, analysis and interpretation
- Legal sampling and scientific method lectures to
regulators/industry
- Specialize in forensic cases (chemical, environmental,
geochemical)
- Have worked on arson cases since 2011

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Goal of Seminar

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Syllabus
6
• Analytical Chemistry of Ignitable Liquids Analysis
• What is legal sampling?
• Legal Chain of Custody
• Field Notes and Documentation
• Sample Containers
• Field Sampling
• Future of ILR Analysis
• Case Study

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Starts with the Chemistry –
Measurement Chemistry (Analytical)

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What are the limits in Analytical Chemistry?
8
What are the limits?
• How low can you go?

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How low can we go?
9
m/z 321.8936 [M+2]
Using cryo-focusing and HRMS, can achieve 540 ag 2378-TCDD, assuming 70
% recovery S/N 474 (4 Sigma)
m/z 319.8965 [M]
Dr. Jef Focant, Dr. Donald G. Patterson, Jr and Wayman Turner

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Extreme Sensitivity – 2,3,7,8-TCDD
10
Weight Moles Parts per Molecules
Microgram (10-6) 3 Nanomoles (10-9) ppm 2,000,000,000,000,000
Nanogram (10-9) 3 Picomoles (10-12) ppb 2,000,000,000,000
Picogram (10-12) 3 Femtomoles (10-15) ppt 2,000,000,000
Femtogram (10-15) 3 Attomoles (10-18) ppq 2,000,000
Attogram (10-18) 3 Zeptomoles (10-21) ppquint 2,000
Zeptogram (10-21) 3 Yaktomoles (10-24) ppsextillion (pps) 2
Yaktogram (10-24) 3 Fantomoles (10-27) ppseptillion (ppsep) 0.002
Currently at the attogram level with high resolution mass spectrometry

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Chemistry Matters Inc. 11Footer Here - Edit with the "Header and Footer" option at top
One part-per-quadrillion
(ppq or ag/µL)
is like measuring
1 second in 1 x 1015 seconds
… or 1 second in 32,000,000 years

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Chemistry Matters Inc. 12IAAI 2017 – Demystifying COC & Forensic Arson Analysis
Detection Limits for Ignitable Liquid
Residues
Weight Moles Parts per Molecules
Microgram (10-6) 3 Nanomoles (10-9) ppm 2,000,000,000,000,000
Nanogram (10-9) 3 Picomoles (10-12) ppb 2,000,000,000,000
Picogram (10-12) 3 Femtomoles (10-15) ppt 2,000,000,000
Femtogram (10-15) 3 Attomoles (10-18) ppq 2,000,000
Attogram (10-18) 3 Zeptomoles (10-21) ppquint 2,000
Zeptogram (10-21) 3 Yaktomoles (10-24) ppsextillion (pps) 2
Yaktogram (10-24) 3 Fantomoles (10-27) ppseptillion (ppsep) 0.002
Routine ILR analysis is at the ppb level with benchtop mass
spectrometry.

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Sample Extraction

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The Analytical Laboratory
There is no precise regulation for the determination
of accelerant in a sample. Methods provide general
guidelines and approaches to how to conduct the
analysis and identification.
Each laboratory will have its own lab process from
allowable ASTM methods AND identification
process.
If a laboratory is not used to dealing with arson
samples there could be issues with false positives
AND/OR false negatives.

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Sample Extraction
Two main analytical routines both use Passive Headspace
Concentration.
oASTM E1412 – …With Activated Charcoal.
oASTM E2154 – …With Solid Phase Microextraction (SPME).
Both use moderate heating to enhance
the evaporation of ILRs from the sample
onto a receiving matrix.
Activated charcoal method, the matrix is
extracted with a solvent, which is then
analyzed for the presence of chemicals
associated with ILRs.
SPME fiber is exposed to headspace
then directly injected onto GC-MS.

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Sample Extraction
Equipment:
• Can containing fire debris (sample from field)
• Carbon strip – activated and cleaned (heat treated)
• Pin – heat treated
• Magnet – strong lanthanide magnet

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Heating a sample
• Heating a sample transfers compounds from matrix to
headspace of can
• Carbon strip then adsorbs compounds
• Headspace important – cans should only be ¾ full
Interferences
Target compounds
Inc. flashpoint
Heat volatilizes
target
compounds into
headspace
Carbon strip
adsorbs
compounds
Heated Can

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Laboratory Analysis
18
Heat volatilizes
target
compounds into
headspace
Carbon strip
adsorbs
compounds
Heated Can

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Limited Seating Available
• Sometimes there is not enough space for target
molecules to bind to either the SPME or the
carbon strip due too many interferences.
– Could result in false negative.

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Analysis of Sample
Two Parts:
Gas Chromatography
Mass Spectrometry

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Gasoline Chromatogram
6 7 8 9 10 11 12 13 14
Time (min)
0
Figure 1 Summed mass chromatogram for weathered diesel, k
RT: 6.00 - 14.00
6 7 8 9 10 11 12 13 14
Time (min)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
RelativeAbundance
NL: 8.28E6
m/z=
90.50-91.50+
104.50-105.50+
118.50-119.50 + m/z=
105.50-106.50+
119.50-120.50+
133.50-134.50 MS
0801009
ethylbenzene
m,p-xylene
o-xylene
n-propylbenzene
3-ethyltoluene
4-ethyltoluene
1,3,5-trimethylbenzene
2-ethyltoluene
trimethylbenzene
C4-benzene
1,2,4,5-tetramethyl-benzene
1,2,3,5-tetramethylbenzene
Three
Musketeers
Castle
Group
Gang
of
Four
Interferences
Target compounds
Lower flashpoint
Sample in
Detector
Column
Target compounds
come out at same
retention time for
each analysis.

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Mass Spectrometry
Figure 1 Summed mass chromatogram for weathered diesel, kerosene and gasoline
RT: 6.00 - 14.00
6 7 8 9 10 11 12 13 14
Time (min)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
RelativeAbundance
NL: 8.28E6
m/z=
90.50-91.50+
104.50-105.50+
118.50-119.50 + m/z=
105.50-106.50+
119.50-120.50+
133.50-134.50 MS
0801009
ethylbenzene
m,p-xylene
o-xylene
n-propylbenzene
3-ethyltoluene
4-ethyltoluene
2-ethyltoluene
trimethylbenzene
C4-benzene
Three
Musketeers
Castle
Group
Gang
of
Four
Figure 2 Summed mass chromatogram for regular gasoline
Provides highly
specific identification
of each chemical.

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Chemical identification
• We know where each of our marker compounds
elute from GC
• Each compound has distinctive mass spectrometry
fingerprint which can be matched to library
78% match
Library
Sample

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Data Analysis

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Look for Distinctive Patterns
25
Three Musketeers
C2-benzenes
Castle Group
C3-benzenes
Gang of Four
C4-benzenes
Twin Towers
C1-naphthalenes
Five Fingers
C2-naphthalenes

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Ignitable Liquid Types

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Example profile - alkylbenzenes
Gasoline
Kerosene
Diesel

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Matrix Effects

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Burnt baseboardsChar debris
Burnt Flooring Control Flooring
Soil and humusForest debris
ILRs are readily extracted from all types of material.
Analysis patterns can be compared regardless of sample type.

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Gasoline - No Matrix
30
Three Musketeers Castle Group Gang of Four Twin Towers

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Gravel

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Burnt flooring

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Burnt wood and
glass

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Burnt carpet and
flooring

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Partly burnt flooring

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Fresh Vegetation
Pinene
Limonene
p-cymene
secbutyl benzene
Lots of natural chemicals, but can still see pattern of
gasoline

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How complicated can it get?
37
++
=
?

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How complicated can it be?
38
How many compounds are in….
• The atmospheric aerosol from a coniferous
forest?
• The volatile fraction of roasted coffee beans?
• Cigarette smoke?
• Gasoline?
• 50 compounds (Kallio, 2006)
• 1,000 compounds (Mondello, 2004)
• 6,000 compounds (van Mispelaar, 2005)
A. < 50 B. 50-100 C. 300-500 D. 500-1000

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Implications on Analysis
• For wildfires (especially), sampling natural areas
(bark, pine needles, forest ‘debris’, mossy soil
– Large concentration of natural compounds that are
structurally similar to target compounds
– Natural compounds present in % quantities
• All compounds (natural and ILR) are competing for
“limited seating” on SPME fiber or carbon strip.
– High potential for false negatives

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How complicated can it get?
40
++
=
Thousands of Compounds

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Overall Laboratory Output

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Chemical identification
Figure 1 Summed mass chromatogram for weathered diesel, kerosene and gasoline
RT: 6.00 - 14.00
6 7 8 9 10 11 12 13 14
Time (min)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
RelativeAbundance
NL: 8.28E6
m/z=
90.50-91.50+
104.50-105.50+
118.50-119.50 + m/z=
105.50-106.50+
119.50-120.50+
133.50-134.50 MS
0801009
ethylbenzene
m,p-xylene
o-xylene
n-propylbenzene
3-ethyltoluene
4-ethyltoluene
2-ethyltoluene
trimethylbenzene
C4-benzene
Three
Musketeers
Castle
Group
Gang
of
Four
Figure 2 Summed mass chromatogram for regular gasoline
Provides highly
specific identification
of each chemical.

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Target group of key chemicals
We use 58 specific chemicals for analysis, plus visual
inspection of hundreds of other chemicals.
Partial data output

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Target group of key chemicals
Examine patterns of targeted groups for compounds.
In addition, we use 63 specific chemicals for analysis, plus
visual inspection of hundreds of other chemicals.
Partial data output
Good match
Poor match
Not present

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Report of ILRs – Presence or Absence
• All this to say presence or absence of ILR

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How much gasoline can be detected in
a sample?

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Chemistry Matters Inc. 47
Burn Tests
• Develop a test to see how much gasoline can be detected during
a burn test
• Spike with gasoline so it can be detected and within linear range
of instrumentation
• Spiked to 70 grams woodchips (~2.5 ounces)
• Burn to varying degrees (0.5 min, 1 min, 2 min, 4 min)
• Determine where gasoline can no longer be measured
30 sec 60 sec 120 sec 240 sec

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Comfortable with Volumes?
48
What is 100 µL of fluid (0.003 ounces)?
A
B
C
D
250 µL
100 µL
50 µL
25 µL

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Burn Test Results
49
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 50 100 150 200 250 300
Percent Gasoline Remaining
Seconds of Burn Time
Amount of gasoline remaining following ILR burn trials
Burn Tests show ILR residue after relatively short exposure to
intense fire is 5% or less. Linear extrapolation of the line will show
less than 0.1% after 6 minutes.
Can still detect 0.5 µL gasoline after 4 minute burn time!
What happens to the pattern of ILR?

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Added to woodchips

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30s burn time
Approximately 50% of signal is gone

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60s burn time

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90s burn time

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120s burn time

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180s burn time

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240s burn time

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Loss of Distinctive Castle Pattern
57
Fresh 90% weathered
Even if we can quantify these chemicals
without interferences – ratios of
chemicals do not appear to be stable.

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Overall Output
• Recoveries of surrogate standards are examined to ensure sufficient
extraction efficiency
• Each of 63 target chemicals are quantitatively identified, with a
‘similarity match’ to a library example of the chemical measured
• The concentrations of the 63 chemicals are measured
• Patterns of these chemicals and hundreds of other chemicals are
inspected
• Chromatograms assessed to determine the type of ILRs present in the
sample
• All to the ppb to ppt level

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Analytical Chemistry Summary
• Can detect multiple ILRs to the ppb and ppt levels
– Very sensitive methods
• Can distinguish between different ILRs at these
levels
• Methods used by laboratories to determine
potential ILRs are not all equal
• When concentrations of ILRs are high on samples
and matrix effects are minimal, ILR determination
is relatively easy…

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Questions?

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What differentiates a legal case
from a normal investigation?
61
Best practice should be the same for any investigation
regardless of what the ultimate conclusions are used for.

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What differentiates a legal case from a
normal investigation?
62
Increasing pressure for complete documentation of activities to acquire and
submit a sample to meet legal scrutiny:
• Note taking (dedicated scribe recommended)
• Photography
Documentation of the scene
• Videography
Especially as demonstration for sampling techniques or deviations
from normal techniques
• GPS – sub-centimeter preferred
• Chain of custody maintained
Anything that could be questioned, provide proof /documentation on
what was done and where

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Science in the Courtroom
• Collection of samples and
chemical analyses to support
prosecution must follow good
science
– Good laboratory practice
– Solid field sample procedures
– Sound scientific process
• Science is often misunderstood
by the legal profession
• Scientists, lawyers and judges
operate in different worlds

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What differentiates a legal case from a
normal investigation?
64
Demonstration of correct procedures
(sample collection, sample transport)
• How was sample taken?
• Who took the sample? Qualified?
• Where was sample taken? Documented?
• Integrity of sample – preservation and chain of custody
• Chain of custody must be maintained
Must stand up to legal scrutiny!

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Legal Chain of Custody

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What is Legal Chain of Custody?
66
Legal samples require that the physical control or
continuity of a sample be documented from the time it
is taken until the time it is destroyed.

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Maintaining Legal Chain of Custody
67
Sample is under custody if:
• the sample is in a person’s possession
• the sample is in a person’s view after being in possession
• the sample was in the person’s possession and then was
locked up to prevent tampering
• the sample is in a designated secure area
Also includes:
• Taking precautions to prevent sample mix-up
• Providing clear information to laboratory
• Contents in controlled and “monitored”
environment

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Sampling
68
Fundamental sampling techniques and unique
sampling techniques beyond scope of this talk.
Assume:
- Proper training for how to acquire samples
- Proper sample containers are available
- Proper techniques are used to acquire samples
Proper = the right tool for the job

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Sample Label
• Project Name / Case Number / File
Number
• Unique Sample Identifier
• Sample Type / Description of
material
• Date/Time of Collection
• Location of the sample
• Sampler Name or Initials

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Labeling Samples
• Waterproof ink / Sharpie
– Sharpie still smears if
solvents/free product present
• Secondary containment is
good practice
– Especially for high concentration
samples
– Reduces cross contamination
– Second barrier for ice/water
wetting sample
• Two labels required – one for
sample, one for bag

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Field notes and documentation

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Field Notebooks
72
• Waterproof notebooks and
pens highly recommended
• Only use legally defensible
notebooks
– Bound, no ripped out pages,
pages numbered
• www.riteintherain.com

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Notes about Notebooks
73
• Waterproof
• Bound with numbered pages
– Hard spine only
• Each project should have
dedicated notebook (can be
subpoenaed as evidence)
• Field data and observations
recorded in log books

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The Art of Note Taking
74
• Record observations
• No emotions or opinions
• Be very thorough
• Use consistent terminology
• Have standardized points/definitions to
include for each investigation
• Try to remain unbiased with everything
being documented
– e.g.
• “visible burn marks near baseboard consistent with
pour pattern”
• “burn marks near baseboards demonstrate
obvious pour pattern from gasoline found on site ”

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The Art of Note Taking
75
• Each page dated and signed
• All lines are filled (no blank spaces)
• When page finished, jagged line through
remainder of space with note takers
initials
– Cannot leave space for later notes to be
added
• Errors are crossed out with a single line
and initialed by note taker
– Must be able to read the error, no covering
up of evidence

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Sampling Forms
• No empty fields to be filled in
• Data used months to years after
the fact
• Completeness/thoroughness is
key
• Data blanks make it look
incomplete or careless
• Questioning whether procedures
were followed
76
Name Date
Location

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Digital Notebooks Becoming Popular
77
• Standardized programs or customized
programs can be developed and used
for consistency
• Advantages:
– Reports essentially completed in field
– Forced to fill in fields, if standardized
– GPS coordinates (not sub-cm), pictures all
linked
– Can be synced to server while in field
– Looks neat and tidy, no handwriting issues
– Can be weather proofed
• https://www.lifeproof.com/

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Digital Notebooks Becoming Popular
78
• Disadvantages:
– Battery life
– Cold weather can drain battery quickly
– Limitations with annotations, drawings,
sketches

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Photography
79
• Essential for any litigious/adversarial
sampling
• Provides visual for site conditions, site
layout, sampling and sample integrity
• Can be done easily, everyone has
cellphone cameras
– No excuse not to take pictures
• Document anything that can be
questioned
• Photographs taken as soon as possible
during investigation before any
alterations of the scene

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Photography
80
• Camera can be phone, tablet, SLR, or custom digital
GPS camera
– High resolution SLR is preferred
• Pictures can be uploaded later (renaming, organized)
• Must keep a photolog
• Tablet/iPhone can be used with software for
automatic photolog/reporting

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Photography
81
• How many photographs to take?
• What to take pictures of?
• Can you take too many pictures?

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Photographic evidence
82
Story board of sample collection.
Visual prompts for litigation.
Demonstration of techniques.
Sample collection from a failed pipeline for litigation
Document how sampling location was exposed

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Photography – Story Board

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84
• Document how samples were collected
• Pre- and post-disturbance sampling locations
– White board serves as good method to document sample ID and
basic information in picture
– Signage kept in same location and picture taken from same
location
– Pre-disturbance picture with cans/sampling supplies
– Post-disturbance with samples in sampling vessels

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Photography – Must Haves
85
• Location/site should be documented
– North, East, South, West
– GPS location should be recorded for each picture
• Pictures approaching sampling location
• Pictures of sampling location – before and after sampling
• Scale in picture is good practice
• Pictures of samples – sealed for shipment
• Pictures of coolers – documenting sealed cooler with initials
• Complete documentation of removes doubt of how samples were taken.

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Videography
86
• Used in addition to photography
• Video sampling procedure once for
demonstration of what was done on-site
• Any deviations of standard sampling
procedures should be recorded
• Contentious sites/issues should be
completely recorded
http://www.movensee.com/store.html

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Video Log
Unique or Demonstrative Sampling
Techniques

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GPS
88
• GPS cameras available (can triangulate objects
visible in the distance)
• Handheld GPS work
• Phones have GPS available as well
• GPS – use best technique available
– Many people associate precision = accuracy
• Handheld GPS +/- 3-5 m vs. sub-cm

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Transfer of Custody to the Laboratory

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Transfer of Custody
The CoC is the important document.
The receiving person at the lab will check the contents against
the CoC.
The outer vessel (cooler) will be inspected for integrity, and
photographed. Each sample is photographed.
Sign-off and formal transfer of custody.

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Chain of Custody Documentation
A document that lists important information for the
fire debris samples.
• Demonstration of sample control.
• Can be filled out electronically or by hand.
• Often misused and represents a weakness in a
legal case.
• Lawyers love to pick through deficiencies in
CoCs.

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Signature Signature
Filled out to
completion
- No blanks
Arrows look
sloppy – fill
out form
Do not skip
lines for
sample list
Signatures present from sampler,
person dropping off samples, and
laboratory
Date and time on
signature line
Samples on
COC match
samples in
cooler
No empty fields
– can be
construed as
careless
LAB ABC

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Common issues with COCs
• Incomplete fields
• No signatures
• Arrows instead of filling in
• Missing samples/extra samples
COCs are a legal document showing transition of
samples from field to laboratory
Forms need to be filled out properly and completely to
demonstrate proficiency and thoroughness.

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94
Document sample containment securing

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Laboratory Custody
95
• Laboratory should document and handle
samples with similar chain of custody
procedures.
• Samples and extracts should be properly
documented and labeled
• Samples should be stored in freezers until client
allows them to be destroyed which is also
documented.

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Documentation Summary
96
• There is no single method to document a site
• Each organization should develop a standard
procedure followed by all personnel
• Exceptions to the rules may apply
– Only experience can help in these instances
• When in doubt, ASK! It needs to be done right.

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What Not To Do
Potentially litigious samples
submitted for forensic
analysis.

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Questions?

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Where to sample?
• Wildfire pattern experts determine if source of
fire is suspicious
– ‘read the grass’ to determine origin
• Look for tell tale ‘burn patterns’ that indicate
arson may have occurred

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A little help is still required

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Sense of Smell
o As we breathe, air passes over olfactory receptor neurons
that bind to these small molecules to interpret smell
o Small area on top of nasal cavity
o Humans have large range of odour detection capabilities
101
Propyl Acetate
Butyl Acetate

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How does a dog’s nose work?
• Possess up to 300 million
olefactory receptors (6 million in
humans)
• Dedicated olefactory region
which is very large and takes
12% of air breathed in for scent
detection
• Receptors are trained for specific
target compounds
102
www.pbs.org/wgbh/nova/nature/dogs-sense-of-smell.html

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The use of Accelerant Detection Canines
(ADCs)
o ADCs possess excellent capability to detect chemicals commonly
associated with ILRs.
o ADCs exceed field equipment currently available for the detection of
chemicals commonly associated with ILRs.
103
Generalized sensitivity
comparisons:
K-9 – ppt
Human – ppm/ppb
Lab – ppb (but getting to ppt)

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Sample Containers

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Sampling Vessels
Taken from:
E. Stauffer et al, Handbook of Fire
Debris Analysis, 2007.

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Choosing a Sample Vessel
• Need to be durable and have easy availability
• Need to fit the material being sampled
• Fit for purpose
• Needs to be guaranteed clean
106
Environmental Sampling Story

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Sample Vessels for Fire Debris
• Stainless steel cans
– Lined or unlined
• Glass laboratory jars
• Nylon bags/Kapak bags

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Paint Cans for Evidence Collection
• Paint cans were designed to hold
paint
• No where are they checking for
QA-QC for cleanliness for ILR
analysis
• Process to manufacture and line
paint cans meet paint container
requirements, not forensic
evidence collection
• Lubricants are petrochemicals
https://www.alibaba.com/showroom/paint-can-manufacturing-equipment.html

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Stainless Steel Cans
• If using stainless steel cans:
– Get supply from laboratory which pre-cleans cans
(heats them to remove contamination)
– Get enough for investigation only, do not transport
around until needed
– If purchasing from paint store:
• Each batch of cans must be checked for cleanliness, submit
to laboratory for analysis
• May invalidate your ILR results if found to have
contamination

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Sampling Vessels
Preference for unlined heat treated sampling cans.
•Ensures highest degree of cleanliness
•Ensures consistency
• Also heat treated carbon strips used for extraction
Interferences
Target compounds
Inc. flashpoint
Pre-Treatment Post-Treatment
Heat above
extraction
temperature

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Lined vs. Unlined
• No guarantees that epoxy coatings are clean
• They are made for paint, not for forensic
samples
• "A light to medium aromatic product was detected in the empty half-gallon
gold lined cans. This product is classified as an ignitable liquid, and its
presence would affect the laboratory analysis of any debris contained in such
can."
111
https://www.firearson.com/About-IAAI/News/Contamination-Of-Evidence-Cans-Lined-With-Gold-Epoxy-Coating.aspx

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Sample Integrity
Clips and security tabs

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Sample Integrity
Secondary containment in
evidence bags
- Prevents moisture contacting outside
of can
- Provides secondary barrier to prevent
high ILR containing evidence from
contaminating low ILR evidence
- Unfortunately, evidence bags have
glue that contains interferences with
ILR analysis

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Sample Integrity
Trip Blanks
• Pre-cleaned sampling cans are
taken to the investigation site, and
returned to the lab, unopened.
• The cans travel with the other
samples.
• Allows proof that potential cross-
contamination during transport did
not occur.

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Trip Blank Issues
• Trip blanks provide method to look for
cross contamination during field
deployment
– Very common practice in environmental
forensics/sampling
• Empty can with suspended carbon strip
sent into the field with each of sample
coolers
• Passively collects volatile compounds from
when cooler picked up until samples
submitted to laboratory (and analyzed)

© 2016
Sampling Vessels May Leak
116
Bagged Non-Bagged
• Trip blanks were sent to the field with samples for
evidence collection.
• Measured amount of marker compounds present on
carbon strip once returned to laboratory.
Concentration
Days in Field Days in Field

© 2016
Sampling Vessels May Leak
117
• In general, bagged cans better than non-bagged
• Secondary containment helps, but doesn’t eliminate
the problem
• Lighter compounds worse than heavier compounds
C2-benzene C3-benzene

© 2017
Preventing Contamination
119
• Stainless steel cans leak
• Double-containment helps, but does not
prevent/guarantee clean samples
• Only take sample canisters out for investigation, then
return unused to laboratory
• Submit samples as soon as they are collected

© 2016
Sampling
Taken from:
E. Stauffer et al, Handbook of Fire
Debris Analysis, 2007.
From Stauffer:
“Samples that are protected from the fire can better retain
ILR than those that are exposed to the fire.”
“When considering the origin of the fire, the investigator
should not take the most burned part as a sample. If the
substrate is charred completely beyond recognition, there
is little chance that any ignitable liquid has survived.”

© 2016
Acquiring a Sample
• All samples should be acquired in triplicate:
– One for analysis
– One for counter valuation
– One for storage
• Should be collected by duly authorized and trained
personnel
– Is their training documented?
– Sampling SOPs available on site
• Good practice to have witness (2nd party) present
during sampling (dedicated scribe)

© 2016
Sampling Strategy
• Most of arson debris sampling for ILRs is
judgmental sampling
– Is the person qualified to make the judgments?
– Are the judgments being documented – reasons
why?
• Used years later
– Remember that one person’s judgment may be
different than another
• Must be able to defend choices

© 2016
Sampling Strategy
• Composite (forest debris in area) or discrete
(soil core samples)
• Statistical / Judgmental / Opportunistic
Systematic grid

© 2016
Sampling Strategy
• Multiple samples at each flag?
• Sample across potential ‘pour’ pattern (left,
center, right)?
• Just at the flag?

© 2017
Sampling
126
Fundamental sampling techniques and unique
sampling techniques beyond scope of this seminar.
Assume:
-Proper training for how to acquire samples
-Proper sample containers are available
-Proper techniques are used to acquire samples
Proper = the right tool for the job

© 2017
Sampling Fundamentals
• Be cognizant of cross-contamination and spoiling of
evidence
• Wear latex/nitrile gloves for evidence collection. New
pair for each sample
• Use clean, previously unused containers for evidence
• Label properly, completely, and consistently
• Tools used for sampling must be cleaned in between each
use
• Identify and collect appropriate ‘comparison’ sample for
each location. Helps laboratory to identify potential
interferences

© 2017
Cleaning Procedures
• Dry brush to remove particulates
• Wash sampling device with soapy water
• Soap can be checked for interferences by laboratory
• Use a wet brush to remove any stuck on debris
• Rinse thoroughly with water to remove soap
• Rinse with clean water (double rinse) – lab supplied
• Solvent rinse is effective to remove any trace organics
remaining
• Acetone, methanol, isopropanol (laboratory grade)
• Allow to dry
• The higher the amount of ILR, the more important the
cleaning procedures are

© 2017
Where to collect samples?
• Select areas that are protected from thermal impact of fire
• Thermal impact includes pyrolysis, evaporation or both
• ILRs can absorb into substrates included carpet, fabrics
and soil
• Avoid heavily burnt areas (heavily charred)
• Likelihood of ILR survival is low
• Carbon from heavily burnt areas ‘competes’ with
analytical extraction method

© 2016
Sampling
Loss of ILRs:
1. Consumed in the fire as fuel.
2. Lost by evaporation due to heat.
High char samples often do not represent good samples.
An example of charred wood sample.

© 2016
Burn Tests
• Develop a test to see how extraction is impacted by char
• Burn to varying degrees (0.5 min, 1 min, 2 min, 4 min)
• Added internal standards to cans prior to extraction to monitor
extraction efficiency
– Compounds with same structures as marker compounds but have been
isotopically labeled
– Therefore, they behave the same as the marker compounds
30 sec 60 sec 120 sec 240 sec

© 2017
High Char Samples
133
• High char samples can compete with carbon strip
• Burnt wood is essentially carbon, thus attracts compounds
similar to carbon strips
• More charred samples, results in less of target compounds
transferring to carbon strip
0
20
40
60
80
100
120
0 30 60 120 240 360
Percent Recovery
Burn Time (seconds)
Percent Recovery versus Burn Time Ethylbenzene-d10
Benzene, 1,3,5-trimethyl-d12
Benzene, 1,2,4,5,-tetramethyl-d14
Naphthalene-d8

© 2016
Sampling
Best sampling:
1. ILRs often soak into materials and are preserved.
2. Low char material option presents best opportunity to
present ILRs if used.
A good example is a baseboard.

© 2016
Sample Stability
ILR can degrade with time.
Regulated time between collection of sample and
analysis of sample to ensure the sample is
representative of the place and time it was
collected.
Termed “Hold Time”
Low concentrations of ILRs allowed to degrade may
be undetected in analysis = false negative.

© 2016
Sample Stability
Samples require specific preservation activities.
Examples include…
Store samples between 2 and 8oC
- Inhibits bacterial degradation
Get to the laboratory
- Get samples to laboratory as soon
as possible
Store samples in correct sample vessel material
- Should be inert to the chemicals of interest
- Should be free of any potential interferences
”proofed”
- Should be sealed/not leak

© 2016
Thermochron
!30$
!20$
!10$
0$
10$
20$
30$
40$
24!Nov!08$
25!Nov!08$
26!Nov!08$
27!Nov!08$
28!Nov!08$
29!Nov!08$
30!Nov!08$
1!Dec!08$
2!Dec!08$
3!Dec!08$
Date%
Temperature(°C)
Samples
collected
Samples
moved to
freezer
Samples moved to
shipping cooler
Samples
received

© 2016
Tamper Proof Seals
• Samples should be sealed
– Can be tamper-proof seal if needed
• Demonstrates integrity of samples
• Shows intent and professionalism

© 2016
Packing Samples
• Keep “like with like” (fire debris
samples not mixed in with product
samples)
– decrease chance of cross contamination
• Sort samples for laboratory
– Easiest preventable error can happen at
check-in
– Sample Log-In very important connection
between laboratory and field work
• Tape cooler shut and sign the seam
141
f04-03-9780444594242

© 2016
Transport to Laboratory
• Samples in sample jars – in your custody
• Every attempt to prevent degradation and
preserve sample prior to laboratory receipt and
analysis must be taken
• Samples should be kept cool (general between
0oC and 4oC)
• Samples should be hand delivered to the
laboratory if possible
– The less links in the chain, the better

© 2016
Laboratory Analysis
• Laboratory is capable of conducting analysis
• Laboratory certification does not guarantee high quality
data
• Laboratory is competent with legal chain of custody
– Proper legal sample handling procedures
– Minimal links in the chain for legal samples

© 2016
How does 2D-GC-MS Work?
147
Modulator
1st Column 2nd Column
Inlet
Detector
1st Column
2ndColumn
0.25 mm I.D.
0.10 mm I.D.

© 2016
Fourth Dimension?
148
148
40 60 80 100 120 140 160 180 200 220 240 260
500
1000
93
77
39 12167 10750 136
Peak True - sample "L1019714-37 straight:1", peak 435, at 2486 , 1.350 sec , sec
40 60 80 100 120 140 160 180 200 220 240 260
500
1000
93
77
41
12110553 67 136
Library Hit - similarity 836, "à-Pinene"
4D
1D
2D
3D

© 2016
Data Interpretation Outcomes
o Level 1. Determine the presence or absence of an ILR in
a sample of fire debris.
o Level 2. Distinguish the type of Ignitable Liquid.
Classification can be an important aid for fire scene
investigators.
o Level 3. Commonality - Statistical tests can determine if
a group of samples present the same origin of ignitable
liquid.
o Level 4. If potential source fuels are presented for
analysis, advanced chemical analysis and data
interpretation can determine a potential IL source.

© 2016
Conclusions
• Using 2DGC-TOFMS, individual gas station
sources may be identified on evidence samples
• Can reduce interferences providing more
confident identification of ILRs
• Lower detection limits

© 2016
Thank You
Contact Info:
Court Sandau
Cell: 403.669.8566
URL: chemistry-matters.com
Twitter: @Chem_Matters
LinkedIn: ca.linkedin.com/in/courtsandau
Slideshare: www.slideshare.net/csandau

Demystifying the Chain of Custody & Forensic Arson Analysis - IAAI 2017

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