ASTM E3272-23

Standard Guide for Collection of Soils and Other Geological Evidence for Criminal Forensic Applications

SIGNIFICANCE AND USE
4.1 This guide describes good practices for the collection (5), packaging, and preservation (8.3) of soils in criminal forensic investigations. Some of the information in this guide is demonstrated in its companion video, which is available on-line and is intended as a complementary resource to this guide (6).  
4.2 Individual agencies can use this guide to develop agency-specific procedures regarding the collection of soils for forensic applications.
SCOPE
1.1 This standard provides guidance to instruct crime scene professionals in good practices for the documentation, collection, and preservation of soil and other geological evidence for use in criminal investigations. Sampling for environmental geology is outside of its scope. It is designed as a resource for professionals whose job responsibilities include the collection and preservation of soil evidence and for forensic scientists to enable them to advise crime scene investigators.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.3 This standard is intended for use by competent forensic science practitioners with the requisite formal education, discipline-specific training (see Practice E2917), and demonstrated proficiency to perform forensic casework.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Aug-2023
• ICS: 03.100.30 - Management of human resources
• ICS: 07.140 - Forensic science
• Technical Committee: E30 - Forensic Sciences
• Drafting Committee: E30.11 - Interdisciplinary Forensic Science Standards

Relations

• Replaces: ASTM E3272-21 - Standard Guide for Collection of Soils and Other Geological Evidence for Criminal Forensic Applications
• Effective Date: 01-Sep-2023
• Refers: ASTM E1732-24 - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Feb-2024
• Refers: ASTM E2917-24 - Standard Practice for Forensic Science Practitioner Training, Continuing Education, and Professional Development Programs
• Effective Date: 01-Feb-2024
• Refers: ASTM E1188-23 - Standard Practice for Collection and Preservation of Information and Physical Items by a Technical Investigator
• Effective Date: 01-Sep-2023
• Refers: ASTM E1732-22 - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Apr-2022
• Refers: ASTM E2917-19a - Standard Practice for Forensic Science Practitioner Training, Continuing Education, and Professional Development Programs
• Effective Date: 01-Jun-2019
• Refers: ASTM E1188-11(2017) - Standard Practice for Collection and Preservation of Information and Physical Items by a Technical Investigator
• Effective Date: 15-Mar-2017
• Referred By: ASTM E3254-23 - Standard Practice for Use of Color in the Visual Examination and Forensic Comparison of Soil Samples
• Effective Date: 01-Sep-2023
• Referred By: ASTM E3294-22 - Standard Guide for Forensic Analysis of Geological Materials by Powder X-Ray Diffraction
• Effective Date: 01-Sep-2023

Overview

ASTM E3272-23: Standard Guide for Collection of Soils and Other Geological Evidence for Criminal Forensic Applications provides comprehensive guidance for forensic professionals on the best practices for documenting, collecting, and preserving soils and other geological materials as evidence in criminal investigations. Developed by ASTM International, this standard is vital for maintaining the integrity and traceability of geological evidence from crime scenes to laboratories, supporting forensic scientists and law enforcement in building reliable cases. The guide emphasizes the importance of using systematic procedures and proper tools, ensuring samples remain uncontaminated and representative of their original context.

Key Topics

• Soil Evidence Collection: Outlines preferred tools and methodologies for collecting soil samples from various sources, including shoes, vehicles, garments, buried objects, body cavities, and crime scenes. Emphasizes the distinction between collecting questioned and known soils and highlights the importance of representing soil variability at crime scenes.
• Sample Documentation: Provides guidance on meticulous documentation, including scene photographs, sketches with cardinal directions, precise location (including GPS coordinates), and detailed sample descriptions. Proper documentation is essential for establishing evidence provenance and chain of custody.
• Preservation & Packaging: Discusses correct preservation techniques such as air-drying, use of rigid, sealable containers, and separating questioned from known samples to prevent cross-contamination. Guidance is included for handling moist samples and packaging large objects or fragile, layered soil aggregates.
• Sampling Techniques: Details both purposeful and systematic approaches for collecting known and sub-surface soil samples. Offers strategies to account for variability in soil properties at complex crime scenes, including techniques to collect soil from impressions and sub-surface layers.
• Competency and Safety: Stresses that the standard is for use by qualified forensic practitioners with appropriate training (referencing ASTM Practice E2917). Encourages consideration of safety, health, and local regulatory requirements during soil collection, especially when excavating or handling hazardous materials.
• Exclusions: Specifies that environmental geology sampling is not covered. The guide focuses exclusively on criminal forensic applications.

Applications

• Crime Scene Investigation: Provides field investigators with clear steps to collect, label, and transport soil and mineral evidence while minimizing contamination risks. Applicable for outdoor and indoor crime scenes, including those involving buried objects or clandestine graves.
• Laboratory Forensics: Enables forensic scientists to advise investigators and interpret evidence with a documented and transparent chain of custody. Ensures samples are suitable for forensic soil comparison, provenance analysis, and analytical testing.
• Legal Proceedings: Supports admissibility of soil evidence in courts by promoting standardized, defensible methods for evidence handling and preservation.
• Agency Protocol Development: Serves as a model for law enforcement agencies to develop or refine their standard operating procedures (SOPs) related to soil and geological evidence in criminal investigations.

Related Standards

These ASTM standards are referenced for complementary procedures relevant to soil and geological evidence:

• ASTM E1188: Practice for Collection and Preservation of Information and Physical Items by a Technical Investigator
• ASTM E1459: Guide for Physical Evidence Labeling and Related Documentation
• ASTM E2917: Practice for Forensic Science Practitioner Training and Professional Development Programs
• ASTM D6966, D7296, D7144, D5755: Standards for dust, wipe, and micro-vacuum sampling for forensic and environmental testing

Keywords: forensic soils, geological evidence, evidence collection, crime scene investigation, sample preservation, forensic science standards, soil sampling, ASTM E3272-23.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3272 − 23 An American National Standard
Standard Guide for
Collection of Soils and Other Geological Evidence for
Criminal Forensic Applications
This standard is issued under the fixed designation E3272; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Using Wipe Sampling Methods for Subsequent Determi-
nation of Metals
1.1 This standard provides guidance to instruct crime scene
D7296 Practice for Collection of Settled Dust Samples
professionals in good practices for the documentation,
Using Dry Wipe Sampling Methods for Subsequent De-
collection, and preservation of soil and other geological evi-
termination of Beryllium and Compounds
dence for use in criminal investigations. Sampling for environ-
D7144 Practice for Collection of Surface Dust by Micro-
mental geology is outside of its scope. It is designed as a
vacuum Sampling for Subsequent Determination of Met-
resource for professionals whose job responsibilities include
als and Metalloids
the collection and preservation of soil evidence and for forensic
D5755 Test Method for Microvacuum Sampling and Indirect
scientists to enable them to advise crime scene investigators.
Analysis of Dust by Transmission Electron Microscopy
1.2 The values stated in SI units are to be regarded as
for Asbestos Structure Number Surface Loading (With-
standard. The values given in parentheses after SI units are
drawn 2023)
provided for information only and are not considered standard.
D5756 Test Method for Microvacuum Sampling and Indirect
Analysis of Dust by Transmission Electron Microscopy
1.3 This standard is intended for use by competent forensic
science practitioners with the requisite formal education, for Asbestos Mass Surface Loading (Withdrawn 2017)
E1188 Practice for Collection and Preservation of Informa-
discipline-specific training (see Practice E2917), and demon-
strated proficiency to perform forensic casework. tion and Physical Items by a Technical Investigator
E1459 Guide for Physical Evidence Labeling and Related
1.4 This standard does not purport to address all of the
Documentation
safety concerns, if any, associated with its use. It is the
E1732 Terminology Relating to Forensic Science
responsibility of the user of this standard to establish appro-
E2917 Practice for Forensic Science Practitioner Training,
priate safety, health, and environmental practices and deter-
Continuing Education, and Professional Development
mine the applicability of regulatory limitations prior to use.
Programs
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3. Terminology
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.1 Definitions of Terms Specific to This Standard:
mendations issued by the World Trade Organization Technical 3.1.1 aggregate(s) [clump(s)], n—a group of soil particles
Barriers to Trade (TBT) Committee. that cohere to each other more strongly than to other surround-
ing particles.
2. Referenced Documents (1)
2 3.1.1.1 Discussion—Soil aggregates can be natural (a ped)
2.1 ASTM Standards:
or formed by human activities (a clod). Often the genesis of
D6966 Practice for Collection of Settled Dust Samples
evidentiary soil aggregates is unknown, so aggregate is often a
preferred term in descriptions of soil evidence.
3.1.2 alibi location(s), n—a known location suggested or
This guide is under the jurisdiction of ASTM Committee E30 on Forensic
linked to a subject (for example, a subject’s home) that is
Sciences and is the direct responsibility of Subcommittee E30.11 on Interdisciplin-
ary Forensic Science Standards. distinct from the crime scene.
Current edition approved Sept. 1, 2023. Published November 2023. Originally
approved in 2021. Last previous edition approved in 2021 as E3272 – 21. DOI:
10.1520/E3272-23.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on The boldface numbers in parentheses refer to a list of references at the end of
the ASTM website. this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3272 − 23
3.1.2.1 Discussion—The term alibi or alibi location can be 3.1.8 soil core sampler [soil corer; soil probe], n—a device
perceived negatively, but comparisons of geological materials used to collect virtually undisturbed sub-surface soil samples
from alibi locations can be exonerating. Alibi location is used for documenting a soil profile.
in this document to be succinct, however use of this term in
3.1.9 soil profile, n—a vertical section of soil exposed from
documentation of evidence, evidence examination reports, or
the ground surface to a depth of interest. A soil profile can be
courtroom testimony is discouraged.
observed in a freshly dug pit, along a road bank, or in many
other places.
3.1.3 known, adj—of established origin associated with the
matter under investigation. E1732 adapted from Ref (1)
3.1.3.1 Discussion—Known soil samples are intentionally
4. Significance and Use
collected, typically from crime scene or alibi locations, for
4.1 This guide describes good practices for the collection
comparison to a questioned soil sample. Soils are heteroge-
(5), packaging, and preservation (8.3) of soils in criminal
neous mixtures of organic matter and minerals that vary with
forensic investigations. Some of the information in this guide is
depth and across the landscape. Typically, more known
demonstrated in its companion video, which is available
samples are needed to represent the range of variation in soils
on-line and is intended as a complementary resource to this
than are required for manufactured materials. “Reference
guide (6).
sample” is used synonymously in Ref (2).
4.2 Individual agencies can use this guide to develop
3.1.4 provenance, n—a place or origin; specifically, the area
agency-specific procedures regarding the collection of soils for
from which the constituent materials of a sedimentary rock or
forensic applications.
facies are derived, also, the rocks of which this area is
composed.
5. Collection Tools
adapted from Ref (3)
5.1 Collection Tool Materials:
3.1.4.1 Discussion—In the context of forensic provenance
5.1.1 Tools for forensic soil collection should either be new,
examination, geological material is analyzed and interpreted to
disposable items (for example, plastic spoons, swabs, wipes,
estimate or limit the geographic or environmental conditions of
filters) or non-porous tools, cleaned prior to each use (see 5.2)
the source of this material to provide an investigative lead. For
to prevent contamination from either the tool itself or a
example, soil on a shovel can be examined to aid in the search
previously collected sample.
for a clandestine grave, typically by comparison of observa-
5.1.2 Tools for collection of softer materials (for example,
tions to reference data. “Geographic attribution” is an alterna-
unconsolidated sand) can be made of plastic, but for collection
tive term for provenance.
of harder materials, tools made of steel are recommended.
3.1.5 questioned sample, n—material collected as or from
5.1.3 Examples of some non-disposable tools are shown in
items of evidence which have a known location but an
Fig. 1 (see 8.3 for soil evidence packaging materials and
unknown originating source.
recommendations).
(4)
5.2 Cleaning Tools:
3.1.5.1 Discussion—Soil evidence of unknown origin, or
5.2.1 In most circumstances, non-disposable tools can be
questioned soil sample, typically consists of: debris adhering to
cleaned by rinsing with clean water (deionized or distilled are
an evidentiary object or exhibit (3) (for example, tire, wheel
recommended) or with a pre-moistened wipe and dried (pref-
well, garment, shoe, digging tool); foreign soil left at a crime
erably with a lint free material). Pre-moistened wipes are
scene (for example, transferred from a shoe/tire, or adhering to
convenient for cleaning tools during field collections.
a re-buried body/object); or debris recovered from on or within
5.2.2 Alcohol, bleach, or other suitable disinfectant solu-
a body (for example, nasal, stomach, or lung contents).
tions can be used to help with the decontamination of tools
3.1.6 soil, n—sediments or other unconsolidated accumula-
used to collect samples with biological components.
tions of solid particles (for example, minerals and organic
5.2.3 Do not re-use tools that cannot be cleaned.
matter) that are produced by the physical, chemical, and
5.2.4 An item is considered sufficiently clean when no
biological disintegration of parent material, or which has the
particles are seen on a clean cloth used to wipe the tool.
ability to support rooted plants in a natural environment, or
NOTE 1—More rigorous tool cleaning methods are required to achieve
both; and which can include manufactured materials.
DNA-free tools.
adapted from Ref (1)
5.3 Tools for Collection of Questioned Soils:
3.1.6.1 Discussion—Within this document, “soil” includes
5.3.1 For Small Quantities of Questioned Soils (Fig. 1A):
native soil, as well as unconsolidated material emplaced by
human activities.
NOTE 2—These tools can also be used to collect a non-native soil
aggregate from a crime scene.
3.1.7 soil horizon, n—a layer of soil or soil material ap-
proximately parallel to the land surface and differing from 5.3.1.1 Tweezers,
adjacent genetically related layers in physical, chemical, and 5.3.1.2 Forceps,
biological properties or characteristics such as color, structure, 5.3.1.3 Dental picks,
texture, consistency, kinds and numbers of organisms present, 5.3.1.4 Spoons,
degree of acidity or alkalinity, etc. 5.3.1.5 Spatulas, and
(1) 5.3.1.6 Palette knives.
E3272 − 23
NOTE 1—(A, top to bottom) dental pick, micro-spatula, forceps, and spatula; (B) soil corer (with T-handle and two extension rods); (C) trowel.
(Photographs courtesy of Dr. Libby Stern.)
FIG. 1 Some Common Tools Used to Collect Soil Evidence
because their strong adhesives prevent soil recovery and analysis (5).
5.3.2 For Collection of Thin Deposits of Questioned Soil:
5.3.2.1 Spatulas;
5.5.3 Wipes (Practices D6966, D7296); and
5.3.2.2 Ice scrapers;
5.5.4 Swabs (polyurethane is preferable).
5.3.2.3 Clean/new razor blades;
6. Collection of Questioned Soils
5.3.2.4 Other flat tools suitable for prying or scraping the
soil deposit loose; and 6.1 Thoroughly document all questioned soil samples prior
5.3.2.5 Trays, dust pan, cardboard, or paper plates to re- to collection. This includes any depositional (structure or layer)
cover dislodged soil. characteristics (7, 8).
6.2 Refer to 8.3 for methods of packaging and preserving
5.4 Tools for Collection of Known Soils:
soil evidence.
NOTE 3—In most cases, known soils are collected to represent the range
of soil properties present at a location. As a result, known soil samples 6.3 Collection of Questioned Soil on Object of Interest:
tend to be larger than questioned soil samples, requiring larger tools A soil
6.3.1 Objects that have soil evidence adhering to them (for
corer can be used to collect a surface to near-surface soil profile. Smaller
example, shoes, tires, garments) should be documented and
tools, such as pallet knives or tweezers, should be used to collect soils
then collected intact and submitted to the forensic laboratory
from within impressions. A spade or pickaxe are recommended to access
whenever possible. (See 8.3.4 for packaging of soil adhering to
soils from sub-surface, but smaller, like 5.4.1 – 5.4.4 tools are typically
used for collection of known soil specimens. objects.)
6.3.2 If the object cannot be submitted to the forensic
5.4.1 Garden trowels (Fig. 1C);
laboratory, then careful documentation of the soil on the object
5.4.2 Soil corers (Fig. 1B);
should be done prior to the soil removal.
5.4.3 Pointed (archaeologist’s/masonry) trowels;
5.4.4 Spoons;
6.4 Removal of Questioned Soil from Non-Porous Objects
5.4.5 Spades;
When Object Cannot be Submitted Intact:
5.4.6 Mining picks (maddocks, pickaxes, hoepicks); and
NOTE 6—Evidentiary soil can occur on the surfaces and in crevices of
5.4.7 Trays, dustpan, cardboard or paper plates to collect
objects that cannot be delivered to the laboratory.
recovered soil, particularly for subsurface soil collections.
6.4.1 Soil dried on a large hard surface, such as a vehicle,
5.5 Tools for Collection of Dust:
should be documented in place and then pried or scraped off
5.5.1 Particulate filtration cassettes similar to those de-
with a flat tool (5.3.2) onto a clean piece of paper, or onto a
scribed in Test Methods D5755 and D5756 and Practice
clean collection pan, while trying to preserve intact aggregates
D7144;
which can have layering (7, 8).
NOTE 4—Do not use “evidence vacuum filters” because the convoluted
6.5 Removal of Questioned Soil from Porous Objects When
filter material prevents recovery of dust and geological materials.
Object Cannot be Submitted Intact:
5.5.2 Low-tack tapes (similar to 3M Post-it notes); 6.5.1 Remove soil from porous surfaces, such as upholstery,
by gentle scraping with a spatula or similar tool, taking care to
NOTE 5—Do not use high tack tapes or those used to lift fingerprints
preserve intact soil aggregates.
6.5.2 Alternatively, low tack adhesive materials can be used
A trademark of 3M Company in St. Paul, MN. to collect debris loosely attached to the substrate.
E3272 − 23
6.6 Foreign Soil Transferred to a Crime Scene: questioned soil to the known soils and conclude if it is possible
that the questioned soil could have originated from the same
NOTE 7—Foreign soil, or soils derived from another location, can be left
source as the known soil(s). Known soils can also be collected
at a crime scene inadvertently when the soil material, usually as dried
as reference materials in a soil provenance investigation,
aggregates, falls off items such as shoes, tires, or vehicles. Foreign soils
can confirm the location history of a person or vehicle. Evidence
however, the collection strategies described here are primarily
collection teams should seek foreign soil aggregates from locations in or
aimed at collection for soil comparisons.
near tire tracks and shoe prints.
7.2 Surface Versus Sub-Surface Origin Of Questioned Soils:
6.6.1 Collection of foreign soil aggregates found within a
7.2.1 Try to determine if the questioned soil is derived from
shoe or tire impression should be done after documentation of
a surface or sub-surface soil source (for example, soil on a
the impressions by casting, photography or both.
shovel could have originated from soil from beneath the
6.6.1.1 If the foreign soil aggregate adheres to the casting
surface, whereas soil on a shoe or garment is likely to be
material, carefully package the cast and note that this aggregate
derived from soil at the ground surface).
should be recovered in the laboratory.
7.2.2 Prior knowledge of the nature of the questioned soil
6.6.1.2 After documentation of the impression evidence,
evidence and the crime scene will affect the types of known
this questioned soil should be collected along with known soils
soil samples collected.
adjacent to and from within the impression as elimination
7.2.3 Unless there is prior knowledge that the source of a
samples (7.5.3.1).
questioned soil could be from an area such as burial sites,
6.6.1.3 Collect these foreign soil aggregates using a small
holes, river banks, cut banks, or deep tracks or ruts, collection
tools, such as spoons, pallet knifes, or tweezers.
of known surface, rather than sub-surface, soils is recom-
6.7 Questioned Soil On or Within Bodies:
mended. (See 7.6 for surface soil collection and 7.7 for
sub-surface soil collections.)
NOTE 8—Soil on or within a body (for example, under fingernails, on
skin, or within body cavities), or on its clothing, could be probative as an
7.3 Background Information:
indicator of the prior locations of a victim either pre- or post-mortem.
7.3.1 To aid in selection of appropriate known soil samples,
Questioned soil samples associated with a corpse, in particular those soils
acquire domain relevant background information prior to the
recovered from within a body, are often recovered by a medical examiner
or coroner. collection of known soil samples to aid in the selection of
appropriate known soils samples (for example, is it known
6.7.1 Crime scene professionals should coordinate collec-
where the suspect/vehicle had been walking/driving?; has
tions of soil evidence associated with a corpse with the medical
preliminary examination of soil evidence been conducted in the
examiner or coroner.
case to guide known soil sample collection?).
6.7.2 Evidence collection professionals should seek and
7.3.2 Other types of background information that might be
document foreign soils that are associated with a body and, if
useful in guiding collection of known soils include: soil survey
permitted, collect these soil samples prior to removal of the
information; geological survey information; appropriate maps
body from the recovery location.
(including geo-political, topographical, road, vegetation, land
6.7.3 If soil evidence cannot be collected from a body prior
cover, geological, and soil survey maps); and the exact location
to its removal from the scene, then any visible soil evidence
where the questioned sample was collected, including geo-
should be documented photographically, and appropriate per-
graphic (GPS) coordinates or equivalent, such as that obtained
sonnel (for example, medical examiners) should be contacted
with a total-station or orthogonal drone imagery.
about the need to collect and preserve the soil evidence.
6.7.4 Collect additional known soils from the body recovery
7.4 Minimizing Environmental Alteration:
location as elimination samples (7.5.3.1). 7.4.1 Collect and preserve soil samples as early as possible
in the investigation to limit environmental alteration or degra-
6.8 Questioned Soil from Living Persons:
dation over time (5).
6.8.1 A living person (victim or suspect) can have soils on
7.4.2 Collection of additional soil samples might be neces-
or within them (for example, under fingernails, on skin, or
sary at a later date, but these samples might not represent the
within body cavities). These soils might be collected by a
materials that were present at the time of the crime.
medical professional so evidence collection personnel should
communicate the need for soil evidence collection to the 7.5 Known Soil Sample Volume:
medical team and provide guidance on appropriate documen-
7.5.1 When possible, collect approximately 30 mL (2 to 3
tation and packaging. Tbsp) per sample.
6.8.2 The tools used to collect soils from living persons are
7.5.2 Coarse-grained or lower density materials, or both,
likely to be those in a medical facility such as swabs, wipes, such as gravel, pebbles, or soils with high botanical content
tweezers, or tongue depressors; medical specimen cups are
might require a significantly larger sample volume/size; if
useful for soil evidence containment. objects or features larger than approximately 2 mm (or about ⁄8
in.) are present, attempt to collect a volume of soil that is at
7. Collection of Known Soils
least ten times larger in its linear dimensions than the largest
7.1 Known soil samples are purposefully collected to rep- grain or feature (for example, if soil has 4 mm diameter grains,
resent the range of soil characteristics at a crime scene or alibi collect a sample volume greater than ~40 mm × 40 mm × 40
location to enable a forensic soil examiner to compare a mm, or 64 mL, or about one-quarter cup).
E3272 − 23
7.5.3 Number of Known Soil Samples to Collect:
7.5.3.1 The number of known soils samples to collect is
case- and scene-dependent.
NOTE 9—While there is no specific minimum number of samples that
must be collected, some authors have made recommendations regarding
appropriate sample numbers (9, 10). In general, it is recommended to
collect a greater number of samples rather than fewer, with typically 3 to
20 known soil samples collected depending on the site details. Fewer soil
samples are needed if: the crime scene/alibi area is small, there is minimal
variation in topography or vegetation, there are no visual differences in the
soils present, and there is only a single path of ingress and egress. As the
complexity of the scene increases, a greater number of known samples
should be collected to capture the potential variations.
7.5.3.2 Collection of Elimination Soils—When collecting
NOTE 1—Image courtesy of OSAC Geological Materials Subcommit-
questioned soil evidence, it is important to collect known soils
tee.
from the same location to eliminate that site as a possible FIG. 2 Example of a Combination of Purposeful Sampling (Green
Circles
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E3272 − 21 E3272 − 23 An American National Standard
Standard Guide for
Collection of Soils and Other Geological Evidence for
Criminal Forensic Applications
This standard is issued under the fixed designation E3272; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This standard provides guidance to instruct crime scene professionals in good practices for the documentation, collection, and
preservation of soil and other geological evidence for use in criminal investigations. Sampling for environmental geology is outside
of its scope. It is designed as a resource for professionals whose job responsibilities include the collection and preservation of soil
evidence and for forensic scientists to enable them to advise crime scene investigators.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for
information only and are not considered standard.
1.3 This standard cannot replace knowledge, skills, or abilities acquired through education, training, and experience (Practiceis
intended for use by competent forensic science practitioners with the requisite formal education, discipline-specific training (see
Practice E2917), and is to be used in conjunction with professional judgment by individuals with such discipline-specific
knowledge, skills, and abilities.demonstrated proficiency to perform forensic casework.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D6966 Practice for Collection of Settled Dust Samples Using Wipe Sampling Methods for Subsequent Determination of Metals
D7296 Practice for Collection of Settled Dust Samples Using Dry Wipe Sampling Methods for Subsequent Determination of
Beryllium and Compounds
D7144 Practice for Collection of Surface Dust by Micro-vacuum Sampling for Subsequent Determination of Metals and
Metalloids
D5755 Test Method for Microvacuum Sampling and Indirect Analysis of Dust by Transmission Electron Microscopy for
This guide is under the jurisdiction of ASTM Committee E30 on Forensic Sciences and is the direct responsibility of Subcommittee E30.11 on Interdisciplinary Forensic
Science Standards.
Current edition approved Jan. 1, 2021Sept. 1, 2023. Published April 2021November 2023. Originally approved in 2021. Last previous edition approved in 2021 as
E3272 – 21. DOI: 10.1520/E3272-21.10.1520/E3272-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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Asbestos Structure Number Surface Loading (Withdrawn 2023)
D5756 Test Method for Microvacuum Sampling and Indirect Analysis of Dust by Transmission Electron Microscopy for
Asbestos Mass Surface Loading (Withdrawn 2017)
E1188 Practice for Collection and Preservation of Information and Physical Items by a Technical Investigator
E1459 Guide for Physical Evidence Labeling and Related Documentation
E1732 Terminology Relating to Forensic Science
E2917 Practice for Forensic Science Practitioner Training, Continuing Education, and Professional Development Programs
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 aggregate(s) [clump(s)], n—a group of soil particles that cohere to each other more strongly than to other surrounding
particles.
(1)
3.1.1.1 Discussion—
Soil aggregates can be natural (a ped) or formed by human activities (a clod). Often the genesis of evidentiary soil aggregates is
unknown, so aggregate is often a preferred term in descriptions of soil evidence.
3.1.2 alibi location(s), n—a known location suggested or linked to a subject (for example, a subject’s home) that is distinct from
the crime scene.
3.1.2.1 Discussion—
The term alibi or alibi location can be perceived negatively, but comparisons of geological materials from alibi locations can be
exonerating. Alibi location is used in this document to be succinct, however use of this term in documentation of evidence,
evidence examination reports, or courtroom testimony is discouraged.
3.1.3 known, adj—of established origin associated with the matter under investigation. E1732
3.1.3.1 Discussion—
Known soil samples are intentionally collected, typically from crime scene or alibi locations, for comparison to a questioned soil
sample. Soils are heterogeneous mixtures of organic matter and minerals that vary with depth and across the landscape. Typically,
more known samples are needed to represent the range of variation in soils than are required for manufactured materials.
“Reference sample” is used synonymously in Ref (2).
3.1.4 provenance, n—a place or origin; specifically, the area from which the constituent materials of a sedimentary rock or facies
are derived, also, the rocks of which this area is composed.
adapted from Ref (3)
3.1.4.1 Discussion—
In the context of forensic provenance examination, geological material is analyzed and interpreted to estimate or limit the
geographic or environmental conditions of the source of this material to provide an investigative lead. For example, soil on a shovel
can be examined to aid in the search for a clandestine grave, typically by comparison of observations to reference data.
“Geographic attribution” is an alternative term for provenance.
3.1.5 questioned sample, n—material collected as or from items of evidence which have a known location but an unknown
originating source.
(4)
3.1.5.1 Discussion—
Soil evidence of unknown origin, or questioned soil sample, typically consists of: debris adhering to an evidentiary object or
exhibit (3) (for example, tire, wheel well, garment, shoe, digging tool); foreign soil left at a crime scene (for example, transferred
from a shoe/tire, or adhering to a re-buried body/object); or debris recovered from on or within a body (for example, nasal,
stomach, or lung contents).
3.1.6 soil, n—sediments or other unconsolidated accumulations of solid particles (for example, minerals and organic matter) that
are produced by the physical, chemical, and biological disintegration of parent material, or which has the ability to support rooted
plants in a natural environment, or both; and which can include manufactured materials.
adapted from Ref (1)
The last approved version of this historical standard is referenced on www.astm.org.
The boldface numbers in parentheses refer to a list of references at the end of this standard.
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NOTE 1—(A, top to bottom) dental pick, micro-spatula, forceps, and spatula; (B) soil corer (with T-handle and two extension rods); (C) trowel.
(Photographs courtesy of Dr. Libby Stern.)
FIG. 1 Some Common Tools Used to Collect Soil Evidence
3.1.6.1 Discussion—
Within this document, “soil” includes native soil, as well as unconsolidated material emplaced by human activities.
3.1.7 soil horizon, n—a layer of soil or soil material approximately parallel to the land surface and differing from adjacent
genetically related layers in physical, chemical, and biological properties or characteristics such as color, structure, texture,
consistency, kinds and numbers of organisms present, degree of acidity or alkalinity, etc.
(1)
3.1.8 soil core sampler [soil corer; soil probe], n—a device used to collect virtually undisturbed sub-surface soil samples for
documenting a soil profile.
3.1.9 soil profile, n—a vertical section of soil exposed from the ground surface to a depth of interest. A soil profile can be observed
in a freshly dug pit, along a road bank, or in many other places.
adapted from Ref (1)
4. Significance and Use
4.1 This guide describes good practices for the collection (5), packaging, and preservation (8.3) of soils in criminal forensic
investigations. Some of the information in this guide is demonstrated in its companion video, which is available on-line and is
intended as a complementary resource to this guide (6).
4.2 Individual agencies can use this guide to develop agency-specific procedures regarding the collection of soils for forensic
applications.
5. Collection Tools
5.1 Collection Tool Materials:
5.1.1 Tools for forensic soil collection should either be new, disposable items (for example, plastic spoons, swabs, wipes, filters)
or non-porous tools, cleaned prior to each use (see 5.2) to prevent contamination from either the tool itself or a previously collected
sample.
5.1.2 Tools for collection of softer materials (for example, unconsolidated sand) can be made of plastic, but for collection of harder
materials, tools made of steel are recommended.
5.1.3 Examples of some non-disposable tools are shown in Fig. 1 (see 8.3 for soil evidence packaging materials and
recommendations).
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5.2 Cleaning Tools:
5.2.1 In most circumstances, non-disposable tools can be cleaned by rinsing with clean water (deionized or distilled are
recommended) or with a pre-moistened wipe and dried (preferably with a lint free material). Pre-moistened wipes are convenient
for cleaning tools during field collections.
5.2.2 Alcohol, bleach, or other suitable disinfectant solutions can be used to help with the decontamination of tools used to collect
samples with biological components.
5.2.3 Do not re-use tools that cannot be cleaned.
5.2.4 An item is considered sufficiently clean when no particles are seen on a clean cloth used to wipe the tool.
NOTE 1—More rigorous tool cleaning methods are required to achieve DNA-free tools.
5.3 Tools for Collection of Questioned Soils:
5.3.1 For Small Quantities of Questioned Soils (Fig. 1A):
NOTE 2—These tools can also be used to collect a non-native soil aggregate from a crime scene.
5.3.1.1 Tweezers,
5.3.1.2 Forceps,
5.3.1.3 Dental picks,
5.3.1.4 Spoons,
5.3.1.5 Spatulas, and
5.3.1.6 Palette knives.
5.3.2 For Collection of Thin Deposits of Questioned Soil:
5.3.2.1 Spatulas;
5.3.2.2 Ice scrapers;
5.3.2.3 Clean/new razor blades;
5.3.2.4 Other flat tools suitable for prying or scraping the soil deposit loose; and
5.3.2.5 Trays, dust pan, cardboard, or paper plates to recover dislodged soil.
5.4 Tools for Collection of Known Soils:
NOTE 3—In most cases, known soils are collected to represent the range of soil properties present at a location. As a result, known soil samples tend to
be larger than questioned soil samples, requiring larger tools A soil corer can be used to collect a surface to near-surface soil profile. Smaller tools, such
as pallet knives or tweezers, should be used to collect soils from within impressions. A spade or pickaxe are recommended to access soils from
sub-surface, but smaller, like 5.4.1 – 5.4.4 tools are typically used for collection of known soil specimens.
5.4.1 Garden trowels (Fig. 1C);
5.4.2 Soil corers (Fig. 1B);
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5.4.3 Pointed (archaeologist’s/masonry) trowels;
5.4.4 Spoons;
5.4.5 Spades;
5.4.6 Mining picks (maddocks, pickaxes, hoepicks); and
5.4.7 Trays, dustpan, cardboard or paper plates to collect recovered soil, particularly for subsurface soil collections.
5.5 Tools for Collection of Dust:
5.5.1 Particulate filtration cassettes similar to those described in Test Methods D5755 and D5756 and Practice D7144;
NOTE 4—Do not use “evidence vacuum filters” because the convoluted filter material prevents recovery of dust and geological materials.
5.5.2 Low-tack tapes (similar to 3M Post-it notes);
NOTE 5—Do not use high tack tapes or those used to lift fingerprints because their strong adhesives prevent soil recovery and analysis (5).
5.5.3 Wipes (Practices D6966, D7296); and
5.5.4 Swabs (polyurethane is preferable).
6. Collection of Questioned Soils
6.1 Thoroughly document all questioned soil samples prior to collection. This includes any depositional (structure or layer)
characteristics (7, 8).
6.2 Refer to 8.3 for methods of packaging and preserving soil evidence.
6.3 Collection of Questioned Soil on Object of Interest:
6.3.1 Objects that have soil evidence adhering to them (for example, shoes, tires, garments) should be documented and then
collected intact and submitted to the forensic laboratory whenever possible. (See 8.3.4 for packaging of soil adhering to objects.)
6.3.2 If the object cannot be submitted to the forensic laboratory, then careful documentation of the soil on the object should be
done prior to the soil removal.
6.4 Removal of Questioned Soil from Non-Porous Objects When Object Cannot be Submitted Intact:
NOTE 6—Evidentiary soil can occur on the surfaces and in crevices of objects that cannot be delivered to the laboratory.
6.4.1 Soil dried on a large hard surface, such as a vehicle, should be documented in place and then pried or scraped off with a
flat tool (5.3.2) onto a clean piece of paper, or onto a clean collection pan, while trying to preserve intact aggregates which can
have layering (7, 8).
6.5 Removal of Questioned Soil from Porous Objects When Object Cannot be Submitted Intact:
6.5.1 Remove soil from porous surfaces, such as upholstery, by gentle scraping with a spatula or similar tool, taking care to
preserve intact soil aggregates.
A trademark of 3M Company in St. Paul, MN.
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6.5.2 Alternatively, low tack adhesive materials can be used to collect debris loosely attached to the substrate.
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6.6 Foreign Soil Transferred to a Crime Scene:
NOTE 7—Foreign soil, or soils derived from another location, can be left at a crime scene inadvertently when the soil material, usually as dried aggregates,
falls off items such as shoes, tires, or vehicles. Foreign soils can confirm the location history of a person or vehicle. Evidence collection teams should
seek foreign soil aggregates from locations in or near tire tracks and shoe prints.
6.6.1 Collection of foreign soil aggregates found within a shoe or tire impression should be done after documentation of the
impressions by casting, photography or both.
6.6.1.1 If the foreign soil aggregate adheres to the casting material, carefully package the cast and note that this aggregate should
be recovered in the laboratory.
6.6.1.2 After documentation of the impression evidence, this questioned soil should be collected along with known soils adjacent
to and from within the impression as elimination samples (7.5.3.1).
6.6.1.3 Collect these foreign soil aggregates using a small tools, such as spoons, pallet knifes, or tweezers.
6.7 Questioned Soil On or Within Bodies:
NOTE 8—Soil on or within a body (for example, under fingernails, on skin, or within body cavities), or on its clothing, could be probative as an indicator
of the prior locations of a victim either pre- or post-mortem. Questioned soil samples associated with a corpse, in particular those soils recovered from
within a body, are often recovered by a medical examiner or coroner.
6.7.1 Crime scene professionals should coordinate collections of soil evidence associated with a corpse with the medical examiner
or coroner.
6.7.2 Evidence collection professionals should seek and document foreign soils that are associated with a body and, if permitted,
collect these soil samples prior to removal of the body from the recovery location.
6.7.3 If soil evidence cannot be collected from a body prior to its removal from the scene, then any visible soil evidence should
be documented photographically, and appropriate personnel (for example, medical examiners) should be contacted about the need
to collect and preserve the soil evidence.
6.7.4 Collect additional known soils from the body recovery location as elimination samples (7.5.3.1).
6.8 Questioned Soil from Living Persons:
6.8.1 A living person (victim or suspect) can have soils on or within them (for example, under fingernails, on skin, or within body
cavities). These soils might be collected by a medical professional so evidence collection personnel should communicate the need
for soil evidence collection to the medical team and provide guidance on appropriate documentation and packaging.
6.8.2 The tools used to collect soils from living persons are likely to be those in a medical facility such as swabs, wipes, tweezers,
or tongue depressors; medical specimen cups are useful for soil evidence containment.
7. Collection of Known Soils
7.1 Known soil samples are purposefully collected to represent the range of soil characteristics at a crime scene or alibi location
to enable a forensic soil examiner to compare a questioned soil to the known soils and conclude if it is possible that the questioned
soil could have originated from the same source as the known soil(s). Known soils can also be collected as reference materials in
a soil provenance investigation, however, the collection strategies described here are primarily aimed at collection for soil
comparisons.
7.2 Surface Versus Sub-Surface Origin Of Questioned Soils:
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7.2.1 Try to determine if the questioned soil is derived from a surface or sub-surface soil source (for example, soil on a shovel
could have originated from soil from beneath the surface, whereas soil on a shoe or garment is likely to be derived from soil at
the ground surface).
7.2.2 Prior knowledge of the nature of the questioned soil evidence and the crime scene will affect the types of known soil samples
collected.
7.2.3 Unless there is prior knowledge that the source of a questioned soil could be from an area such as burial sites, holes, river
banks, cut banks, or deep tracks or ruts, collection of known surface, rather than sub-surface, soils is recommended. (See 7.6 for
surface soil collection and 7.7 for sub-surface soil collections.)
7.3 Background Information:
7.3.1 To aid in selection of appropriate known soil samples, acquire domain relevant background information prior to the
collection of known soil samples to aid in the selection of appropriate known soils samples (for example, is it known where the
suspect/vehicle had been walking/driving?; has preliminary examination of soil evidence been conducted in the case to guide
known soil sample collection?)collection?).
7.3.2 Other types of background information that might be useful in guiding collection of known soils include: soil survey
information; geological survey information; appropriate maps (including geo-political, topographical, road, vegetation, land cover,
geological, and soil survey maps); and the exact location where the questioned sample was collected, including geographic (GPS)
coordinates or equivalent, such as that obtained with a total-station or orthogonal drone imagery.
7.4 Minimizing Environmental Alteration:
7.4.1 Collect and preserve soil samples as early as possible in the investigation to limit environmental alteration or degradation
over time (5).
7.4.2 Collection of additional soil samples might be necessary at a later date, but these samples might not represent the materials
that were present at the time of the crime.
7.5 Known Soil Sample Volume:
7.5.1 When possible, collect approximately 30 mL (2 to 3 Tbsp) per sample.
7.5.2 Coarse-grained or lower density materials, or both, such as gravel, pebbles, or soils with high botanical content might require
a significantly larger sample volume/size; if objects or features larger than approximately 2 mm (or about ⁄8 in.) are present,
attempt to collect a volume of soil that is at least ten times larger in its linear dimensions than the largest grain or feature (for
example, if soil has 4 mm diameter grains, collect a sample volume greater than ~40 mm × 40 mm × 40 mm, or 64 mL, or about
one-quarter cup).
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NOTE 1—Image courtesy of OSAC Geological Materials Subcommittee.
FIG. 2 Example of a Combination of Purposeful Sampling (Green Circles) Along a Road and Other Areas of Interest Combined with
Systematic Sampling (Blue Circles) Around a Crime Scene
7.5.3 Number of Known Soil Samples to Collect:
7.5.3.1 The number of known soils samples to collect is case- and scene-dependent.
NOTE 9—While there is no specific minimum number of samples that must be collected, some authors have made recommendations regarding appropriate
sample numbers (9, 10). In general, it is recommended to collect a greater number of samples rather than fewer, with typically 3 to 20 known soil samples
collected depending on the site details. Fewer soil samples are needed if: the crime scene/alibi area is small, there is minimal variation in topography
or vegetation, there are no visual differences in the soils present, and there is only a single
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