Geological evidence can be used in a variety of legal and criminal investigations. Forensic geologists analyze soil, rocks, minerals and other earth materials to link a suspect or crime scene to a source area. Trace evidence like rock fragments, soil, and microfossils can be found at crime scenes, on victims or weapons. The Locard's principle of exchange states that contact between two objects results in a transfer of materials. Geological evidence is often overlooked but can help determine what happened at a crime scene and connect suspects. Proper collection, analysis, comparison and documentation of geological samples is important for legal proceedings.

1. Review Article

2. • Application of earth science to legal matters1
• A forensic geologist identifies, analyzes, and
compares earth materials, such as soil, rocks,
minerals, and fossils found on or in a receptor
to possible source areas.2
• Assisting the police to search for homicide
graves1

4. Geological trace evidence includes2 :-
• Rock fragments
• Soil and sediments
• Geological raw materials like bricks, concrete,
glass, plaster board.
• Microfossils
• Etc.

5. • At scene of crime
• On and around dead body
• On the weapon or tool of offence
• In the Suspect vehicle
• In the Medium of transfer (i.e. water)2

6. Geological evidences is based on the principle that
when two objects make contact, there is transfer of
materials from one object to other object. This is
famously called as the Locard’s principle of
exchange,given by Dr.Edmund Locard in 1929.1

7. • Present on almost all crime scenes.
• Being minute, they are unnoticed by culprit and
remain undestroyed, undisturbed and unmutilated.
• Helps to determine corpus delicti.
• Helps to link suspect with scene of crime.
• Can indicate the profession of suspect or victim.
• Helps to reconstruct the sequence of events and the
modus operandi.3

8. Purpose is to
• Obtain evidence for prosecution
• Gain intelligence
• Deprive criminals of their resources and opportunities
• Locate vulnerable persons
• Protect potential target
• Search for homicide grave and associated buried
items or objects1

9. Methods
• Offensive search
• Defensive search 1

10. Factors influencing search
• Weather conditions
• Type of terrain
• Press and media interferences
• The public and communities
• The victim’s family members and friends
• Search area1

11. • Geomorphological mapping
• Remote sensing,
• Analysis of high resolution air photographs,
• Geophysics,
• Hydrochemistry & geochemistry,
• Police dogs, often known as ‘cadaver dogs’, ‘victim
recovery dogs (VRD), or ‘human remains dogs’
(HRD) 1

13. • Photography :- All evidences should be
photographed before attempting any other
method.
• Hand-picking :- The macro-evidences are picked
using forceps and packed in airtight plastic bags.
• Tape lifting :- The evidences are lifted using
tape.
• Scraping :- Evidences like wet mud are scraped
using a sharp tool and collected.
• Casting :- Three dimensional impression of
barefoot and footwear are created using casting
techniques. 3

14. • Comparison & Superimposition
• Microscopy
• Micro-chemical analysis
• X-ray spectroscopy
• IR-Microspectrophotometry3

15. (a)Information on the
Geology
Soil characteristics
Groundwater
Rock types
(b) Demonstrate the level of
Difficulty or ease to dig shallow grave
Time required
Depth which can be achieved

16. (c) Demonstrate how effectively
Soil can be reinstated
Visible topographical features
Possible presence of the grave
(d) Provide a prediction for
Length of time for offender to dispose
of the body. 1

17. 1. Under-fender dirt/soil deposited on the road
At impact area with the victim
For locating car/driver
2. Matching grease on victim with
Grease under the car
To support evidence 2
I. Hit & Run cases:

18. II. Murder:
Geological evidences
Determine primary crime scene
Action of any medium like water
For movement of dead body
Clandestine graves
Weapon of offense 2

19. III. Rape:
Soil on clothing of a suspected rapist
To place the suspect at the crime scene
To eliminate the suspect's alibi 2

20. IV. Environmental Evidence:
1. Groundwater Contamination
2. Surface Water Impacts
3. Wetlands
4. Land subsidence2

21. V. Subsurface Investigations:
1. Locate buried objects
2. Mineral Resources
VI. Insurance Claims - Accidents /
Personal Injury:
1. Vehicle Accident
2. Excavation/Trench Collapse
3. Subsurface Explosion2

22. VII. Insurance Claims - Property
Damage:
1. Vandalism
2. Flood Damage
3. Chemical Exposure
VIII. Case Settlement:
1. Dispute2

23. • Basics of geoforensics and their applications like
evidences, principle, searching, methods, analysis
etc.
• They have varied applications for outdoor crimes.
• Due to lack of information and training, geo-
forensic evidences are often not used
• Let us hope that the future world will recognize
its importance and use it extensively

24. 1. Dr. Laurence J. Donnelly, The role of geo-
forensics in policing and law enforcement,
www2.le.ac.uk/departments/.../Emergency%20Globa
l%20FINAL.pdf
2. Robert A. Hayes, CPG, Forensic Geologists
Uncover Evidence In Soil And Water,
http://www.geoforensics.com/geoforensics/fgeology.
html
3. Dr. B.P. Maithil, Physical investigation in criminal
investigation and Trials