Footwear and Tire Evidence [615959]

Footwear and Tire Evidence

An Introduction for Non-Practitioners

William J. Bodziak

Bodziak Forensics

Palm Coast, Florida

www.bodziak.com

Footwear and Tire
Evidence IN THE PAST

• Foot and footwear impressions
were man’s first recognized
“evidence” of a person or
animal’s passage

• Later, cart and wagon wheel tracks also left considerable evidence of their passage

Footwear and Tire Evidence:
extent of use

• Used in all countries

• Symposium on Footwear and Tire Evidence in 1994 had
representatives from over 30 countries

• Fingerprints, DNA and Footwear Evidence are now ranked as top three volume categories in UK

• In US, laboratories and CSIs continue to enhance training and efforts to detect, recover and utilize this evidence

Footwear and Tire Evidence:
Occurrence

• When there is a transfer of class
and possibly individual characteristics from a shoe or tire
to a firm or soft substrate

• T wo dimensional: transfer of
accumulated dust, residue, blood,
etc., to firm substrate

• Three-dimensional: impressions in
soft substrate such as soil, mud, sand
and snow

Factors Affecting Detail

• Shoe sole or tire tread condition

• Contaminants – quantity and quality

• Receiving surface type and
condition

• Moisture

• Movement & distortion

• Degradation of impression before
recovery

Examples

Partial to complete
impressions

• Most shoe and
tire impressions
are partial

• Detail retained ranges from very
poor to excellent

Critical Nature of Detection & Recovery of
Evidence

• Only evidence that is found can be
recovered

• Recover all impressions “whenever possible”

• Need to recover properly

• Need to properly evaluate and document evidence at scene

• Is often the only physical evidence remaining at a crime scene!

VaLUE of Footwear and Tire
Evidence

• May identify shoe or tire with
impression

• May eliminate a specific shoe or tire

• May reveal important similar or
dissimilar features in cases which are
not identifications or eliminations

VALUE of Footwear and Tire
Evidence

• May identify brand and style
of footwear or tire based
on crime scene impressions

VALUE of Footwear and Tire
Evidence

• Can potentially size footwear or
tires based on dimensions and/or
outsole and tread design features
of crime scene impressions

VALUE of Footwear and Tire
Evidence

• Tire impressions can be
compared to tires from a suspected vehicle

• Track features can provide substantial information about size of perpetrator’s vehicle – track widths, wheel base, and turning diameter
measurements

• Combined impressions

Value of Footwear and Tire
Evidence

• Can corroborate or
dispute alibis

• May provide information about number of suspects

• Impressions on bank counters, in blood of victim, etc. show direct
relation to crime

Typical Case example

• Bank Robbery by two individuals, both wearing gloves and
full face halloween masks

• One jumps up onto counter with shotgun (recorded with bank camera)

• Flee in Cadillac witnessed and described by elderly couple

• T wo hours later, car apprehended with suspects but no money nor halloween masks in car.

• Converse shoes from one suspect identified with multiple shoe impressions on bank counter.

Detection of Impressions

• Visible impressions

• Impressions found with special
lighting – oblique light and ALS

• Latent footwear impressions located through electrostatic lifting,
powdering, chemical enhancement

• Significantly enhanced with
aggressive approach at scene

Recovering the Evidence

• Original Evidence

• Photography

• Lifting

• Casting

Original Evidence

• Small and portable items
that have been stepped on
such as broken glass, paper,
etc.

• Larger items where recovery may be difficult at scene

Photography

• General Scene – to
document impressions and scene – not for
examination

• Examination Quality
Photograph – for
examination

Proper Lighting

• Lighting is crucial

• Existing lighting or flash
on camera

• Existing light blocked out and oblique light
provided with off camera flash

Bright ambient light
Ambient light blocked
with fllash

Casting

• Use of Dental Stone
to fill three
dimensional
impressions in soil,
sand, snow

(Movie)

Lifting

• Many ways to lift
impressions from two
dimensional surfaces

• Includes gelatin and adhesive lifts,
electrostatic lifts, Mikrosil, dental stone

Chemical Enhancement

• Performed both at
crime scene and in
laboratory

• Many reagents for both bloody and
non-bloody impressions

Known Shoes and Tires

• Must have actual shoes & tires for
proper examination, not just a
photograph or test impression

• Need to know date shoe or tires are obtained versus date of crime
to account for any changes in wear

• Elimination prints or photos of shoes and tires of first responders,
victim, etc. assist in focus on
perpetrator’s impressions

Known Shoe and Tire Impressions

• Known impressions are used to
demonstrate repeatability of
design, size, wear and individual
characteristics and to provide a
comparative aid in the
examination

When no shoes or tire are
recovered

• Data base searches

• Shoe boxes, photographs,
surveillance cameras, witness
statements, etc.

• Sizing of shoe or tire impressions

Examiner Qualifications

• Minimum recommended requirements of training and experience
(per SWGTREAD)

• Bachelor’s degree in physical or natural science recommended

• Extended formal training program with qualified principal trainer. Should include all relevant topics in field and be documented in training log.

• Regular & sufficient casework experience under training examiner

• Proficiency testing

• Experience, experience, experience!!!

Examiner Certification

• Certification through the International Association for
Identification (IAI)- accredited by the FSAB

• Must be primarily employed in the field of Forensic Science
whose duties include the examination of footwear impression
evidence

• Bachelor’s degree recommended plus three years experience as a footwear examiner (or equivalents)

• Must have satisfactorily completed a training program in this
field

Examiner Certification (continued)

• Certification through the International Association for
Identification (IAI)

• T wo letters of endorsement

• Must pass written test

• Must pass practical examinations

• Must take new practical test and accumulate continuing education points every five years to be “Re-Certified”

Professional AFfiliation and Continued
Education

• Examiners should actively participate in national and/or regional
forensic science organizations for the purpose of continuing education

• International Association for Identification (IAI)

• American Academy of Forensic Sciences (AAFS)

• Regional Forensic Science organizations (MWAFS, SWAFS, IAI state chapters,
etc.)

• European Meetings

• Special classes and workshops

Examination

• Shoes or tires and their known
impressions, measuring devices, magnification, enhancement

• Comparison includes overlay and/or side by side; replication of characteristics; documentation
• Hypotheses

• Shoe or tire made impression

• Shoe or tire did not make
impression

Characteristics Examined

• Design and Physical
Size of Design

• Specific vs General Design

Size 9 Size 9

Characteristics
Examined

• Some complex issues with
regard to size and design require knowledge of mold
making and possible
information from manufacturer

Characteristics Examined

• General wear – the gradual erosion
of rubber due to frictional forces

• Wear creates visible changes in
appearance of shoe or tire and the
impressions they leave

• Agreement in general wear further reduces number of tires or shoes that could have made impression

Characteristics Examined

• Individual Characteristics

• Anything randomly added
to or taken away from the
shoe or tire

• Cuts, scratches, stones
held in tread, tears, tar, gum, nails, patches, etc.

• Required for Identification

Conclusions in Footwear and Tire Evidence
Examinations

• Conclusions range from “Elimination” to “Identification”

• Should be stated and supported on a case by case basis with
demonstrable features

• Discourage use of pre-determined terminology and vague and non-specific conclusions such as “the shoe and impression are consistent with each other” or “the shoe cannot be eliminated”

Example of Identification

 Identification is made
when, in the opinion of the examiner, a set of clear, confirmable and
demonstrable class and
individual characteristics exists, that would not be
repeated in another shoe.

EXAMPLE OF IDENTIFICATION

EXAMPLE OF IDENTIFICATION

Bloody Footwear Impression
on Bundy Walkway Impression with Overlay
of Size 46 Bruno Magli

Success of Examination Depends on:

• Amount of detail retained in impression

• Original impression always had the most detail

• Amount of detail recovered from crime scene

• Varies depending on equipment, experience, resources

• Equipment / standards used in comparison

• T est impressions, standards, lighting, enhancement, etc.

• Expertise / methodology of examiner

Tire Examinations

• Tires are significantly more
complex than rubber shoe soles

• Tires are dynamic – actually change
slightly in dimension when traveling
over different surfaces

• Require additional knowledge, experience and skills beyond footwear examination expertise

• Additional knowledge also required for proper documentation and recovery of this evidence

SWGTREAD TERMINOLOGY

• Identification – this is the highest degree of association
expressed in footwear and tire impression examinations. This
opinion means that the particular shoe or tire made the
impression to the exclusion of all other shoes or tires.

• Probably made (very high degree of association) – this
opinion means that the evidence is very persuasive that the
shoe or tire made the impression, yet some critical feature or quality is lacking and/or missing so that an identification is
not in order.

SWGTREAD TERMINOLOGY

• Could have made (significant association of multiple
class characteristics) – this opinion means that the design
and physical size correspond, and there may also be some
correspondence of the general condition of wear
• Inconclusive (limited association of some
characteristics) – this opinion means some similarities are
noted; however, there are significant limiting factors in the questioned impression that do not permit a specific
association between the questioned impression and the
known shoe or tire.

SWGTREAD TERMINOLOGY

• Probably did not make (very high degree of non-
association) – this opinion means that the evidence is very persuasive that the shoe or tire did not make the impression,
but the impression lacks sufficient quality or clarity for an
elimination.
• Elimination (definite exclusion) – this is the highest degree
of non association expressed in footwear and tire impression examinations. This opinion means that the particular shoe or
tire did not make the impression.

Footwear and Tire Evidence: In
Court

• Records of use in court exist from
1700s

• Universally used in investigations and accepted in courts in U.S. and
around world

• FBI lab used this evidence and
maintained reference files since its
inception in 1932

Requires properly Trained Expert to
Evaluate

• The argument that anyone can perform these exams and
evaluate this evidence properly is wrong

• Research and experience has confirmed that layman or
insufficiently trained persons are not equipped to reach proper
conclusion

• Experts in court should be tested extensively on their specific qualifications of training and experience

• Judges tend to allow unqualified “experts” to testify with weight
going to jury

Daubert Factors

• Daubert court gave guidelines that trial courts should consider /
Kumho said guidelines were meant to be helpful to trial judges

• Not all are required

• Proof of testing of basic underlying hypotheses upon which the technique rests

• Peer review and publications

• Known or potential error rate

• Existence of an accepted methodology

• General acceptance of the technique in the forensic community

The NAS Report & Research

• No practitioners were on committee of the NAS study

• SWGTREAD response published ( www.swgtread.org )

Research

• Research has been conducted and continues to be needed to
test new materials, techniques and procedures.

• Funding requested from Congress should go towards research
that is identified by examiners as “needed” versus research that
is proposed by those in academia that have no understanding of these examinations and what would enhance the performance of that discipline

• Research in any forensic discipline is always welcome and needed
but must include practitioners playing major roles

• A certified examiner should be a major player in that research

• Established in 2004

• T o standardize and advance the forensic analysis of footwear and
tire evidence

• Provides a professional forum where examiners can share knowledge, evaluate practices, develop standards, and identify research needs

• Meets twice yearly

• Is open to your comments, suggestions and other input

Other Resources

• Books

• Footwear Impression Evidence:
Detection, Recovery and Examination (Bodziak, W.J., CRC Press, 2000)

• Tire Tread and Tire Track Evidence (Bodziak, W. J., CRC Press 2008)

• Traces De Souliers (Girod, A., Champod, C. Ribaux, O., France, 2008) (In French)

• Footwear Identification (Cassidy, M.J., RCMP 1980)

• Recommended Course of Study

Other Resources

• Journals

• Journal of Forensic Identification
(IAI)

• Forensic Sciences International

• Journal of Forensic Sciences (AAFS)

• Others

Clear gelatin lift of fluorescent
powder impression on bank
counter
Reverse photograph of
suspects shoe identified with
lift

Before
Enhancement
Amido Enhanced
B/W photo w/red
filter
Case Example

Tire CASE EXAMPLE

This piece was reassembled with other
smaller pieces of the original cast.

Obtaining Inked Known Standards from
Truck Tires

• An inked board is prepared that
is longer than the tire’s
circumference.

• A similar sized board is prepared
over which clear film will be
taped to received the inked
impression.

• The result is a full circumference
clear inked impression.

Examination of Tires and Inked Impressions
with Cast Impression

• Tire designs are made up of a
series of tread blocks.

• These tread blocks vary in size
and arrangement around the
circumference of a tire to help reduce noise.

• Their combined size and
arrangement usually never repeats
and is different on each side of the tire.

Examination of Tires and Inked Impressions with
Cast Impression

• Each inked impression is passed
over the cast to locate areas where the tread block sizes and
arrangement correspond.

• When found, the segment of the
tire represented by the inked impression is compared directly with that segment of the tire.

Examination of Tires and Inked Impressions
with Cast Impression

• Only one segment of each
tire was found to have a corresponding arrangement
of tread block sizes.

Examination of Tires and Inked Impressions
with Cast Impression

• The area defined by blue tape is
the segment of the right rear tire which corresponds with the
crime scene cast.

Examination of Tires and Inked Impressions
with Cast Impression

• The segment of the right rear tire
was found to contain a “stone
hold” i.e., a stone wedged in between two tread blocks.

• It is present in both the cast and
the exact position in the tire.

• The left rear tire and the front tires did not have this
characteristic.

Conclusion

• The right rear tire
corresponds in tread design, tread dimension and general
condition of wear

• It also shares a stone hold of
similar dimensions and shape in the same precise location as the cast .

Photograph of segment of right
rear tire overlaid on top of the
cast to show correlation of stone
hold.

Conclusion

• It is probable this tire made the
cast crime scene impression.

• Only another tire of the same
tread design, dimension and
general condition of wear, and possessing a stone hold with
similar features and held in the
same precise position in the tire’s tread, could have made this impression

Photograph of segment of right
rear tire overlaid on top of the
cast to show correlation of stone
hold.