(*) Minister of Interior, Italian State Police, Forensic Science Department

• CRIME SCENE

• EVIDENCES AND USEFUL INFORMATION FOR INVESTIGATION

• PURPOSE OF THIS WORK

• A, B, C, D, COLLECTED SAMPLES

• ANALYSES PROCEDURES AND METHODOLOGY

• RESULTS AND CONCLUSION

SUMMARY

In the year 2005, in a small village near Rome, a young woman was found dead in her home.

Near the body, the police found two muddy footmarks.

The Police collected two samples on the crime scene: the mud from footmarks and victim’s shoes.

CRIME SCENE

Some neighbours reported to the police that the evening before the crime, Laura quarreled with her boyfriend and that they used to do that very often.

In the boyfriend’s home, the investigators found a pair of shoes dirty of mud, and collected them.

The Police carried out a survay on the suspect’s car, the pedals were dirty of mud and the pedals were collected.

The Police collected the two samples.

INFORMATION FOR INVESTIGATION

•to make a comparison between the mud collected on the crime scene, with the mud adhering on the pedal’s car and the soil adhering on the suspect’s shoes

•to demonstrate differences or analogies among the samples

•to prove if the suspect has been on the crime scene.

THE PURPOSES OF THIS WORK ARE:

SAMPLE A

VICTIM’S SHOES

SAMPLE B

SOIL NEAR THE BODY

SOIL ADHERING ON THE SUSPECT’S CAR

SAMPLE C

SAMPLE D

THE SUSPECT’S SHOES

ANALYSES PROCEDURES AND

METHODOLOGIES

• MACROSCOPIC DESCRIPTION

• S.E.M. ANALYSES

• GRAIN SIZE SEPARATION

• XR DIFFRACTOMETRIC ANALYSES

• THIN SECTION ANALYSES BY MEANS OF A POLARIZING MICROSCOPE

• THERMOGRAVIMETRIC ANALYSES

MACROSCOPIC DESCRIPTION

S.E.M. ANALYSES

GRAIN SIZE ANALYSES

W%

PHI

SAMPLE A

Quartz, Plagioclase, Calcite, Muscovit

SAMPLE B

Quartz, Plagioclase, Calcite, Muscovit

SAMPLE C

Quartz, Plagioclase, Calcite, Muscovit

SAMPLE D

Quartz, Plagioclase, Calcite, Muscovit

XR DIFFRACTOMETRIC ANALYSES

MINERALS A B C D

CALCITEX X X X

QUARTZX X X X

ORTOCLASEX X X X

MICROCLINEX X X X

PLAGIOCLASEX X X X

MICA GROUPX X X X

CLINOPYROSSENOIDX X X X

TOURMALINEX - - -

GLAUGONITEX - X -

GARNETX X X X

ANPHIBOLE- - X X

OXIDE IRONX X X X

POLARIZING MICROSCOPE 1

SEDIMENTARY ROCKS A B C D

MICRITIC LIMESTONE X X X XSPARITIC LIMESTONE X X X XORGANIC LIMESTONE X X X X

CALCARENITE X X X XSANDSTONE X X X X

FLINT STONE X X X X

METAMORPHIC

ROCKS

A B C D

SCHISTS X X X XQUARTZITES X X X X

MICROFOSSILS A B C D

MICROFORAMINIFERS X X X X

MINERALS SAMPLE A SAMPLE B SAMPLE C SAMPLE D

QUARTZ56,5 54,9 48,3 46,2

PLAGIOCLASE GROUP0,8 1,0 0,6 0,7

FELDSPAR GROUP15,6 15,8 18,4 13,2

MICA GROUP1,4 1,4 0,9 1,2

IRON OXIDE0,8 1,2 0,8 1,4

SEDIMENTARY ROCKS

LIMESTONE15,5 15,5 16,2 25,7

SANDSTONE3,2 3,5 4,8 4,2

FLINSTONE3,1 2,9 2,3 2,6

METAMORPHIC ROCKS

QUARTZITES3,1 3,8 7,7 4,7

POLARIZING MICROSCOPE 2

POLARIZING MICROSCOPE 3

THERMOGRAVIMETRIC ANALYSES

•MACROSCOPIC DESCRIPTION: Colour, morphology, vegetables fragments and fibres have very similar features in each samples, especially between B and C samples

•S.E.M. ANALYSIS:The grains of the samples A, B, C, D have the same chemical composition

•ANALYSIS AND GRAIN SIZE SEPARATION:The grains of the samples A, B, C, D have very similar size (sand and silt)

•XR DIFFRACTOMETRIC ANALYSIS:The samples A, B, C, D have the same mineral phases

•THIN SECTION ANALYSIS BY MEANS OF POLARIZING MICROSCOPE:The thin section analyses show the same minerals, rocks fragments and microfossils in all samples, with small differences among them

•THERMOGRAVIMETRIC ANALYSIS:Thermogravimetric analyses show features with high analogy among all the samples, except for the sample A.

RESULTS DISCUSSION

THE ANALYSES SHOWED THAT THE SAMPLES A,B, C, D HAVE:

• HIGH ANALOGY IN INORGANIC COMPOSITION (MINERALS AND ROCK FRAGMENTS)

• HIGH ANALOGY IN ANTHROPIC COMPOSITION (FIBRES)

• HIGH ANALOGY IN ORGANIC COMPOSITION (VEGETABLES).

THE ANALYSES APPLIED ON THE SOIL STUDY,GAVE THE INVESTIGATORS THE EVIDENCE IN ORDER TO LINK LAURA’S BOYFRIEND WITH CRIME SCENE.

CONCLUSION