Fingerprint evidence found at crime scenes provides more leads and stronger evidence in court than all other forensic techniques combined. This presentation summarizes various fingerprint development techniques used by forensic experts. It describes techniques like physical developer, ninhydrin, iodine fuming, and cyanoacrylate fuming that are used to visualize latent fingerprints on different surfaces. The presentation explains the principles behind each technique and their advantages and limitations. It provides examples of how techniques like vacuum metal deposition and silver nitrate treatment work at the molecular level to reveal hidden fingerprint residue.
VSC VIDEO SPECTRAL COMPARATAOR FORENSIC APPLICATIONS BY SHAILESH CHAUBEY STUDENT OF FORENSIC SCIENCE & CRIMINOLOGY FROM BUNDELKHAND UNIVERSITY JHANSI UTTAR PRADESH INDIA . THIS PPT SHOWS ABOUT THE FEATURES, APPLICATIONS , CASE LAWS & NEED OF VSC IN FORENSIC ASPECTS FOR DOCUMENT EXAMINATION & HANDWRITING . THIS PRESENTATION WILL HELP TO GET MORE INFORMATION ABOUT VSC BY VARIOUS SLIDES.
VSC VIDEO SPECTRAL COMPARATAOR FORENSIC APPLICATIONS BY SHAILESH CHAUBEY STUDENT OF FORENSIC SCIENCE & CRIMINOLOGY FROM BUNDELKHAND UNIVERSITY JHANSI UTTAR PRADESH INDIA . THIS PPT SHOWS ABOUT THE FEATURES, APPLICATIONS , CASE LAWS & NEED OF VSC IN FORENSIC ASPECTS FOR DOCUMENT EXAMINATION & HANDWRITING . THIS PRESENTATION WILL HELP TO GET MORE INFORMATION ABOUT VSC BY VARIOUS SLIDES.
Fingerprint - Everything You Need To Know About FingerprintsSwaroopSonone
A detailed fingerprint presentation. Fingerprint is one of the most important criminal investigation tools due to their two significant features- uniqueness and persistence. The unique features of friction ridge skin persist from before birth, i.e. during fetal development to the decomposition after death...
A digital imaging instrument manufactured by Foster + Freeman that employs combinations of light sources and filters to examine document evidence under various wavelengths of radiation ranging from ultraviolet to the infrared regions of the electromagnetic spectrum.
VSC is a preferred tool as it supports non destructive examination of documents. VSC uses multiple parameters like IR, UV, and White light providing accurate results.
DEFINATION
Any material can develop significance in crime scene is physical evidence
Locard’s Exchange Principle
Locard’s Principle
Types of Evidence
Trace Evidence
Trace Evidence
Trace Evidence can be Fragile and Easily Lost
Transfer Evidence
Indented or Impression Evidence
Fingerprint - Everything You Need To Know About FingerprintsSwaroopSonone
A detailed fingerprint presentation. Fingerprint is one of the most important criminal investigation tools due to their two significant features- uniqueness and persistence. The unique features of friction ridge skin persist from before birth, i.e. during fetal development to the decomposition after death...
A digital imaging instrument manufactured by Foster + Freeman that employs combinations of light sources and filters to examine document evidence under various wavelengths of radiation ranging from ultraviolet to the infrared regions of the electromagnetic spectrum.
VSC is a preferred tool as it supports non destructive examination of documents. VSC uses multiple parameters like IR, UV, and White light providing accurate results.
DEFINATION
Any material can develop significance in crime scene is physical evidence
Locard’s Exchange Principle
Locard’s Principle
Types of Evidence
Trace Evidence
Trace Evidence
Trace Evidence can be Fragile and Easily Lost
Transfer Evidence
Indented or Impression Evidence
Enhanced ridge structure for improving fingerprint image quality based on a w...LogicMindtech Nologies
IMAGE PROCESSING Projects for M. Tech, IMAGE PROCESSING Projects in Vijayanagar, IMAGE PROCESSING Projects in Bangalore, M. Tech Projects in Vijayanagar, M. Tech Projects in Bangalore, IMAGE PROCESSING IEEE projects in Bangalore, IEEE 2015 IMAGE PROCESSING Projects, MATLAB Image Processing Projects, MATLAB Image Processing Projects in Bangalore, MATLAB Image Processing Projects in Vijayangar
Fingerprint recognition is an important
biometric technology, and its use is increasing day by day.
Fingerprint recognition is affected by several physiological
factors like age, wear and tear of skin, and technological
factors like sensor technologies. This paper builds on
previous research in the area of gender differences in
fingerprint features, and reports results of differences in
performance of fingerprints collected from males and
females. The researchers propose a fingerprint analysis
framework for testing differences in gender and apply the
framework to fingerprints collected from males and
females.
Fingerprints are common evidences found at the crime scene. This presentation include methods for development of latent fingerprints.
To know more about the topic, follow the link given- https://youtu.be/yQjxkntFH0k
Fingerprint is an important evidence found at the crime scene, but in most of the cases, these are not visible to naked eyes. To make these visible we use different methods. Some of these methods are explained in this ppt.
To know more about the topic, clink on the link- https://youtu.be/ky58Byef-D4
Manicure preparations - nail polishes, nail enamel removers, nail art (definitions, formulations, method of preparation, pictures, evaluations) Dosage form
A dental impression is a negative imprint of hard (teeth) and soft tissues in the mouth from which a positive reproduction (cast or model) can be formed. It is made by placing an appropriate material in a stock or custom dental impression tray which is designed to roughly fit over the dental arches. Impression material is of solid or semi-solid nature when first mixed and placed in the mouth. It then sets to become an elastic solid (usually takes a few minutes depending upon the material), leaving an imprint of person's dentition and surrounding structures of the oral cavity
It occurs when a hard, rough surface slides along a softer surface and cuts a series of grooves.
The wearing away of a substance or structure through a mechanical process, such as grinding, rubbing or scraping .
Polishing is production of smooth mirror like surface without use of any external form.
Similar to conventional methods of fingerprint development (20)
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
1. Presented by:
Farah Arooj
Hassan Abdul Qadir
Presented to:
Dr. Zafar Iqbal
Institute of Biochemistry &
Biotechnology, University of
Punjab.
2. “Fingerprints found at crime scenes lead to more suspects
and generate more evidence in court than all other forensic
techniques combined.”
Interpol European Expert Group on Fingerprint Identification (IEEFG) Methods for Fingerprint
Identification Part 1 (2004
3. • Friction ridges on hands are known for
thousands of years
• First suggested by Dr. Henry Flaud in 1880
• The use of chemical compounds for the visualization of
latent prints dates back only about 150 years
• Most commonly used technique for identification of
criminal.
5. • Visible print by unaided eye.
• Example: A good example of a patent print
would be a greasy impression left on a window.
• Also in blood, paint, ink, mud or dust
• These are formed when the raised friction ridges are
physically pushed into the substrate, creating a mold of the
friction skin ridge Clay, soft wax, melted plastic,
heavy grease, and paint
6. • Good source of imaging for
patent prints
• Plastic impressions are usually
photographed under oblique lighting
that enhances the contrast of the ridges
and furrows.
• These prints may also be preserved with silicone-type
casting materials.
7. • The word latent means hidden or
unseen.
• Latent prints are undetectable until brought out with a
physical or chemical process designed to enhance latent print
residue.
• Affected by age, gender, stimuli, occupation, disease, and any
substances the subject may have touched prior to deposition.
• After deposition: surface area, surface curvature/shape,
• surface temperature, humidity, time since they were placed
and temperature.
8. • Help in understanding working of chemicals and
developing new reagents.
• A latent print residue is mixture of secretion from glands.
• 2 major glands in dermis sebaceous glands and
sudoriferous glands (eccrine and apocrine).
• The print is 99% water and rest is trace amount of amino
acids, lipids urea, lactic acid, creatinine, glucose and
drugs.
• 250 ng of amino acid per fingerprint. They
remain there after water evaporates.
9. • Finely divided particles that physically adhere to the
aqueous and oily components in latent print residue on
nonporous surfaces.
• One of the oldest and most common methods of latent
print detection (1891).
• They have affinity for moisture and oily components in a
print causes adhesion
2 components.
• Pigment (for visualization)
• Binder (for adhesion to latent print residue) (Menzel,
1999, p 143).
10. • Pigments included lampblack , antimony trisulfide, lead
iodide, lead oxide mercuric oxide ,mercuric sulfide
• Adhesive materials included starch, kaolin, rosin, and
silica gel
• Available in different colors
Visualization
Is done by reflected/absorbed light or fluorescence
Application
By soft fluffy brush with fine hairs usually made of animal
skin. Stiff brushes can damage the latent residue
11. • Consists of charcoal and binder.
• Applied on light colored surfaces. Even
Show up on black glossy surfaces as light
color
• Produce dark gray image
• The powder is taken by brush and gently
roll on surface. Excess powder is dusted out.
The developed fingerprints are preserved
On transparent tape.
12. • Inexpensive
• Covers a large area
• Less substrate painting
Disadvantages
• Creates mess
• Cannot work on porous surface
13. Consists of iron powder and pigment
A magnetic wand with soft plastic surface
is used to pickup the powder and applied
The iron filling is then rubbed on surface
to deposit the pigment to develop fingerprint.
Advantages
Easy to clean
Can be used on both porous and non-porous surfaces.
Disadvantages
Less effective on metal surfaces
Video Animation
14. • Consists of metal flakes of1-50μm
diameter and 0.5 μm thickness.
• Used on non-porous surface like glass,
metallic, highly-varnished surfaces, hard
rubber, safes, blue-steel guns or
dark-colored surfaces.
• Applied by fine fiber glass brush
Fingerprints on car surface
15. • First used in 1959 for forensics.
• Ninhydrin is used on porous surfaces like paper and wall.
• It reacts with free amines of lysine residue in proteins
sloughed off in fingerprints
• Produces deep blue or purple color known as
Ruhemann's purple.
• White solid, soluble in ethanol and acetone.
16. • Applied by spraying or dipping.
• Development is done in highly humid environment. Because
water is necessary for this reaction.
• Stored in dark place to avoid degradation.
Disadvantages
• Development need long time without humidity
• Storage is difficult because it is degraded after sometime
17.
18. • Based on the interaction between lipids and fatty acids of sweat residue
with colloidal silver particles, silver has affinity for them.
• Used for developing prints on wet surfaces because Organic residues
are insoluble in water so the physical developer can detect latent
impressions
• Produce dark gray or black impression
• Used on porous surfaces
• Used when ninhydrin and iodine fail to work
• 4 solutions
1. Maleic acid
2. Redox sol (ferrous nitrate)
3. Detergent
4. Silver nitrate sol. Fingerprints on cardboard
19. 1. Pre acidic wash in maleic acid to remove alkaline
reagents.
2. Dip and agitate in working sol. made of ferrous nitrate,
citric acid, detergent, silver nitrate.
3. Place the sample under running water
Disadvantages
• Time-consuming
• Expensive
• Destructive
• Short shelf life.
20. • Used to enhance bloody prints or detect them in blood
• It interacts with proteins in blood and give black
impression
• Can be used on both porous and non-porous surfaces,
skin of corpses
• Used by mixing with methanol or water.
• Rinse the excess dye with distilled
water.
21. • Principle: natural body fats and oils in sebaceous
material of a latent print temporarily absorb the iodine
vapors. This results in a change in color, from clear to a
dark brown, until the effect fades with time
• Iodine fuming is used to reveal prints on porous and
semiporous surfaces such as paper, cardboard, and
unfinished wood but not on metallic surfaces
• One of earliest methods
• Inexpensive and easy
• Non-destructive process - other techniques can be used
afterwards
22. • Iodine crystals are placed
in the ceramic or glass
dish
• Specimen to be
processed is placed in the
fuming chamber
• Gently heating the
crystals causes them to
sublime
• The violet iodine vapor
adheres selectively to
fingerprint residues,
turning them orange
• photographed
immediately
23. • In the lab, iodine
fuming is done in a
chamber
• On the Crime scene,
Fuming wands or
fuming guns are used
• These are simple
tubes with a small
reservoir for iodine
crystals.
• The reservoir is
heated and iodine
vapor is expelled from
other end of the tube
Fuming chamber
iodine fuming gun
24. • Semi-permanent by
treating them with a
starch solution, which
turns the orange stains
blue-black (persist for
weeks to months)
• Benzoflavone is another
after-treatment for
iodine-developed prints.
Prints treated with
benzoflavone are
effectively permanently
fixed with a dark blue
color. Iodine developed
prints fixed with
Benzoflavone (right
Starch treatment
25. • Also called Super Glue Fuming
• Latent fingerprint development ability of cyanoacrylate
discovered in late 1970s.
• One of the most frequently-used latent print development
processes.
• Used on virtually all nonporous surfaces, including glass,
metal, coated papers, and all forms of plastics
26. • Principle: the vapors of cyanoacrylate are selectively
attracted to fingerprint residues, where it builds up as a
crystalline white deposit that can be photographed, or copied
onto tape strips.
1. Fumes of Cyanoacrylate (CA) ester monomers are
introduced to latent fingerprints and quickly bind with
initiators (amines and carboxylic groups) in the residue.
2. The monomer on the fingerprint residue reacts with another
CA monomer in the vapor phase to form a dimer on the
print. This reacts with another monomer, and another,
eventually forming a polymer.
3. The final phase is when the polymer chain reaction is
terminated.
27. Int = Initiator of polymerization. Amines and carboxylic groups in
latent print are the primary initiators of Cyanoacrylate polymerization
28. • The object is placed in an
enclosed chamber containing a
small electric heater.
• A small tray made from aluminum
foil is placed on heater
• When it becomes hot, few mL of
cyanoacrylate are added and
fuming begins
• Fuming is continued until latent
prints develop (30s to 15 mins )
• Can be photographed directly or
treated with dyes to increase the
visibility and contrast of the prints .
29. Advantages
• Effective on rough surfaces
• Vapors are extremely sensitive to fingerprint residue
• Developed impressions are more durable
• Adaptable to many different crime scene and laboratory
situations
• Relatively cheap
Limitations
• Liquid CA and its fumes can cause acute damage to
skin, eyes, and mucous membranes
• The accumulation of CA fumes on parts of a firearm
could have an unfavorable effect during a subsequent
firearms examination
30. • VMD is a long-established industrial technique for the
application of metal coatings to components such as
glass to form a mirror.
• 1968, French workers reported that VMD of a mixture of
zinc, antimony, and copper powder was capable of
developing latent prints on paper.
• Gold and zinc combination used nowadays
• VMD was found to give excellent results on nonporous
substrates
31. • Plastic bags and
packaging
• Glass and plastic
bottles
• Firearms.
• Glossy card,
photographic paper, and
magazine covers
• Clean leather items
(including handbags
and shoes).
• Adhesive tapes (non-
sticky side). Typical vacuum metal
deposition equipment.
32. • The questioned surface is placed in a chamber from
which the air is evacuated.
• The chamber also contains small pieces of gold and zinc
that can be heated electrically to vaporize.
• Zinc cannot deposit on the oily residues present in the
fingerprint but gold can deposit on the entire surface.
• Gold absorbed into the oil containing ridges of the
fingerprint thus there will be no gold on the surface of the
ridges.
33. • Next, Zinc is
vaporized and will
deposit on the
substance where Gold
is present on the
surface i.e. on the
background but not on
the fingerprint ridges.
• The area where zinc
is not deposited will
be the fingerprint Photograph of print
developed on Plastic bag by
34. Advantages
• Can develop marks on substrates exposed to water and
conditions of high humidity.
• Can safely develop latent prints on firearms
• Outperforms all other techniques in developing prints on
plastic bags
Limitations
• Effectiveness can be reduced by the presence of body
fluids and drug residues.
• Difficult to develop prints on heavily plasticized polymers.
• Requires expensive equipment and materials.
35. • Used as early as 1891 for developing latent prints on porous
surfaces.
• Useful on paper, cardboard, plastics and unvarnished, light-
colored woods
Principle: The silver ions react with the chloride ions in salt
contained in the latent print residue to form silver chloride
(AgCl), an insoluble salt which turns grey-black when exposed
to light
AgNO3 treatment effective because:
• The reaction to form the insoluble AgCl is quicker than the
ability of the aqueous carrier to dissolve away the soluble
NaCl
• Insoluble AgCl gets trapped within the structure.
36. • Under room light, the AgCl gradually converts by photo-
reduction to elemental silver of dark grey-black
• Efficient development with 254 nm.
• Silver Nitrate solution uses
1-3% w/v aqueous solution for porous surfaces
3% w/v ethanol-based solution for water repellant
surfaces low absorbency of such surfaces make
developed fingerprints fragile
37. 1. Spraying or immersion
of surface with silver
nitrate solution
2. Rinsed with water after
treatment to remove
excess silver nitrate
3. The treated surface is
exposed to UV light
source which reduces
AgCl to metallic silver,
revealing the prints as
gray-black stains
4. The developed prints
are photographed
immediately and stored
in the dark
39. Limitations
• In prints older than 1 week,
resolution will decrease
because chloride ions in the
latent print residue diffuse
over time
• Latent prints developed by
the silver nitrate method on
certain types of glossy paper
will often disappear within
hours
• Used after all other methods
because stains of AgCl
cannot be removed without
destroying the print.
Advantages
• Since sodium chloride is
not volatile, very old latent
fingerprints retain it and
can be developed by
silver nitrate so this can
work when other
development methods
have failed
41. • Latent print development by Brian Yamashita and Mike
French
• Robert Ramotowski (2013). Evolution of latent print
development techniques.
• Processing guide for developing latent print, FBI, USA
Types of Prints
Fingerprints found at crime scenes or developed in the
laboratory are categorized by some examiners as patent,
latent, or plastic impressions (Lee and Gaennslen, 2001,
p 106), although all three types are routinely associated
with the term latent print.
A patent print is simply a visible print. Many of these types
of prints are wholly visible to the unaided eye, and only
some form of imaging is needed for preservation. A good
example of a patent print would be a greasy impression left
on a windowpane. Patent prints can also be left in blood,
paint, ink, mud, or dust. Lighting is a very important consideration
in the search for this type of fingerprint; a good
There are two distinct types: eccrine glands open by a duct directly onto the skin surface; apocrine glands usually develop in association with hair follicles and open into them.Sebaceous glands secretes lubricating oil. The other sudoriferous gland present in skin is the apocrine
gland. These sweat glands are associated with the coarse
hair of the armpits and pubic area. They are larger than
eccrine glands and secrete a thicker fluid (Anderson et al.,
1998, p 1561). The gland’s duct typically empties into a hair
follicle (above where a sebaceous gland duct would be)
before the secretions reach the skin’s surface (Robertshaw,
1991). Because the contents of the apocrine gland often
mix with sebaceous secretions prior to reaching the skin’s
surface, it is difficult to obtain uncontaminated “pure”
apocrine secretions for analysis.
Early practitioners used a variety of locally
available ingredients to make their own dusting powders. Pigment offering contrast
and definition against the background surface
Some pigment powders offer enough adhesion to be used individually.
Fluffy brushes enables particles to be easily picked up or
“loaded” onto the brush filaments. The low density of this
powder also allows it to easily become airborne during the
dusting process, making a dust mask or respirator necessary
at the crime scene.
To spread it evenly
Ninhydrin (2,2-dihydroxyindane-1,3-dione
amino acids are always present in perspiration in some amount (Speaks, 1970, pp 14–17). On contact with paper, these amino acids impregnate the surface of the paper, where they are retained by their high affinity for cellulose (Champod et al., 2004,). Amino acids do not migrate. These qualities have been exploited to produce clear, sharp images of fingerprints that were up to 40 years old (Champod et al., 2004, p 114).
Used on newspapers as well
Alkaline reagents react with PD strongly
Orange prints are not permanent. Non destructive techniqueand used first.
Heated by a battery operated mechanism
giving substantial advantages over techniques such as Cyanoacrylate fuming
plasticized polymers (such as clingfilm and plasticized vinyl)
its use is limited to well-equipped and well-funded forensics labs.
(waxed paper, cardboard with wax finish, and Styrofoam)