Crime Scene Investigation!!

Sadly, three crimes were committed on the night of November 30th in the very room of our earth/bio class. Our forensics team was divided up into three major groups of seven to discover the truth of what had occurred that night. We had the third crime scene: a residence that was broken into.

A residence was broken into the night of November 30th. Although no bodies were found at the scene, there are enough evidence to point to the victim and its attacker.

This is the untampered crime scene.

There is a

• footprint
• two ripped up notes
• hair sample
• a fiber
• a high heel
• a pair of earrings
• possible poison
• a fingerprint to lift

There are ten possible suspects and two animals that may have been present at the scene.

We all worked with different part of the investigation. I took over the hair and fiber with Vicki. The hair was very short and multicolored, and after examining it closely under the microscope we determined for it to be the dog, Tyler's hair. The fiber was a ripped piece of green nylon.

We didn't have the chance to conduct a blood analysis test, so on the notecard it told us that the person who shed the blood had type A+. We narrowed down the suspects to the following people:

• Tyrese Jefferson
• Jeb Sampson
• Sandra O'Connor(whose bloodtype was not listed
• Courtney Smith
• Jet Trong (Also unlisted)

The other teammembers put the note back together and one of them read "You will never find her!" and the other read "Please help me". It can be deducted that the culprit had written the first note and the victim the second.

The note asking for help had matched Tyese Jefferson's handwriting found on her profile.

We concluded that because of a few qualities found in her handwriting such as

• the capital letter has more spacing in between the next letter than the others
• her y's are lavishing, which may mean that the letter h may have the same effect
• her letter 'n' is not detailed, having the pencil draw an arch instead of a proper 'n'

The second note is most likely to have been written by Smokey Johnson.

Not many of the letters on his profile match those on the notecard, but there is one definite feature and that is the letter "e". The notecard and Smokey Johnson both has the rounded "e" that others don't have. The letter "n" was also a deciding point because his spacing between the line of the "n" and the arch was far apart.

Furthermore, the two sets of fingerprints left at the scene matched the two people.

This is a plain whorl, the quality only found in Smokey Johnson's fingerprint.

The ulnar loop is only apparent in Sandra O'Connor and Tyese Jefferson's prints.

From the handwriting analysis is it most likely Tyese's print.

Lastly, the possible poison was tested to be iodine.

There were a few extra information we had gathered:

• High Heel
• Size 8
• The shoe straps with a belt, meaning that it'll be difficult for it to just fall off.
• Gold Earring
• The post is bent, which means that it could be uncomfortable and unnatural to have it in your ear.
• Skateboard shoe
• Men's size seven

Now we knew the truth behind what had occured that night.

Smokey Johnson Nov. 30 9PM

This is it. This is the night I will finally get revenge on my beloved Tyese. I'm upset it has to be like this. You brought this on yourself Tyese, remember that...

A few months back, Smokey attended a certain counseling class after punching his co-worker at work. In that one session he fell in love with his counselor, Tyese Jefferson who had faced him with true kindness. That was the day he started stalking Tyese and observing her, catching her every minute of every day. He thought that she was the one. Until the day a restraining order had been held against him by his true love, Tyese. He couldn't believe that the woman he loved had eliminated him from her life. So he planned revenge, to get back at her for her wrong-doing. He stopped in front of a house too familiar to him, more familiar than his own. Walked around to the back where he had usually observed Tyese from and snuck inside by the window, leaving a distinct footprint underneath...

Tyese Jefferson November 30th

"Ow ow ow.. what is wrong with this earring!"

Tyese was walking home from a party, all dressed up for the occasion but not having as much fun as she was expecting to have. It may be stress from work, stress from fear... she promised herself that as a professional she would not live in fear of that man. What she needed was to get some rest and to take off the stupid earring. She had accidentally stepped on it this morning but couldn't leave them behind because it matched her dress completely. She wore a green nylon cardigan over the dress because it was almost December and cold enough she could see her breath stay in the air. Her high heels were clanking against the cement as she walked in the quiet street. She stopped to pet Tyson, the friendly neighborhood dog that she loved. After a few minutes, she went on to return to her home.

As soon as she turned the key and stepped in the door, Tyese took off her earring. The relief from its removal swept through her entire body, the tensity escaping from her pierced ear. She undid the belt loop of her high heel and went on to remove the other when she heard a noise that was not from outside, but from inside her home. The tensity returned, and she looked up to see her utmost fear approaching her. Tyese thought to run outside but with one three inch heel and the other barefoot, she realized it was a futile attempt. Instead she scribbled a note saying "Someone please help me!" and then was grabbed by the man. Through the struggle, her favorite cardigan was ripped and her hands and legs were bound together with no promise of escape. She watched him as he scribbled down a note on the counter. She couldn't see what it said, but knew that it was not good.

Smokey Johnson- November 30th

"You will never find her!" After finishing the note, he went into the bathroom. Not to "do his business" of course, but to look at the iodine bottle and wonder what to do with it. From his observation(stalking) he knew that without this to regulate her Thyroid problem, it could cause Tyese a lot of suffering and possible death. He was seeking for revenge, it would be perfect. He smiled, left the bathroom empty handed and proceeded on relocating Tyese to a secluded place until her slow, horrible death.

The job for the forensics team was over. It was up to the police to find Tyese, dead or alive. The only thing we could do was to hope that she was still safe.

Labs

We conducted a few extra mini-labs that relate back to our current studies in forensics and criminal studies.

Witness Account Lab

In this lab, I worked with my usual group to cut faces out from magazine. Of course it was more than just that. Our assignment was to cut out the faces with similar sizes, cut out the prominent features (i.e. hair, nose, mouth, etc) and mix them all up in a pile. I picked a blonde lady on the cover of a magazine.  

She was very pretty until I cut her face into pieces. We all had people with different distinguishing points: a young blonde, a middle-age blonde person with short hair, a hispanic woman, and an African American woman. After having the person sitting next to ourselves look at the magazine model's profile for ten seconds, we mixed it up in the middle and had that person remake the models. I gave mine to Audrey, and she did it perfectly.

So yes, she would make a great witness. Our group got every person right perfectly, although it may have resulted from the different ethnicity of the profiles we chose.

Footprint Lab

In this lab, we analyzed each other's footprints in a tub of dirt prepared in class. We looked at the size, shape, pattern, and other distinguishing points of the print. This is my footprint below.

It was approximately 24cm in length and the widest part was 10cm.

I was wearing a sandal with the guess print running across the back, but it was too faint

for it to show up in the footprint. In the dirt, the print looked completely flat with no patterns.

The gender is hard to tell from just the footprint, because it can be a young boy or a girl.

The height chart based on foot size said that I was from 5'1 to 5'3 range. I'm a little below that

but I guess it could mean that I would still grow!!

This is Travis's footprint, and it was a lot different from the rest of ours because he

was the only guy in our group of four. It was 31 cm long and 12.5 cm wide. He was also

the only one wearing sneakers and as you can see there were distinguishing patterns

on the sole of the shoe. The brand name couldn't be seen in the print, and from the height chart,

he was assumed to be around 6'1 to 6'5, which is true. The gender is most likely to be male, although

it's never foolproof considering there are a few extremely tall women.

This is Jessica's footprint. The most distinguishing feature, as you can probably tell, is the

many dimples left on the print. The shoe size was 24 cm long and 8 cm wide. It is most likely

to be female because her shoes were the kind that is sold only to women.

Finally, this is Audrey's footprint and like me, she was wearing a pair of flipflops.

This can be recognized because both our prints were completely flat with no pattern

at all. The footprint was 27cm long and 10 cm wide. The gender also couldn't

be distinguished from this print, the height is thought to range from 5'5" and above.

Create a Profile Lab

This mini-lab is the smaller scale of the criminal investigation lab we did later on in class. Each group had five evidence to go off of to create a model of what the criminal may look like. In our group there was a lip print/blood, a ripped up note, two hair samples, and fingerprints. From these evidences we were to portray the criminal's features. We came up with an African American woman from the hair sample and the smeared lip gloss, the fingerprints couldn't tell us anything because we had nothing to compare it to, same thing occurring with the handwriting analysis. These need to be conducted after the suspects had been narrowed down because it is almost impossible to go through all the handwritings of everyone in the world.

Lip Print Lab

In this lab, all members of the class (including men) put on lip gloss and then left an imprint of their lip on a piece of notecard. We then identified five qualities about our individual lips, put them all in the middle and then had an individual sheet where once again, we left our lip print. Then we did a carousel where another group tried to match the prints by the qualities on the notecard. I used a coral color and it didn't show up very well. In the mark, my upper lip was a lot rounder than my bottom lip, there were a little space in between the lips, the lips were a regular curve on both sides without distinguishing features, and it was length was smaller than others. The group that identified ours got it 100 percent. We identified a group of six, the largest group in the class and only identified half of them correctly. There was a reason behind this, and that was because three of the six lip prints were completely messy and looked like it was rubbed against the paper so that the prints were indistinguishable. These cases, however, are often seen in real situations so it still added a piece to our knowledge that lip prints can be tampered with.

Poison Lab

poison- substances that can cause disturbance to organisms, usually by chemical reaction when sufficient quntity is absorbed by an organism.

Poisoning can result from bites, medicines, plants, lead, food poisoning, allergy, and lack of regulation by medicine.

Its symptoms are the enlarged pupils, color change of skin, drooling, and bleeding for corpses. If the individual is alive, they could show an increase in breathing rate and heartrate and nausea.

In this lab, we obtained a few samples per station to test for the presence of a possible poison.

Station 1

1. lead- because it reacted with KSCN by turning blood red
2. iron- because it turned neon yellow with the presence of Pottasium Iodide
3. cromium- because it turned orange with the presence of acid

Station 2- testing for sugar (poison for diabetics)

1. Negative
2. Negative          none of the three turned purple
3. Negative

Station 3- ammonia (odor, pH above 7, PHth turns it purple)

1. positive- ammonia
2. negative

We conducted three more similar stations using cyanide, asprine, and iodine.


Drug Lab
In this lab, we investigated three drugs: cocaine, metamphetamine, and LSD. We used SIMULATION drugs that had the same qualities as the listed drugs, but lacking the ability to make people "happy". We tested six possible drugs where the cocaine reagent turned it blue, and LSD turned it yellow. We couldn't obtain fake meth so we only performed these two tests. The second and the fourth were cocaine, the sixth was LSD and the rest were probably meth from the process of elimination.

Cocaine
1. Chemical Name: Benzoylmethylacgoine
2. .Chemical Formula: C₁₇H₂₁NO4
3.   pH: 4.5

LSD
1.  Chemical Name:  Lysergic acid diethylamide

2. Chemical Formula: C₂₀H₂₅N₃O

3. pH: 4

We had to dissolve the possible "drug" particles in thewater before usage. This needs to be conducted to test solid drugs.

This was the reaction seen in the fourth lab, where the cocaine reagent turned blue, LSD reagent was negative because it was red instead of yellow, and at the pH of 8. 

Drug testings may become important in criminal investigations to observe if an individual involved in the case was emotionally 'unstable' by the usage of illegal drugs.

handwriting analysis

History of Handwriting Analysis:

Aristotle first noticed the correlation between personality and handwriting over 2000 years ago. However, the field of graphology wasn't closely examined until the 1600s. In 1622, an Italian professor of philosophy at a university published  a book on the analysis of handwriting and its character. Then the subject was left for over two centuries, being reexamined once again in 1830 by Abba Michon. He became a headmaster of a school in the late 1800s and wrote a few books on graphology. Alfred Binet called the subject "the science of the future" despite the graphologist's rejection of his research. After World War II, the interest in graphology extended to the rest of the world such as Germany. Max Pulver, a Swiss scientist, was the first to try to 'interpret' graphology in the means of psychological analysis, called psychoanalysis for short. This was soon followed by Ania Teillard who applied his knowledge of typological theories to this study.

Twelve Characteristics of Handwriting

1. Line quality - free flowing, shaky, or wavering = speed
2. Spacing of words and letters- Is the spacing consistent?
3. Ratio of the relative height, width, and size- Is the ratio consistent?
4. Pen lifts and separations- Does the person stop to form new letters and begin words?
5. Connecting strokes- Are capitals connected to lowercase letters and are there connecting strokes between letters and words?
6. Beginning and ending strokes- straight or curled, long or short, upstroke or downstroke
7. Unusual letter formation- any unsusual letterings?
8. Shading or pen pressure- pressure on upstroke or downstroke?
9. Slant- left or right, up and down, consistency?
10. Baseline habits- the writing above or below a line?
11. Flourishes and embellishments- If there are any, what are they?
12. Diacritic placement- the crossing of the t's and the dots on the letters

Indicators of Forgery

1. Blunt starts and stops- the writing doesn't flourish at the end and has blunt ink endings
2. Pen lifts and hesitation- gap and overlapping of lines, occasional pen stops in midwriting
3. Tremor- the pen is moved so slowly when forging that it's not a smooth line
4. Speed and pressure- the pen is moved so slowly that the thickness of the line stays consistent because of the constant pressure placed on it
5. Patching- fixed errors in the writing, obvious difference in signature

Types of Forgery

• Normal Hand Forgery
• When the writer doesn't have a model to go off by, and simply writes the indvidual's name 
• Free Hand Forgery
• The writer simulates the signature of the individual by looking off of their true signature. These have a slow, 'drawn' look. matter how well the forgery is written, the ratios of letters and its proportions will not be the same. Even if the forgery is detected, the forger is almost never traced back to.
• Tracing
• transmitted light
• when the genuine signature is placed underneath the paper where it's being forged on, and then held up to a light source (such as a window) and traced
• carbon intermediate
• is used when the object is a thicker object than paper that cannot be traced in the light. The carbon paper is placed on the place where the signature is being forced, and over the carbon paper the original signature is placed. The original signature is then to be traced by a writing utensil and leave a carbon imprint on the object. The carbon can be then traced over once again to create a forged signature.
• pressure indented image
• The original copy of the signature is traced by pen over the paper to leave an imprint, and then traced once again working almost the same way as carbon tracing. This presents a problem because if the forger tries to make it look natural a few characteristics may be missed, but tracing every single part will make it slow and blunt.
• transferred forgery
• If the original signature is written by a ball point pen using ethylene glycol medium (carries dyes and such) then that signature can be lifted by wax paper. The wax paper can then be placed on the paper to be forged on, and then rubbed the ink melts on to the actual paper.

Konrad Kujau's Hitler Diaries...In April 1983 an announcement was made in Germany that 62 handwritten secret diaries of Adolf Hitler had been discovered which was thought to turn out to be one of the most priceless writings ever to be discovered. These were supposedly discovered a few years earlier when an East German came in posession of them after they were recovered from a fallen Nazi plane. The pilot, Lt. General Hans Baur claimed that the plane carried Hitler's archives and it is believable that these are genuine artifact. Some doubt were expressed by the magazine, Stern, in case that it was not authentic and the potential of selling false information to the public.They sent it through graphology experts and it was proven to be a true match. Although the company was ecstatic by this news, some researchers were puzzled by the more 'kind-hearted' nature of Hitler that was presented in this diary, contradicting his public image. After rigorous testing, it was proven that these diaries were indeed forgeries, and the original copy they had based the original testing off of was also forged by the same individuals.  The forger was Konrad Kujau, a Hitler enthusiast who was later remembered and recorded in history as the most notorious, elaborate forger of all.

Handwriting Lab

In this lab, we forged each other's handwritings by free hand and tracing.  Starr observed my handwriting and said that there are no connection of letters, and the y's and the g's are circular and embellished.

I think she did a great job, the traced one look a lot closer to the original but the letters are darkened and blunt making it seem unnatural.

Hair/Fiber Analysis

HISTORY
Hair:

The first theory of trichology (study of hair) was published in 1857 and introduced the possibility of classifying a person from their hair. However, the microscopic hair examination only became possible in the twentieth century.

In 1857, the beginning of the recognition of trichology was incited by a trichology report published in France  but the field itseld didn't grow until the twentieth century. In 1931, Professor John Glaister published "Hairs of Mammalia from the Medico-legal Aspect" established a reference foundation in this area of study, eventually followed by "Microscopy of Hairs: A Practical Guide and Manual" by John Hick, which described the possible use of hair examination in the work of forensics. The analysis of hair can narrow down the person's race, gender, hair color, etc.

Fiber

Fibers are considered "trace evidence" and although it doesn't have as much effect in narrowing down the culprit as hair will, it can be helpful if the  fabric has unique patterns or unique fiber. Traces of fiber is frequently left in the crime scenes, either from the clothes that the culprit had worn, or more likely, the traces of the victim being at certain places before death. 

 PICTURE AND LABELED PART OF COMPLETE HAIR

Layers:

The layers of hair can be grouped in three distinct layers; cuticle, cortex, and medulla.

Cuticle

• is the outer layer of the hair shaft
• looks like scales of a fish, cells overlap one another
• provides protection, flexibility, strength, and sheen

(picture of healthy cuticle)

Cortex

• lies below the cuticle
• the hair color is determined here by the melanocytes which consume melanin
• made of keranin protein
• most of the volume of hair

Medulla

• core of the hair
• 10% of volume
• may be absent in thin hair

Parts of Hair

Shaft

• Visible part of hair above scalp

Root and Bulb

• living portion of hair delved into the scalp
• Bulb controls the growth of hair

Papilla

• Empty area at base of bulb
• Nourishment is given to the hair from here

MAJOR TYPES OF FIBERS

• Cotton
• soft and absorbent
• short, fine and creamy white color(unless colored otherwise)

Hair/Fiber Lab work : (My drawing of cotton fiber under microscope)

Color: white and transparent

Features: single threads are spread everwhere, all are very thin and loosely packed

• Nylon
• very durable and can be used as seatbelts, tires, etc.
• high resistance
• stretches

Lab observation of Nylon

Color: black
Condition: frayed
Observation: webbed into a consistent pattern that seems to be hard to break
• Linen
• High absorbency
• good conductor of heat
• high luster
• Polyester
• low absorbency
• resist wrinkling
• durable
• Silk
• sensitive to dyes
• soft texture
• luminous

Lab work: Silk observation

Color: Gray

Observation: weaved simply, but frays at the end

• Wool
• Fire resistant
• Water absorbent
• Durable
• Sensitive to dye

Lab work: Wool Observation

Color: black

Tip: Separates

Features: No observable pattern, shaggy and separates into many directions; closely packed





Hair/Fiber Collection Technique

Hair:
1. Recover all hair samples from the scene with a pair of tweezers and store them in labelled envelopes.
2. Store the envelope into an even bigger bag to not lose these important evidences.
3.  If the hair is attached to things such as dried blood or glass, do not remove it but collect the entire thing.

Fiber:
1. Pick up the fiber and seal them in an envelope so that it won't go missing.
2. If the fiber is too small, tape the fiber sample so that they won't escape from cracks in the envelope.

Typical Hair/Fiber Analysis
A prediction can easily be made of the characteristics of the person by their hair by simply holding it under a microscope. Each race has their distinguishing feature of hair, and although they rarely match perfectly, if the features are the same then it is probably a safe prediction.

For example, in our lab we examined not only fibers but also strands of hair from different people.

Colored Hair

Color: brown or yellowish

Condition of tip: Cut, sharply diagonal

Observation: smooth, but the color is lighter in the middle.

The middle part of hair forms a webby pattern.

Asian Hair

Color: black

Condition of tip: flat and cut

Observation: smooth, lighter in the middle but almost solid color

African American Boy Hair

Color: black

Condition of Tip: rounded, brown

Features: The stem is thin, but the tip rounds and becomes thicker

Synthetic Hair

Color: brown

Condition of tip: rounded a little bit

Features: lighter in the middle but not by much, smooth and straight

We also looked at hairs that belonged to non-human beings.

Dog Hair

Color: gray and black

Condition of Tip: Cut

Observations: rough edges, light at someparts, webby at the

lighter spots and overall thicker than human hair

Cat Hair

Color: black

Condition of Tip: pointy

Observation: wihite in the middle and eventually flattens out, webby

If the researcher wishes to gain more foolproof data from these samples, a DNA test can also be conducted. The individual's hair can be used as evidence for the usage of illegal drugs. Although trace evidences aren't as reliable as blood analysis or fingerprints, it can be combined with other information to pose as evidence. The individual's health condition can also be identified by the presense of mercury in the hair.

Reliability of Hair/Fiber Crime Scene Data
The reliability of hair varies, and the miscalculation is likely to occur from colored hair, perms, etc. There are methods to de-contaminate the hair sample, but it only makes the image clearer, not having much effect on finding the true color of the hair, eventually leading to their race. The chemicals overlapping the hair shaft makes it challenging to use the hair as a reliable evidence. Consistency is not present in these tests. The numbers for the "age range" of the person also vary by the lab itself, because no national reference table is made to determine the person's age depending on the amount of mineral in one's hair.

Notable Case
In 1936, the wife of a NBC executive was found strangled with her pajama top in the bathroom of her home. The scene indicated that she had known her killer, and from lack of evidence a professional was brought in to examine the scene and collect evidence that may have been missed. There was only one evidence that was found, and it was a strand of white hair later tested as being horse hair. That day two furniture movers had delivered a horse haired couch and it was predicted that one of these two had paid her an early visit. The store was quickly identified for the couch's distinguishing features and the two men were interrogated til one of them had confessed to the murder. This was one of the first cases where hair analysis was used to convict a criminal.

http://www.ehow.com/about_6102496_forensic-science_-hair-fiber-analysis.html

http://www.lamasbeauty.com/beauty/articles/correa/what_is_hair.htm

http://www.maquillagemaven.com/2011/05/anatomy-of-hair.html

http://www.textilefurnishings.com/polyester-fabric.html
http://www.crime-scene-investigator.net/collect.html

Fingerprinting

HISTORY

Fingerprinting was first recorded in ancient Babylon around 1000-2000BC. The Babylonians used the method of fingerprinting as means of business transactions, by pressing their finger into a clay tablet. The Chinese had also used clay seals to identify their lost children, or to 'sign' documents around 3rd century B.C.

--(Clay fingerprint mold found in China)

After many centuries, a government official in Persia had discovered in the 14th century that no two fingerprints were the same and that all prints formed a unique pattern.These were then given names for its distinguishing features by an Italian professor Marcello Malpighi, who inspected the prints by the microscope that was still a relatively new invention in this time period. He noticed ridges, loops, and spirals in the prints and in respect, a layer of skin was named after him called “Malpighi layer”.

 In 1823, an anatomy professor John Purkinje published a thesis after furthering Malphighi’s studies of finding nine possible patterns of a fingerprint. However, this document was not recognized as a method of identification of people but as mere factual evidence. Forty years later Professor Paul-Jean Coulier published a finding on a preservation method of prints and also the potential for further identification of criminals by using a magnifying glass to examine their fingerprints. Dr. Henry Faulds applied printers ink to retrieve fingerprints and was the first to be able to identify them.

Mark Twaine, a notable author and also the creater of Tom Sawyer, introduced identification of the murderer by his fingerprint in the novel Life on the Mississippi and influenced the others to wonder if gathering fingerprints at the crime scene would lead to a successful arrest. Juan Vucentic first used this new idea to use and convicted Francis Rojas by the residue of her bloody fingerprint to the one that they had filed. Afterwards Sir Francis Galton published a book, Fingerprints, to provide a classification system for the fingerprints and to prove the permanence of the fingerprint by observing fingerprints while aging. He also solidified the uniqueness of each fingerprint and according to his research the odds of two people having the same fingerprint were 1 in 64 billion. India was the first to recognize this as a method to identify an individual and created a database of all the criminals' fingerprints, the most recognized being Calcutta Anthroprometric Bureau in 1897. Azizi Haque and Hem Chandra Bose developed the Henry classification system (named after their supervisor) to file the fingerprints.

In 1901, New Scotland Yard established a Fingerprint Branch following India's example, and also employed the Henry System of Fingerprint Classification. Three years later, the New York State Prison gathered the fingerprints of criminals and expanded throughout the country. International Association of Chiefs of Police (IACP) formed the National Bureau of Criminal Identification strictly for fingerprint identification.

Example of a fingerprint card used

Congress formed the Identification Division in FBI, and the criminal identification of IACP and Bureau of Criminal Identification were consolidated into one database. By 1987, this database grew into 200 million manually filed fingerprint cards. Automated fingerprint identification system was later developed and the 200 million cards were computerized. It was still not as effective as the programs of today because many of the datas were duplicated and there were glitches in the system.

TYPES OF FINGERPRINTS

The types of fingerprints can be distinguished in three broad groups;

Visible

• Also called patent prints
• left with a medium such as blood, ink, dirt, grease, etc.
• can be seen by human eyes

Latent

• Not seen by the naked eye
• formed from the sweat (or fluid contained in sweat) on the body  
• must be developed before they can be seen or photographed
• can be made visible by dusting, fuming or chemical reagents

Impressed

• also called plastic prints
• indentations left in soft surfaces, such as clay, wax, paint, etc.
•  can be viewed without development

DEVELOPING PRINTS ON SURFACES

There are four primary chemicals used in basic development of fingerprints. Those are

• iodine
• cyanoacrylate (super glue)
• silver nitrate
• ninhydrin

Some of the minor chemicals also used are listed below

• diazafluoren 1 (DFO-1)
• rhodamine
• ardrox
• sudan black
• thenoyl europium chelate (TEC)
• acid fushin

Porous-
 paper, unfinished wood, cardboard... can easily preserve because the latent print can soak into a surface

Non-absorbent
plastic, glass, metal.... fragile evidence and can be easily ruined or wiped away

Hard surface
asphalt, concrete- difficult to collect fingerprint from because it is not completely smooth, and the print is likely to be disfigured

Smooth surface
Smooth surface such as glass, wood, plastic, etc in which fingerprints can be easily lifted from.
Methods to Develop
Cyanoacrylate is used to 'fume' fingerprints onto the surface. To do this, the smooth surface with fingerprint needs to be contained in a jar with a couple drops of cyanoacrylate in it. After about five minutes, the print would've developed on the microscopic slide and you have your evidence! Iodine goes through the same procedures, with the fuming method.

Silver Nitrate reacts with the sweat contained in the fingerprint and it should be sprayed onto the print after being diluted by water or alcohol.

Ninhydrin also reacts with amino acid (sweat) but the prints will come up in purple, and take about 24 hours for it to develop after the prints are sprayed with a generous amount of Ninhydrin.

 

BASIC SHAPES/PATTERNS OF FINGERPRINTS

The patterns of fingerprints can be categorized into three types: arches, loops, and whorls.

Fingerprints can be distinguished by its unique patterns. Although fingerprints differ for each individual person, every human being has one of nine patterns established by Purkinje on their print. The nine patterns are condensed into three main patterns: archs, whorls, and loops.

The Arch

About five percent of the fingerprints are archs, one of either plain arch or tented arch. In an arch, the ridges of the print lies on top of one another forming a semicircle pattern on the surface. There are typically no deltas found within this pattern. There are two types of archs: plain arch and tented arch.

Plain Arch- even flow of ridges       

Tented Arch- makes a triangle shape within the ridges

Note: within the tented arch there can be radial and ulnar
radial- points to the right
ulnar- points to the left








The Loops
Loops occur in 60 to 70 percent of all fingerprints. In a loop pattern, the lines start from one side of the finger and revert back in the direction they started from. There are specifically two types, radial and ulnar.

Radial Loop and Ulnar Loop

Radial loop receives its name from the radius bone in the arm, and that is a good way to remember. Ulnar loop receives its name from the ulna. The ulnar loop always starts on the outerside of the hand, at the pinky, and the radial loop starts at the inner side of the hand towards the thumb.

Central Pocket Loop

Central pocket loop consists of multiple free curving ridges and two deltas. It almost looks asthough it is a complete circle on your fingerprint.

Twinned Loop (Double loop)

In a twinned loop, the two loops link together to make an 'S' shape on the print. There are two deltas residing in this particular pattern.

The Whorls
The whorls are seen in 25 to 35 percent of all fingerprints. Any fingerprints consisting of two or more ridges are considered a whorl.

Plain Whorl

In a plain whorl, the deltas make a complete circuit creating a circular print.



Fingerprint Lab

In this lab, we stamped our fingerprints onto a sheet of paper used for criminals to record their prints.

Most of the fingerprints I had were either ulnar loops, or radial loops. No whorls were found in my prints and two arches were found on the right hand.

HOW TO COLLECT/LIFT PRINTS

1. Coat the present fingerprint with powder; talc if on dark surface and granite if on light surface.
2. Brush over the print gently without disturbing it with soft brush made of either camelhair or a regular fiberglass brush.
3. Place the sticky side of a transparent tape on the dusted fingerprint
4. Tape the print onto a contrasting colored paper.

Lifting Fingerprint Lab

Using the above procedures, we conducted an experiment in lab using granite.

To obtain oil to make our fingerprint visible, we rubbed our finger on either the side of the nose or the forehead to obtain natural oil collected on the body.  The granite powder was not fine enough for it to leave a complete print on the tape. A lot of them were little pebbles, interfering with the lifting. The one to the far right was the best out of all, because the pattern was visible.

Bibliography

http://www.odec.ca/projects/2004/fren4j0/public_html/types_prints.htm

http://thumbs.dreamstime.com/thumblarge_409/1244836472mo934k.jpg

http://www.joplinglobeonline.com/blogs/scott_blog/?entry=entry090813-132157

http://www.anilaggrawal.com/ij/vol_002_no_001/papers/paper005.html