Chapter 5,6,7 Flashcards
Talk about Henry Faulds and his syllabic system of classification.
- -a Scottish physician and superintendent of a Tokyo hospital in late 1870s
- -used ink to record prints–he collected thousands of fingerprint cards, compared them against each other to prove individuality…..to prove permanence Faulds and his med students used razors, pumice, etc to remove their friction ridges…..and they grew back
- -published his findings in journal “Nature”
- -he created a syllabic system for classifying prints….each hand was represented by five syllables
What about Sir Francis Galton and the tripartite classification?
–he formulated a system where L was for loop, W for whorl, and A for arch
What about Juan Vucetich and the Argentine System?
- -1891 fingerprints replaced anthropometry….first case of this
- -created a classification system called “dactiloscopia” meaning finger description—his system was published and went worldwide
Sir Edward Henry and the Henry Classification system.
–Henry was a police inspector in India and couldn’t properly identify the native people…..met with Galton…..he devised the Henry System that was so successful in 1897 the British Indian government instituted it as the official method of criminal identification
Talk about AFIS history.
- -early 1960s the FBI, Home Office in the uk, Paris police, and Japanse national police initiated projects to develop automated fingerprint identification systems
- -1974 Rockwell International built 5 production model automated fingerprint readers called Finder…..delivered to FBI and millions of criminal cards were converted
- -company called Morpho Systems (Safran group) out of France designed a system
- -benchmark testing in San Francisco of competing in-use systems….NEC was awarded the contract for their AFIS system in 1983….dramatic increase in latent print convictions in San Fran
- -By the 1990s the four biggest names were Morpho, Cogent, Printrak, and NEC.
Talk about the skin and functions.
- -largest organ in human body—total area more than 2m2
- -regulates body temperature, retains moisture, protection from organisms, sensation, excretion
What are the three primary glands that produce sweat?
- Sudoriferous glands (eccrine and apocrine)
- Sebaceous glands
- -eccrine are most concentrated on friction skin—amino acids in sweat—difficult to tell if any lipids are secreted here
- -apocrine associated with coarse armpit and pubic hair….larger than eccrine glands and secrete thicker fluid….typically empties into a hair follicle….
- -sebaceous glands found in the dermis throughout the body….associated with hair….abundant on scalp, face, anus, nose, mouth, external ear…..not on friction skin
- -sebum comprised mainly of glycerides, fatty acids, and wax esters
What do physical developer and oil red O react with in matrix?
–PD reacts with large water insoluble molecules like proteins, and ORO reacts with non polar lipids like fatty acids
Discuss fingerprint powder, theory.
- -latent print powder likes moisture and clings to print residue…..most commercial powders rely on two essential elements to provide adhesion to latent print residue: pigment and binder
- –pigment provides contrast and definition against the background
- -binder provides for maximum adhesion to residue
Ninhydrin history.
- -mistakenly prepared in 1910 by Siegfried Ruhemann
- -observed it reacted with skin and amino acids….purplish colour
- -not used for forensics until 1954
- -amino acids impregnate the surface of paper where they are retained by their high affinity for cellulose…..because of this the amino acids do not migrate, but the amount of amino acids degrades over time
- -the reaction with amino acids produces the ammonium salt of Ruhemanns purple
1,8-Diazafluoren-9-one.
- -was first prepared in 1950
- -reaction with amino acids was not explored until 1990
- -faint red or pink ridges
- -similar to Ninhydrin, but is more sensitive and produces a greater number of prints
- -the combination of Ninhydrin and DFO produces more prints than either one on their own
1,2-Indanedione.
- -reacts with amino acids, similarly to Ninhydrin
- -faint pink coloured ridges
Cyanoacrylate fuming.
- -super glue first developed in 1950s for aircrafts
- -late 1970s it was discovered that the fumes could develop latent fingerprints
- -CA molecules bond to residue via polymerization to form white strand-like appearance
- -the role of humidity is not understood
Vacuum metal deposition chamber.
- -industrial technique for metal coating mirrors
- -found to give great results on non-porous substrates
- -prints subjected to gold, which are absorbed by lipids in print residue, and adhere to furrows…..then zinc is deposited, and condenses on gold….theory of nucleation
- -effective on wetted items and CA is not…..
Blood enhancement techniques, tests for heme
Blood: consists of red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes)….all are in a fluid called plasma which consists of 50% blood volume….red cells contain hemoglobin protein! and white cells have nucleus with DNA
Amido black: stains protein in blood….great for fingerprint and footwear enhancement…..coomassie blue is another one
Luminol reacts with the heme in the blood..
Hungarian red dyes protein in blood…..has ability to fluoresce
Aqueous Leuco Crystal violet ….popular enhancement technique and presumptive test for presence of blood…..can still use amido black afterwards
Ninhydrin and DFO reacts with amines in blood, and are great for enhancement of blood
Can use high intensity light in uv and violet regions of spectrum for blood to fluoresce
