FREE ESSAY ON FORENSICS

FORENSICS

Forensics is defined as the aplication of science to interpret clues for crime
investigation. The earliest forensic scientists were physicianswho were called upon to
give an opinion as to the cause of death in individuals. Now most of the forensic
scientists are investigators that pick up clues at the crim scene. Because criminals
often are not the brightest people on the planet they often do not plan out a burglary or
theft and carelessly leave behind distict clues that allow an invetigator to track them
relatively easily. There are many areas of forensics which include: general crime scene
investigation, forensic chemestry, forencic toxicology,forensic pathology, genetic
figerprinting, fingerprinting and chromotography.
The purpose of crime scene investigation is to help establish what happened (crime scene
reconstruction) and to identify the responsible person. This is done by carefully
documenting the conditions at a crime scene and recognizing all relevant physical
evidence. The ability to recognize and collect the evidence is important in solving and
prosecuting violent cases. In majority of the cases, The law enforcement officer who
protects and searches the crime scene plays major part in determining whether the
physical evidence will be used in solving or prosecuting the violent crime.
Crime scene investigation is not what we think it is, unlike the movies, is actually a
difficult and time consuming job. There is no substitute for a careful and thoughtful
approach. One should not leap into conclusions as to what happened based on what little
information he has with him or her, but generate several theories of the crime, keeping
the ones that have not been crossed out by incoming information at the scene. Reasonable
inferences about what happened are produced from the scene and appearance and information
from witnesses. These theories will help guide the investigator to document specific
conditions and recognize valuable evidence. 
Documenting crime scene conditions can include immediately recording transient detail
such as lighting (on/off), drapes (open/closed), weather, or furniture moved by medical
teams. Certain evidences such as shoe prints or gunshot residue is fragile and if not
collected immediately can be destroyed or lost. The scope of the investigation also
extends to considerations of arguments which might be generated in this case (self
defense / suicide) and documenting conditions which would support or refute these
arguments. 
In addition, it is important to be able to recognize what should be present at a scene
and what should not (victim's vehicle/wallet) such as objects which appear out of place
(ski mask) which might have been left by the assailant. It is also important to determine
the full extent of a crime scene. A crime scene is not merely the immediate area where
the body is located or where an assailant concentrated his activities but can also
encompass a vehicle and access/escape routes. 
Although there are common items which are frequently collected as (evidence fingerprints,
shoe prints or bloodstains ), literally any object can be used as physical evidence.
Anything which can be used to connect the victim to a suspect or a suspect to a victim or
crime scene is relevant physical evidence. Using the shopping list approach (collecting
all blood stains, hairs, or shoe prints in recognizing the best evidence. For example,
collecting bloodstains under the victim's body can be excellent physical since it can be
directly tied to a matchbook found in a suspect's pocket. 
Since a weapon or burglar tool is easily recognized as significant physical, it is
frequently destroyed by the perpetrator. Sometimes the only remaining evidence is
microscopic evidence consisting of hair fibers, or other small traces the assailant
unknowingly leaves behind or takes with him. Although this evidence is effectively
collected when the clothing of the suspect or victim is taken, protocols (involving tape
lifts ) should be in place to process nude bodies so as to not lose this fragile
evidence. 
Forensic chemistry is the application of chemistry to the investigation of a crime. The
investigation of the crime is , however, is not limited to crime against individuals such
as home suicidal, theft, fraud and arson. Forensic chemists also involved in the
investigations of crime against society such as food adulteration, environmental
pollution, use and pollution of unsafe chemicals and dangerous working conditions.
The application of chemistry to the study of physical or theoretical problems, the
results of which may be entered into court as technical evidence. Boundaries are not
sharply defined for forensic chemistry, and it includes topics that are not entirely
chemical by nature. 
Some of the items most often encountered in crime laboratories, and the information
sought in regard of them , are: (1) Body fluids and viscera to be analysed for poisons,
drugs or alcohol, quantitation of which may assist in determining the dosage taken or the
person's behavior prior to death; (2) Licit and licit pills, vegetable matter, and pipe
residues for the presence of controlled substances; (3) Blood, saliva, and seminal
stains, usually in dried form, to be checked for species, type and genetic data. (4)
hairs to determine animal or human; if human, the race, body area of originated general
characteristics; (5) Fibers, to determine type ( vegetable, animal, mineral or
synthetic), composition, dyes used, and processing marks; (6)liquor, for alcoholic proof,
trace alcohols, sugars, colourants, and other signs of adulteration; (7)paint, glass,
plastics, and metals, usually in millimeter -sized chips, to classify and compare known
materials; (9) Swabs from the hands of the suspects, to be checked for the presence of
gunshot residue; (10) Debris from a fire or explosion scene, for the remains of the
accelerant or explosive used.
Forensic Toxicology is an interdisciplinary science dealing with and interpretation of
drugs and chemical samples for medical-legal purposes The hybrid and analytical
chemistry, pharmacy toxicology. The Forensic Science Foundation said,Forensic toxicology
is the study and understanding of the harmful effects of external substances introduced
into the living systems within a medical text. There are three major case load and
forensic toxicology laboratories; drug abuse resulting from illegal use of drugs;
paratoxicological aspects of criminal investigations on post mortem cases - analytical
studies in the medical examiner to determine the case.In addition, many forensic
toxicology laboratories assist local hospitals and physicians with diagnoses and patient
care in emergency positions or with those patients requiring complex therapy. The Society
of Forensic Toxicology describes forensic toxicologists as scientist involving the
analysis of tissue and body fluids for drugs and poisons, and who interpret the resulting
information in the judiciary context. The forensic toxicologist as ascertain a chain of
evidence or custody for each sample analysis, and documents the methodology and data
collected, and is therefore prepared to defend the findings in legal hearings or trials.
Along with the establishment of the New York City Medical Examination in 1990, the lst
laboratory forensic laboratory was established. Other cities and counties have
subsequently established similar systems. About thirty percent of medical-legal
investigations are now performed by the medical examiners office rather than coroners
office. 
The most commonly encountered drugs and chemical involved in fatal poisoning include
ethyl alcohol, barbiturates, carbon monoxide, morphine, proxyphene, and
benzodiazepines.The role of ethyl alcohol in death is rarely due to its direct toxic
effects but to its indirect role in accidents.
The circumstance of death in approximately twenty percent of the population require a
thorough medical-legal investigation. The forensic toxicologist provides for the
isolation of chemicals and subsequent analysis in an effort to determine if a chemical
agent played a role in the cause of death. At autopsy the forensic pathologist collects
postmortem specimens. The specimens are specially provided by the toxicologist for the
subsequent analysis. The distribution of the chemicals in the body provides information
about the mode of exposure(ingestion, injection, inhalation, and s on) and the time of
exposure relative to death. 
The forensic toxicologist has a number of isolation techniques (steam
distillation, selective solvent extraction, microdiffusion), depending on the tissue and
the analyte,
which allow for the recovery of drugs and chemicals from biological samples. Once the
substance for the analysis has been removed from the tissue specimen, the forensic
toxicologist uses chromatography, spectrophotometry, and immunoassays to qualitatively
and quantitatively to determine the drug. 
The forensic toxicologist must then interpret the analytical data collected from the
analytical methods. Pharmaceutical manufacturers are one source of toxicology information
relative to compounds that they have developed, manufactured, and marketed. The published
literature provides the second source of toxicology data. The greatest challenge facing
the forensic toxicologist is the interpretation of combinations of various drugs and
chemicals and their complex interactions. 
Another rather large part of foresic science is pathology. It is a large field including
identifying the decedent, determining time of death, autopsies, and determining the cause
of death. It requires a lot of patience and concentration to make sure you find every
piece of evidence and clues to the death.
Identifying the decedent standardly incorporates physical description, scars and marks,
fingerprints, photographs, Age, Dental features, Radiological evidence, blood factors,
and medical indications. 
Another way is through Genetic Fingerprints. The human body is composed of millions of
microscopic cells. Each cell contains an unique code, the genetic code that determines
what we look like and how we develop. The code takes the form of long strings of
molecules called DNA. No two people have identical DNA unless they are identical twins. 
The process of making DNA profile may begin with a scrape of stained clothing found at
the scene of the crime. Atuft of hair or droplets of body fluids such as blood can be
used too. The material is soaked so that any body cells in the stain come away from the
cloth and into the liquid. The cells are then broken open to let out the long threads of
DNA. These are treated chemically to cut them into tiny pieces. A block of these DNA
fragments is then placed at one end to the other, the pieces of DNA move through the
jelly in the direction of the electric currents. The process is called electrophoresis.
The shorter pieces of DNA can move through the jelly more easily than the longer pieces.
After a while, the DNA separates out into bands according to the size although at this
stage the bands are invisible.
The pattern of the DNA bands then has to be transferred to a nylon sheet. The nylon sheet
is then treated to make the DNA radioactive. When photographic film is laid on top of the
nylon sheet for a while and then developed chemically, the bands of DNA appear as dark
stripes of different thickness on the film. If the pattern of bands produced by cells
found at the scene of the crime exactly matches the pattern made by cells collected from
the suspect then the body cells from both samples must belong to the suspect and he or
she must have been present at the scene of the crime. With a good sample, that is rich in
DNA, the chance of two people producing the same genetic fingerprint is only one in 2.7
million, which is good enough for a court of law. However, people who are related do have
similarities in their DNA. The chances of two related people producing the same genetic
fingerprint is as high as 1 in 200. If there is not enough good quality DNA material for
a reliable test, the chance of two people producing the same the genetic fingerprint
could rise to 1 in 50. So the value of DNA profiling depends on the circumstances of the
case. 
Fingerprints are infallible means of identification. In addition to their value in the
apprehension of criminals, fingerprints can ensure personal identification of
humanitarian reasons, such as in cases of amnesia, missing persons, or unknown deceased.
Fingerprints are invaluable in effecting identifications in tragedies such has fire,
flood, and vehicle crashes. In criminal matters, besides establishing the identity of the
arrested person, fingerprint records provide a history of known offenders, or indicate
when a person is a offender. The vast majority of fingerprints maintained in the
Identification Division of the Federal Bureau of Investigation of the United States, the
largest repository of fingerprints in the world, are for civil records. 
The latest fingerprint section of the Federal Bureau of Investigation deals with the
identification of single or latent (hidden) fingerprints developed at the scene of a
crime or upon articles of evidence. This generally involves the examination of
fragmentary latent finger, palm or even foot developed by appropriate processes on
objects associated with various crimes. 
The traditional way of dusting surfaces for fingerprints is still used most of the time.
In most cases it works very well, but sometimes different methods are needed. Forensic
scientists can now use a small portable laser to look for fingerprints. The scientists
paints the scene of crimes with the laser beam. As the laser beam sweeps across doors,
walls and furniture, any fingerprints on them glow because they are fluorescent. Some
atoms in the print absorb the laser light, and then release it again in a for of a burst
of light. All of these tiny flashes combine to make
the whole print glow when the laser beam hits it. The technique of laser-sweeping enables
large areas to be searched quickly, and prints in odd places can be found. Dusting the
same surfaces with powder would take much longer and prints in unlikely places could be
miss altogether. Prints found by a laser can also be dusted with fluorescent powder to
make them show up even more clearly so they can be photographed. 
Fibers play an important role in crime detection. A fiber found on a suspect may match
fibers from clothings, carpets or upholstery at the scene of the crime. Or a fiber from
the suspect's clothing maybe found at the scene of the crime. Sample of fibers from the
suspect and from the scene of the crime can be compared in many ways to see if they
match. The samples may appear similar through the microscope when viewed under ordinary
light conditions, but one sample may look quite different under ultraviolet light. Any
dyes present in the fibers can be dissolved out and then separated by thin-layer
chromatography. 
In a simple form of chromatography, a solution of the dye is soaked up by a strip of
absorbent paper. Different substances in the dye move along the paper at different rates,
so they become separated into distinct bands of diffe- rent colors. If two samples of dye
are identical, they will produce identical set of bands. If all of the above tests show
the fibers to be similar, they are finally analyzed to make sure they are made of the
same substance. 
Analysis can also be used to find the source of fibers. For example, in one recent case,
analysis of fibers revealed that they came from a single batch of a particular
manufacturer's space carpets. Automobiles fitted with the carpets were traced, and the
criminal was found among the owners. 
Like thin film chemography, gas chromatography is used to separate substances in
mixtures, however, in this case, substances are in gaseous form. One of the most common
applications of gas chromatography in forensic science is for the measurement of the
alcohol content in the blood. This is carried out when a driver has failed a breath test,
and is suspected of having drunk too much alcohol. 
A stream of nitrogen gas is blown through a sample of the driver's blood. The nitrogen
removes alcohol from the blood, and carries it as a vapour through a long tube. This is
packed with a material that holds back any other substances that have been removed from
the body by the nitrogen. At the far end of the tube, any alcohol that emerges is
detected and measured by an electronic device. As the original amount of blood in the
sample is known, the concentration of alcohol that was in it can then be calculated. In
recent years, gas chromatography has become one of the most important techniques in
forensic science and has led to thousands of successful prosecutions. 
FORENSIC SCIENCE TIMELINEBCE Evidence of fingerprints in early paintings and rock
carvings of prehistoric humans
700s Chinese used fingerprints to establish identity of documents and clay sculpture, but
without any formal classification system.
1000 Quintilian, an attorney in the Roman courts, showed that bloody palm prints were
meant to frame a blind man of his mother's murder.
1248 A Chinese book, Hsi Duan Yu (the washing away of wrongs), contains a description of
how to distinguish drowning from strangulation. This was the first recorded application
of medical knowledge to the solution of crime.
1609 The first treatise on systematic document examination was published by Fran?ois
Demelle of France
1686 Marcello Malpighi, a professor of anatomy at the University of Bologna, noted
fingerprint characteristics. However, he made no mention of their value as a tool for
individual identification.
1784 In Lancaster, England, John Toms was convicted of murder on the basis of the torn
edge of wad of newspaper in a pistol matching a remaining piece in his pocket. This was
one of the first documented uses of physical matching.
1800s Thomas Bewick, an English naturalist, used engravings of his own fingerprints to
identify books he published.
1810 Eugne Fran?ois Vidocq, in return for a suspension of arrest and a jail sentence,
made a deal with the police to establish the first detective force, the Surete of Paris.
The first recorded use of question document analysis occurred in Germany. A chemical test
for a particular ink dye was applied to a document known as the Konigin Hanschritt.
1813 Mathiew Orfila, a Spaniard who became professor of medicinal/forensic chemistry at
University of Paris, published Traite des Poisons Tires des Regnes Mineral, Vegetal et
Animal, ou Toxicologie General l. Orfila is considered the father of modern toxicology.
He also made significant contributions to the development of tests for the presence of
blood in a forensic context and is credited as the first to attempt the use of a
microscope in the assessment of blood and semen stains.
1823 John Evangelist Purkinji, a professorprofessor of anatomy at the University of
Breslau, Czecheslovakia, published the first paper on the nature of fingerprints and
suggested a classification system based on nine major types. However, he failed to
recognize their individualizing potential.
1828 William Nichol invented the polarizing light microscope.
1830s Adolphe Quetelet, a Belgian statistician, provided the foundation for Bertillon's
work by stating his belief that no two human bodies were exactly alike.
1831 Leuchs first noted amylase activity in human saliva.
1835 Henry Goddard, one of Scotland Yard's original Bow Street Runners, first used bullet
comparison to catch a murderer. His comparison was based on a visible flaw in the bullet
which was traced back to a mold.
1836
James Marsh, an Scottish chemist, was the first to use toxicology (arsenic detection) in
a jury trial.
1839
H. Bayard published the first reliable procedures for the microscopic detection of sperm.
He also noted the
different microscopic characteristics of various different substrate fabrics.
1851
Jean Servais Stas, a chemistry professorprofessor from Brussels, Belgium, was the first
successfully to identify
vegetable poisons in body tissue.
1853
Ludwig Teichmann, in Kracow, Poland, developed the first microscopic crystal test for
hemoglobin using
hemin crystals.
1854
An English physician, Maddox, developed dry plate photography, eclipsing M. Daguerre's
wet plate on tin
method. This made practical the photographing of inmates for prison records.
1856
Sir William Herschel, a British officer working for the Indian Civil service, began to
use thumbprints on
documents both as a substitute for written signatures for illiterates and to verify
document signatures.
1862
The Dutch scientist J. (Izaak) Van Deen developed a presumptive test for blood using
guaiac, a West Indian
shrub.
1863
The German scientist Schonbein first discovered the ability of hemoglobin to oxidize
hydrogen peroxide making
it foam. This resulted in first presumptive test for blood.
1864
Odelbrecht first advocated the use of photography for the identification of criminals and
the documentation of
evidence and crime scenes.
1877
Thomas Taylor, microscopist to U.S. Department of Agriculture suggested that markings of
the palms of the
hands and the tips of the fingers could be used for identification in criminal cases.
Although reported in the
American Journal of Microscopy and Popular Science and Scientific American, the idea was
apparently never
pursued from this source.
1879
Rudolph Virchow, a German pathologist, was one of the first to both study hair and
recognize its limitations.
1880
Henry Faulds, a Scottish physician working in Tokyo, published a paper in the journal
Nature suggesting that
fingerprints at the scene of a crime could identify the offender. In one of the first
recorded uses of fingerprints
to solve a crime, Faulds used fingerprints to eliminate an innocent suspect and indicate
a perpetrator in a
Tokyo burglary.
1882
Gilbert Thompson, a railroad builder with the U.S Geological Survey in New Mexico, put
his own thumbprint
on wage chits to safeguard himself from forgeries.
1883
Alphonse Bertillon, a French police employee, identified the first recidivist based on
his invention of
anthropometry.
1887
Arthur Conan Doyle published the first Sherlock Holmes story in Beeton's Christmas Annual
of London.
1889
Alexandre Lacassagne, professorprofessor of forensic medicine at the University of Lyons,
France, was the
first to try to individualize bullets to a gun barrel. His comparisons at the time were
based simply on the number
of lands and grooves.
1891
Hans Gross, examining magistrate and professor of criminal law at the University of Graz,
Austria, published
Criminal Investigation, the first comprehensive description of uses of physical evidence
in solving crime. Gross
is also sometimes credited with coining the word criminalistics.
1892
(Sir) Francis Galton published Fingerprints, the first comprehensive book on the nature
of fingerprints and their
use in solving crime.
Juan Vucetich, an Argentinean police researcher, developed the fingerprint classification
system that would
come to be used in Latin America. After Vucetich implicated a mother in the murder of her
own children using
her bloody fingerprints, Argentina was the first country to replace anthropometry with
fingerprints.
1894
Alfred Dreyfus of France was convicted of treason based on a mistaken handwriting
identification by Bertillon.
1896
Sir Edward Richard Henry developed the print classification system that would come to be
used in Europe and
North America. He published Classification and Uses of Finger Prints.
1898
Paul Jesrich, a forensic chemist working in Berlin, Germany, took photomicrographs of two
bullets to
compare, and subsequently individualize, the minutiae.
1901
Paul Uhlenhuth, a German immunologist, developed the precipiten test for species. He was
also one of the first
to institute standards, controls, and QA/QC procedures. Wassermann (famous for developing
a test for
syphilis) and Schutze independently discovered and published the precipiten test, but
never received due
credit.
1900
Karl Landsteiner first discovered human blood groups and was awarded the Nobel prize for
his work in 1930.
Max Richter adapted the technique to type stains. This is one of the first instances of
performing validation
experiments specifically to adapt a method for forensic science. Landsteiner's continued
work on the detection
of blood, its species, and its type formed the basis of practically all subsequent work.
1901
Sir Edward Richard Henry was appointed head of Scotland Yard and forced the adoption of
fingerprint
identification to replace anthropometry.
Henry P. DeForrest pioneered the first systematic use of fingerprints in the United
States by the New York
Civil Service Commission.
1902
professor R.A. Reiss, professor at the University of Lausanne, Switzerland, and a pupil
of Bertillon, set up one
of the first academic curricula in forensic science. His forensic photography department
grew into Lausanne
Institute of Police Science.
1903
The New York State Prison system began the first systematic use of fingerprints in United
States for criminal
identification.
At Leavenworth State Prison, Kansas, Will West, a new inmate, was differentiated from
resident convict Will
West by fingerprints, not anthropometry. They were later found to be identical twins.
1904
Oskar and Rudolf Adler developed a presumptive test for blood based on benzidine, a new
chemical
developed by Merk.
1905
American President Theodore Roosevelt established Federal Bureau of Investigation (FBI).
1910
Victor Balthazard, professor of forensic medicine at the Sorbonne, with Marcelle Lambert,
published the first
comprehensive hair study, Le poil de l'homme et des animaux. In one of the first cases
involving hairs, Rosella
Rousseau was convinced to confess to murder of Germaine Bichon. Balthazard also used
photographic
enlargements of bullets and cartridge cases to determining weapon type and was among the
first to attempt to
individualize a bullet to a weapon.
Edmund Locard, successor to Lacassagne as professor of forensic medicine at the
University of Lyons,
France, established the first police crime laboratory.
Albert S. Osborne, an American and arguably the most influential document examiner,
published Questioned
Documents.
1912
Masaeo Takayama developed another microscopic crystal test for hemoglobin using
hemochromogen crystals.
1913
Victor Balthazard, professor of forensic medicine at the Sorbonne, published the first
article on individualizing
bullet markings.
1915
Leone Lattes, professor at the Institute of Forensic Medicine in Turin Italy, developed
the first antibody test for
ABO blood groups. He first used the test in casework to resolve a marital dispute. He
published L'Individualita
del sangue nella biologia, nella clinica, nella medicina, legale, the first book dealing
not only with clinical issues,
but heritability, paternity, and typing of dried stains.
1915
International Association for Criminal Identification, (to become The International
Association of Identification
(IAI), was organized in Oakland, California.
1916
Albert Schneider of Berkeley, California first used a vacuum apparatus to collect trace
evidence.
1918
Edmond Locard first suggested 12 matching points as a positive fingerprint
identification.
1920
Locard published L'enquete criminelle et les methodes scientifique, in which appears a
passage that may have
given rise to the forensic precept that Every contact leaves a trace.
Charles E. Waite was the first to catalog manufacturing data about weapons.
1920s
Georg Popp pioneered the use of botanical identification in forensic work.
Luke May, one of the first American criminalists, pioneered striation analysis in tool
mark comparison,
including an attempt at statistical validation. In 1930 he published The identification
of knives, tools and
instruments, a positive science, in The American Journal of Police Science.
Calvin Goddard, with Charles Waite, Phillip O. Gravelle, and John H Fisher, perfected the
comparison
microscope for use in bullet comparison.
1921
John Larson and Leonard Keeler designed the portable polygraph.
1923
Vittorio Siracusa, working at the Inst