forensic science Flashcards
Matthieu Orfila.
The father of forensic toxicology. Spain published first scientific treatise on the detection of poisons and their effects on animals
The eleven sections of forensic science
- criminalistics
- digital & multimedia sciences
- engineering sciences
- general
- Odontolgy
- biology
- jurisprudence
- physical anthropology
- behavioral studies
- questioned documents
- toxicology
Alphonse Bertillion
The first scientific system of personal identification. Anthropometry- a systimatic procedure of body measurements to identify one person from another
Francis Galton 1822-1911
The first difinitive study of finger prints & devolved a method for filing them.
Calvin Goddard 1891-1946
Figured out whether a particular fun has fired a bullet. Requires comparison of the bullet and suspects weapon.
Hans Gross 1847-1915
Wrote the first treatise describing the application of disciplines to the field of criminal investigation. He detailed the assistance of ppl from the fields of microscopy, chemistry, physics, mineralogy, zoology, botany, anthropology, and fingerprinting.
Edmond locard 1877-1966
Started a police laboratory, useing the examples of gross, but with a fine toothed comb. Became founder and director of the institute of criminalistics @university of Lyons.
When a person comes in contact with an object or person, a cross transfer of materials occurs. (Locards exchange principal)
Sir Arthur Conan Doyal
Created Sherlock Holmes. First applied newly developing principals of serology
J. Edgar Hoover.
Orginized a national laboratory that offered forensic services to all law enforcement agencies in the country. The FBI is the worlds largest forensic laboratory
Divisions and units of a modern forensic lab
Physical science unit - the process of the scientific method.
Biology unit - responsible for DNA profiling, comparison of organic materials
Fire arms unit- examines firearms discharged bullets, shotgun shells, and ammunitions of all kinds
Documents examination unit - studies hand writing/ type writing
Photography unit - examines and records physical evidence. Digital imaging, infrared, ultra violet,, x-ray photographs
Toxicology unit - examines bodily fluids And organs to determine the presence or absence of drugs and poisons.
Latent fingerprint unit- processes and examine evidence when submitted in conjunction with other laboratory examinations
Voiceprint analysis unit - involving telephoned threats or tape recorded messages. Jing a sound spectograph investigators can use this instrument that transforms speech into a visual display called a voiceprint.
Crime scene investigation unit- this unit dispatches specially trained personnel to the crime scene to collect and preserve physical evidence that will later be processed at the crime laboratory.
Functions of a forensic scientist
Relies primarily on the scientific knowledge and skill in performing analyses in the laboratory. A good deal of forensics time is spent in the courtroom. A forensic scientist must not only analyze evidence, but convince a jury to accept the conclusions from his evidence
Scientific method
A process that uses strict guidlines to ensure careful and systematic collection organization and analysis of information.
Physical property
The behavior of a substance without the alteration of its composition through a chemical reaction… Weight, volume, color, boiling/melting point.
Chemical property
Describes the behavior of a substance when it reacts or combines with another substance.
Weight
A property of matter that depends on both the mass of a substance and the effects of gravity on that mass
Mass
A constant property of matter that reflects the amount of material present.
Refraction
The bending of a lightwave as it passes from one medium to another
Refractive index
The ratio of the speed of light in a vacuum to its speed given substance
Atom
The smallest unit of an element which is not divisible by ordinary chemical means. Atoms are made up of electrons, protons and neutrons plus other subatomic particles
Tempered glass
Glass that is strengthened by introducing stress through rapid heating and cooling of the glass surfaces
Laminated glass
Two sheets of ordinary glass bonded together with a plastic film
Matter
All things of substance;matter is composed of atoms or molecules
Element
A fundamental particle of matter, an element cannot be broken down into simpler substances by chemical means
Periodic table
A chart of elements arranged in a systematic fashion, vertical rows are cAlled groups or families, and horizontal rows are called series, elements in a given row have similar properties.
Compound
A pure substance composed of two or more elements
Physical state
A condition or stage in the form of matter, liquid, solid, gas
Solid
A state of matter in which the molecules are held tightly
Liquid
A state of matter in which molecules are in contact but are not rigidly held in place
Gas
A state of matter in which the attractive forces btw molecules are small enough to permit them to move with complete freedom
Sublimation
A physical change from the solid state directly into the gaseous state
Phases
A uniform body of matter; different phases are separated by definite visible boundaries
Organic
Describes a substance composed of carbon and often smaller amounts of hydrogen, oxygen, nitrogen, chlorine, phosphorus or other elements
Inorganic
Describes a chemical compound not based on carbon
Spectrophotometry
An analytical method for identifying a substance by its selective absorption of different wavelengths of light.
Chromatography
any of several analytical techniques for separating organic mixtures into their components by attraction to a stationary phase while being propelled by a moving phase.
Electrophoresis
A technique for separating through migrations on a support medium while under the influence of an electrical potential. For example dried blood in application to the characterization of DNA.
Visible light
Colored light ranging from red to violet in the electromagnet field
Wave length
The distance btw the crests of adjacent waves
Frequency
The number of waves that pass in a given point per second
Electromagnet spectrum
The entire range of radiation energy from the most energetic cosmic rays to the least energetic ratio waves
X ray
A high energy short wave length form of electromotive radiation.
Laser
An acronym for light amplification by stimulated emission of radiation light that has all it’s waves pulsating in unison
William Henrys law
When a volatile chemical compound is dissolved in Liquid and is brought to equilibrium with air, there is a fixed ratio btw the concentration of the volatile compound in air and it’s concentration in the liquid and this ration remains constant for a given temperature.
Qualitative identification
The analysis of a substance in order to figure out what it’s chemical properties are.
Quantitave analysis
The analysis of a substance to determine the amounts and proportions of its chemical constitutes.
Emission spectrum
Light emitted from a source And separated into its component colors or frequencies.
Continuous spectrum
A type of emission spectrum showing a continuous band of colors all blending into one another.
Line spectrum
A type of emission spectrum showing a series of lines separated by black areas each line represents a definite wavelength or frequency.
A line spectrum shows distinct frequencies or wavelengths of light
Proton
A positively charged particle that is one of the basic structures in the nucleus of an atom
Electron
A negatively charged particle that is one of the basic structures in the nucleus of an atom
Neutron
A particle with no electrical charge that is one of the basic structures in the nucleus of an atom
Nucleus
The core of an atom containing the protons and neutrons
Atomic number
The number of protons in the nucleus of an atom, each element has its own unique atomic number.
Electron orbital
The path of electrons as they move around the nuclei of atoms each orbital is associated with a particular electronic energy level
Excited state
The state in which an atom absorbs energy and an electron. Oves from. Lower to a higher energy level
Atomic mass
The sum of the Number of protons and neutrons in the nucleus of an atom
Isotope
An atom differing from another atom of the same element in the number of neutrons in its nucleus
Alpha particle
A type of radiation emitted by a radioactive element e radiation is composed of helium atoms minus their orbiting electrons
Radio activity
The particle and or gamma ray radiation emitter by an unstable nucleus or isotopes
Beta particle
A type of radiation emitted by a radioactive element the radiation consists of electrons
Gamma ray
A high energy form of electromagnetic radiation emmited by a radioactive element.
X-ray diffraction
An analytical technique for identifying crystalline materials
Virtual image
An image that cannot be seen directly . It can be seen only by a viewer looking through the lens
Real image
An image formed by the actual convergence of light rays on a screen
Objective lens
The lower lens of a microscope, which is positioned directly over the specimen
Eyepiece lens
The lens of a microscope into which the viewer looks; same as the ocular lens
Psychological dependence
Conditioned use of a drug caused by underlying emotional needs
Physical dependence
Physiological need for a drug that has been brought about by regular use. Dependence is characterized by withdrawal sickness when administrated of the drug is abruptly stopped.
Narcotic
An analgesic or painkilling substance that depresses vital body functions such a blood pressure, plus rate, & breathing rate; regular administration of narcotics produce physical dependence.
