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natural or synthetic compounds used for physiological effects
o study of drugs and posions and their adverse affects on the human system. Subfields include:
T or F: Scientific evaluation of crime-scene evidence can usually overcome the results of a poorly conducted criminal investigation
T or F: the lead investigator will immediately proceed to gain an overview of the situation and develop a stately for the systematic examination of the crime scene during the final survey
T or F: crime-scene notes should be written from memory back at the lab
being moved should be observed but not recorded
for lab examination, sophisticated lab instruments or technical expertise can salvage the
situation and attain the desired results
T or F: the techniques of physical evidence collection require a highly skilled individual who
must specialize in this area of investigation!
T or F: failure to protect a crime scene properly may rest in the destruction or altering of
T or F: the boundaries of the crime scene, denoted by crime-scene tap, rope, or traffic cones, should encompass only the center of where the scene occurred!
T or F: the note-taking process beings with the call to a crime-scene investigator to report a scene
position of witnesses, and relation of people to on another in the scene
succession and the photographs should include the area in which the crime actually took place
and all adjacent areas where important acts occurred
strip or line search, grid search, spiral search method, wheel/ray search, and the quadrant or
properties of evidence that can only be associated with a general group and not with a common source (i.e. blood type)
anything that establishes a link between a crime and a person
encompasses all objects that can establish or disprove whether a crime has been committed or can link a crime and its victim or its perpetrator
the crime-scene search is undertaken to locate physical evidence
-prevent the immediate destruction of evidence
-incident to a lawful arrest
-National Security and border searches
the basic building block of DNA, consisting of a phosphate, a deoxyribose sugar, and a nitrogen base.
Region along the DNA strand that provides coding information for the synthesis of proteins.
An organic polymer molecule made up of a linear chain of amino acid building blocks. They are essential to living organisms and their sequence of amino acids is dictated by the DNA genetic code.
polymerase chain reaction; laboratory method for the rapid replication of regions of DNA.
restriction fragment length polymorphism.
short tandem repeat; a region of DNA in which a small sequence of nucleotide (2 to 6 nucleotides) is repeated multiple times.
The process of separating the two strands of DNA into individual strands.
To pair nucleotides in complimentary DNA strands together by forming hydrogen bonds.
Combined DNA Identification System, developed by the FBI to store DNA information in searchable computer database.
A slightly yellow solution obtained by first allowing blood to clot and then removing the solids by centrifugation. Differs from plasma since it contains none of the clotting factors (principally fibrinogen and platelets) found in plasma.
A globular protein containing four iron-based heme subunits that carries oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.
one several possible variants of the genetic code at a specific location along the DNA molecule.
A presumptive blood test using phenolphthalein and hydrogen peroxide. If blood is present, the indicator immediately turns pink.
The tendency of the molecules at the surface of a liquid to behave as if they were part of an elastic membrane.
A bloodstain formed primarily by the action of gravity alone.
Angle of impact
The angle formed between the direction of a blood drop and the plane of the surface it strikes.
The small droplets of blood distributed around a larger drop of blood.
A pattern created when a wet, bloody surface comes in contact with another surface to form a print-like pattern.
all unauthorized personnel must be excluded from crime scenes
when arriving on the scene of the crime, they are responsible for taking steps to preserve and protect the area to the greatest extent possible, and this person must rely on his or her training to deal with any violent or hazardous circumstances
at a crime scene, first priority should be given to obtaining medical assistance for individuals in need of it and attempting got minimize disturbance of evidence
even though no unauthorized personnel are admitted to the scene, an accurate log must
be kept of those who do enter and exit the scene and the time they do so
three methods for recording the crime scene
the crime-scene notes should include a precise record of personnel movements in and out of the scene starting with them
before located evidence is collected, it must be fully described in the investigator’s notes
the most important prerequisite for photographing a crime scene is to have it be unaltered
photographs of physical evidence must include overviews as well as closeups to record the details of objects
the most commonly used camera for crime-scene photography, can be
digital or film
a digital camera captures light on a light-sensitive microchip
the succession of photographs taken at a crime scene is overview
photographs and then close-up photographs last
to ensure that their digital images will be admissible, many jurisdictions have developed or are developing strict protocols and guidelines for the use of digital photography to avoid the possibility of enhancement or doctoring of crime-scene photographs
an investigator will draw roughly at the scene to show its dimensions and pertinent objects
constructed with care and concern for aesthetic appearance and must be drawn to scale
program that provides an extensive symbol library and may
create a 3-D sketch
detailed search of the crime scene for physical evidence must be
conducted in this manner
besides the more obvious items of physical evidence, possible carriers of trace evidence must be collect for detailed examination in the lab
whenever possible, trace evidence is not to be removed from the object that bears it
as a matter of routine, all items of clothing are to be air-dried before packaging
the possibility of future legal proceedings requires that a chain of custody be established with respect to the possession and location of physical evidence
most physical evidence collected at the crime scene will require the
accompanying submission of standard/reference material for comparison purposes
in the case of Mincey vs. Arizona, the Supreme Court restricted the practice of conducting an unwarranted search at a homicide scene
in the case of Michigan vs. Tyler, the Supreme Court felt with search and seizure procedures at an burned and unattended scene
an element is a substance that cannot be broken down into other substances;
a compound is a substance consisting of 2 or more elements combined in a fixed ratio
when two nitrogen bases in complimentary strand connect to form a hydrogen bond, holding the two DNA strains together. Adenine (A) paris only with Thymine (T) and Guanine (G) paris only with Cytosine (C) in DNA.
The strand of DNA and its associated proteins found in the nucleus of a cell that carries its genetic information.
the chromosome inherited only through the father and passed along only to male offspring.
a strand of DNA in which the sequence of bases matches those of another strand of DNA according to pairing rules. Thus, if the original strand contains an "A" nucleotide at a particular location, the complimentary strand would have a "T" nucleotide at the equivalent location.
deoxyribonucleic acid; the basic genetic molecule of living organisms composed of repeating three groups (nucleotides): a phosphate, a deoxyribose sugar, and a nitrogen base.
a protein that catalyzes a chemical reaction; affects the rate of a chemical reaction without being consumed by the reaction.
A protein that catalyzes a specific biochemical reaction without being consumed in the reaction.
Completing a complimentary DNA strand from a template strand.
the process of separating DNA fragments based upon their change and size. Charged DNA fragments are placed in a gel bed and moved through the medium by applying an electric current. Shorter fragments move fastest and farthest through the gel while longer fragments move the least.
the process of joining together complimentary strand of DNA through base-pairing.
(also called "junk", "non-coding" or "nonsense" DNA) a region of DNA that shows a great degree of variability in a population and do not code for any known protein.
a specific position on the DNA strand.
mtDNA; a small circle of DNA that resides outside the nucleus in the cellular mitochondria. mtDNA is only inherited from mothers and passed to all offspring.
an inheritable change in the base sequence of DNA.
a specific group of people defined by geography, race, of other defining features.
a protean that locates a specific DNA sequence and cuts the DNA strand at that location.
Variable number tandem repeat; a region of DNA in which a larger sequence of nucleotides (up to fifty nucleotides) is repeated multiple times.
The bloodstains formed by a force in addition to gravity.
The major plasma protein in human blood (~60% of plasma proteins) that is soluble in water and salt solutions. It is coagulated by heat and is responsible for maintaining plasma osmotic pressure (fluid balance) and transporting biomolecules.
An enzyme that breaks down starch and glycogen into its component simple sugars (mainly glucose).
A Y-shaped protein molecule that can combine with a foreign antigen to disable or destroy the antigen.
Any substance that can stimulate the production of antibodies.
A yellow or green fluid secreted by the liver and stored in the gall bladder primarily to aid
digestion of lipids.
Blood pattern analysis
The analysis of bloodstains found at a crime scene that attempts to
provide an understanding of how the blood patterns were physically formed.
The soft, spongy tissue found in the center of bones. It produces most of the cellular components of blood from stem cells.
A substance that accelerates a chemical reaction with being consumed in the reaction.
The emission of light from chemical reactions without the emission of heat
An experiment that can indicate the presence of a particular component in the sample with a very high degree of certainty.
An immunoassay technique in which antibodies to a specific antigen are made and isolated from a rabbit's serum. In the analysis, a sample is first mixed with the anti-serum and any antigen present in the sample completely reacts with the anti-serum. Measuring
the amount of the antigen bound to an enzyme tells how much antigen was in the original sample.
The branch of science that deals primarily with the behavior of liquids and gases in motion. In blood analysis, it focuses on how blood flows and typically involves calculations of density, velocity, and viscosity.
A chemical that is oxidized by hydrogen peroxide when hemoglobin is present to emit light though fluorescence (activated by ultraviolet light at 365 nm and emits light at 450 - 490 nm).
The phenomenon that occurs when a molecule absorbs light at one wavelength and then emits light at a different wavelength.
A protein with covalently bonded sugar subunits attached at specific amino acids (primarily serine, threonine, and asparagine). Found in plasma membranes and in most secreted proteins.
High velocity impact spatter (HVIS)
A bloodstain pattern caused by a high velocity impact to a blood source, usually observed when the object is moving at speeds of 100 ft./sec. (30 m/sec.) or faster.
A technique of identifying and measuring the amount of a substance in the blood primarily through antigen-antibody interactions.
The broad branch of science that deals with all aspects of the immune system.
Low velocity impact spatter (LVIS)
A bloodstain pattern caused by a low velocity impact to a blood source, usually at speeds up to about 5 ft/sec.
A chemical that is oxidized by hydrogen peroxide when hemoglobin is present to emit light though chemiluminescence.
Medium velocity impact spatter (MVIS)
A bloodstain pattern caused by a medium velocity impact to a blood source, usually when the velocity of the object is between 5 and 25
An artificially stimulated antibody that is more uniform than our natural antibodies that attacks and binds to only one site on a chosen antigen. Prepared using spleen cells that have been activated to produce antibodies and then fused to fast-growing cell strains that are selected and cultured to generate the antibody.
The presumptive test reagent for saliva through detection of amylase.
The liquid portion of blood that comprises about 55% of its volume consisting of a complex mixture of cellular, biochemical, and inorganic components in a water-based solution.
A cellular component of blood accounting for about 1% of blood cells that are important in blood clotting and self-repair processes of blood vessels. Platelets have no nucleus but do contain some RNA and other cellular structures.
An enzyme that catalyzes the oxidation of a substrate from the reduction of hydrogen peroxide.
An analysis which can screen for, but not confirm the presence of a particular substance in a sample.
A technique that is similar to the EMIT immunoassay technique except a radioactive tracer is linked to the final step antigen for analysis.
Red blood cells (erythrocytes, RBC)
The flexible, disc-shaped cells, concave on both sides.that account for about 96% of the cellular portion of blood. Their primary function is to
carry oxygen from the lungs to the cells and return waste carbon dioxide from the cells
back to the lungs. The main chemical component of RBC’s is protein called hemoglobin,
which accounts for about 90% of the dry weight of a red blood cell.
Ring Precipitin Test
An immunoassay test in which a soluble antigen reacts to form a
precipitate when it combines with a specific antibody in the presence of an electrolyte.
A body fluid produced by the salivary glands of the mouth that is comprised mostly of
water with small amounts of proteins, enzymes and other substances.
A person who secretes blood antigens in other body fluids besides blood.
The semi-fluid containing cells, proteins, amino acids, hormones, carbohydrates, and a variety of other inorganic and organic compounds. It is produced by the male reproductive system to carry sperm.
Seminal Acid Phosphatase
The enzyme found in high levels in semen.
The field of science that deals specifically with the study of serum or other body fluids such as blood, saliva, urine, semen. and includes the diagnostic identification of antibodies found in the serum and other body fluids.
Sickle cell anemia
The disease from a single change of an amino acid in hemoglobin (replacement of a glutamic acid for a valine). As a result, the red blood cells change to a sickle-shape under low oxygen levels, often clogging arteries and leading to anemia.
Imparts some resistance to malaria.
The male reproductive cell.
A substance upon which an enzyme works.
A mostly saltwater solution that is secreted by sweat glands in a attempt to cool the body by evaporation.
The addition of blood or blood components from a donor directly into the blood stream of a recipient.
The solution comprised mostly of water and salts used by the body to eliminate soluble waste products and to regulate ion concentrations.
The resistance of a liquid to flow under stress.
The gelatinous fluid filling the eyeball behind the lens
While blood cells (leucocytes)
A cellular component of blood that consists of a large and diverse group of cell types that contain nuclei and organelles. They are round to irregularly shaped cells accounting for about 3% of the total number of blood cells, whose primary
responsibility is to effect cellular repair and fight off disease and infection.
large, high molecular weight molecule formed by joining together a large number of molecules of low molecular weight
- Best are the long bones
- Measurements and use formula
- Give range of 1 in. as an estimate for stature
- Skull, maxcilla, mandible, clavicle, scapula, vertebrae (cervical, thoracic, lumbar, sacrum) humorous, radius, ulna, pelvic/ilium,Human bone vs. animal bone
a part of bone separated from the main body of the bone by a layer of cartilage and subsequently uniting with the bone through further ossification
studying organisms and their environments and using these relations to look for observable changes or patterns that can provide unique legal information
· pollen, spores, and similar materials
- Identify with species
- Plants, animals, fungi, protists, monera
- Kingdom, phylum, class, order, family, genus, species
o Track a suspect’s or victim’s movements
o Validating alibis and proposed timelines of events
o Determining how long someone has been dead
o Dealing with issues of plant=based poisons and toxicology
o Treesà ages
o Nasal cavity and hair pollen
o Cause of death: poisonous and edible often look the same (mushrooms)
o Finding bodies (corpse finder, grows on disturbed ground)
o Application of insects to legal issues
§ Establishing timelines
§ Movement of the corpse, manner and cause of death
§ Association of suspects with the death scene
§ Detection of toxins or drugsà insect larvae
Fresh stage -bloated stage- decay stage-post-decay stage- dry stage
· Flies begin oviposition as soon as they discover a body
· Succession on a corpse is predictable
· Insect development is predictable
· Metabolic activity by large numbers of maggots raises temperature of the cadaver significantly
· Generally increases with larval density
· May result in dramatically shorter development times
- Sample molecules are ionized by electron beams which are then deflected by magnetic field
- for ions of the same charge the angle of deflection in proportional to the ion’s mass
o Electrons in around nucleus with quantized energy states
o when in a state, no energy is radiated but when it changes states, energy is emitted or gained equal to the energy difference between the states
o emission from higher to lower, absorption from lower to higher
o only discrete and defined quantities or states are possible
· Qualitative and quantitative
· Level of analysis required
· Destructive or non-destructive
· Availability of instrumentation
· A mixture is injected into the GC where the mixture is vaporized. The gas mixture travels through a GC column, where the compounds become separated. Those separated compounds the immediately enter the mass spectrometer.
o electrons moving from lower energy to higher energy- absorption
o electrons moving from higher to lower- emit
o Radiation from 500-4000 cm
o Vibrational mode must have a change in dipole moment in the nartransition. Energy of the transition is dependent upon the strengths of the bonds and geometric structure.
- Cuts across socio-economic levels
- >75% of forensic investigations involve drug use
- not victimless crimes
§ Physical properties and names
§ Chemical reactivities
§ Safe handling
§ Safety and first aid
§ As commonly occurs in pesticides, shrimp, pressure treated wood, old wallpaper
§ Stopped enzymes normal function
§ Accumulates in the body
§ Used as a poison in WWI
o substance has a high potential for abuse
o no currently accepted medical use
o lack of accepted safety for use of substanceheroin, lsd, marijuana, meth
o highest potential for abuse
o currently accepted medical use in treatement
o abuse of the substance may lead to severe psychological or physical dependence
o morphine, cocaine,methandone, PCP, meth
o some potential for abuse
o currently accepted medical use
o may lead todependence
o steroids, codeine, hydrocodone with aspririn or Tylenol
o low potential for abuse
o medical use
ingest--> most alcohol absorbed in small intestine--> in blood stream affects brain--> affects from front of brain to back
- Amount taken in and period over which it is taken are the two most important factors
· minimum temp at which fuel vapor will ignite
· lowest temp where a fuel will vaporize sufficiently to form an ignitable mixture with air
o Size and shape of bullet/case
o Rifling match
o Firing pin/ case impression match
o Striations on bullet match
o Serial numbers
§ Grooves and lands
§ Striations- microscopic imperfections from rifling tools or chips of steel from broach cutter
§ No two riles barrels, even those made in succession, will have identical striation markings
§ Compare striations, grooves/lands, twist direction and angles between test and sample bullets
§ Problem: each successive bullet will be a little different due to wear of barrel so matchup will not be perfect
- comparison microscope
Fortuitous accidents, researching old folklore traditions, hard work (isolating active ingredient and tweaking it to make something new)
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