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Posted by Jim True on April 25, 2003 3:06 AM. Last Updated October 22, 2006 9:23 PM

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01-06 Review Questions

Correct answers are noted in bold.

Chapter 1

The application of science to law describes Forensic Science.
The fictional exploits of Sherlock Holmes excited the imagination of an emerging generation of forensic scientists and criminal investigators.
A system of personal identification using a series of body measurements was first devised by Alphonse Bertillon.
Francis Galton is responsible for developing the first statistical study proving the uniqueness of fingerprints.
The Italian scientist Leone Lattes devised the first workable procedure for typing dried bloodstains.
The comparison microscope became an indispensable tool of firearm examination through the efforts of Calvin Goddard.
Early efforts at applying scientific principles to document examination are associated with Albert Osborn.
The application of science to criminal investigation was advocated by the Austrian magistrate Hans Gross.
One of the first functional crime laboratories to be formed existed in Lyons, France, under the direction of Edmond Locard.
The first forensic laboratory in the United States was created in 1923 by the Los Angeles Police Department.
The state of California is an excellent example of a geographical area in the United States that has created a system of integrated regional and satellite laboratories.
In contrast to the United States, Britain's crime laboratory system is characterized by a national system of regional laboratories.
The increasing demand for drug analyses has been the single most important factor in the recent expansion of crime laboratory services in the United States.
Four important agencies offering forensic service at the federal level are FBI, Drug Enforcement Administration (DEA), Bureau of Alcohol, Tobacco and Firearms, and US Postal Service.
A decentralized system of crime laboratories presently exists in the United States under the auspices of various governmental agencies at the Federal, State, County, and Municipal levels of government.
The application of chemistry, physics, and geology to the identification and comparison of crime-scene evidence is the function of the physical evidence unit of a crime laboratory.
The examination of blood, hairs, fibers, and vegetative materials is conducted in the biology unit of a crime laboratory.
The examination of bullets, cartridge cases, shotgun shells, and ammunition of all types is the responsibility of the firearms unit.
The examination of body fluids and organs for drugs and poisons is a function of the toxicology unit.
The evidence collection unit dispatches trained personnel to the scene of a crime to retrieve evidence for laboratory examination.
The "general acceptance" principle, which serves as a criterion for the judicial admissibility of scientific evidence, was set forth in the case of Frye v. United States.
In the case of Daubert v. Merrell Dow Pharmaceutical, the Supreme Court ruled that in assessing the admissibility of new and unique scientific tests the trial judge did not have to rely solely on the concept of "general acceptance."
The U.S. Supreme Court decision, Kumho Tire Co., Ltd v. Carmichael, restricted the "gatekeeping" role of a trial judge only to scientific testimony. False
A Florida case that exemplifies the flexibility and wide discretion that the trial judge has in matters of scientific inquiry is Coppolino v. State.
An expert is one who can demonstrate a particular skill or has knowledge in a trade or profession that will assist the court in determining the truth of the matter at issue.
The expert witness's courtroom demeanor may play an important role in deciding what weight the court will assig to his or her testimony. True
The testimony of an expert witness incorporates his or her personal opinion relating to a matter he or she has either studied or examined. True
The ability of the investigator to recognize and collect crime-scene evidence properly is dependent on the amount of training received from the crime laboratory.
When livor mortis sets in after death, the skin will appear as a dark blue or purple color in those areas closest to the ground.
One method for approximating the time of death is determining body temperature. True

Chapter 2

The term physical evidence encompasses all objects that can establish whether a crime has been committed or can provide a link between a crime and its victim or perpetrator.
Scientific evaluation of crime-scene evidence can usually overcome the results of a poorly conducted criminal investigation. False
The techniques of physical evidence collection require a highly skilled individual who must specialize in this area of investigation. False
All unauthorized personnel must be excluded from crime scenes.
Three methods of recording the crime scene are photography, sketching, and notes.
The most important prerequisite for photographing a crime scene is to have it in an unaltered condition.
Photographs of physical evidence must include overviews as well as close-ups to record the details of objects.
An investigator need only draw a rough sketch at the crime scene to show its dimensions and pertinent objects.
A detailed search of the crime scene for physical evidence must be conducted in a systematic manner.
Besides the more obvious items of physical evidence, possible carriers of trace evidence must be collected for detailed examination in the laboratory.
In cooperation with the medical examiner or coroner, what type of evidence retrieved from a deceased victim is to be submitted to the crime laboratory? Clothing; fingernail scrapings; head and pubic hairs; blood; vaginal, anal & oral swabs; bullets; and hand swabs.
Whenever possible, trace evidence is not to be removed from the object that bears it.
Each item collected at the crime scene must be placed in a separate container.
an ordinary mailing envelope is considered to be a good general-purpose evidence container. False
An airtight container is not recommended packaging material for blood-stained garments.
As a matter of routine, all items of clothing are to be air-dried before packaging.
Charred debris recovered from the scene of an arson is best placed in a porous container. False
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 site will require the accompanying submission of control material for comparison purposes.
In the case of Mincey v. Arizona, the Supreme Court restricted the practice of conducting a warrantless search at a homicide scene.
In the case of Michigan v. Tyler, The Supreme Court dealt with search and seizure procedures at an arson or fire scene.

Chapter 3

The process of identification determines a substance's physical or chemical identity with as near absolute certainty as existing analytical techniques will permit.
The number and type of tests needed to identify a substance must be sufficient to exclude all other substances from consideration.
A comparitive analysis subjects a suspect and a control specimen to the same tests and examination for the ultimate purpose of determining whether they have a common origin.
Probability is the frequency of occurrence of an event.
Evidence that can be traced to a common source with an extremely high degree of probability is said to possess individual characteristics.
Evidence associated with a group and not a single source is said to possess class characteristics.
One of the major deficiencies of forensic science is the inability of the examiner to assign exact or approximate probability values to the comparison of most class physical evidence. True
The value of class physical evidence lies in its ability to provide corroboration of events that is as nearly as possible free of human error and bias.
The weight accorded physical evidence during a trial is left entirely to the trier of fact.
Physical evidence cannot be used to exclude or exonerate a person from suspicion of committing a crime. False
The distinction between individual and class evidence is always easy to make. False
Modern analytical techniques have become so sensitive that the forensic examiner must be aware of the natural variations that exist among materials when interpreting the significance of of comparative data.
The crime can accurately be reconstructed solely on the presence or absence of physical evidence. False

Chapter 4

A physical property describes the behavior of a substance without reference to any other substance.
A chemical property is one that describes the behavior of a substance when it reacts or combines with another substance.
The metric system of measurement was devised by the French Academy of Science in 1791.
The basic units of measurement for length, mass and volume in the metric system are the meter, gram and liter, respectively.
The centrigram is equivalent to 1/100 of a gram.
The milliliter is equivalent to 1/1000 of a liter.
0.2 grams is equivalent to 200 milligrams.
One cubic centimeter (cc) is equivalent to one milliliter.
One meter is slightly longer than a yard True.
The equivalent of one pound in grams is 453.6.
A liter is slightly larger than a quart. True
Temperature is a measure of a substance's heat intensity.
There are 180 degrees Farhenheit between the freezing and boiling points of water.
There are 100 degrees Celsius between the freezing and boiling points of water.
The amount of matter an object contains determines its mass.
The simplest type of balance for weighing is the equal-arm balance.
Mass per unit volume defines the property of density.
If an object is immersed in a liquid of greater density, it will float.
The bending of a lightwave because of a change in velocity is called refraction.
The physical property of refractive index is determined by the ratio of the velocity of light in a vacuum to light's velocity in a substance.
Solids having an orderly arrangement of their constituent atoms are crystalline.True.
Solids that have their atoms randomly arranged are said to be amorphous.
The crystal calcite has two indices of refraction. The difference between these two values is known as birefringence.
The process of separating light into its component colors or frequencies is known as dispersion.
A hard, brittle amorphous subsance composed mainly of silicon oxides is glass.
Glass that can be physically pieced together has individual characteristics.
The two most useful physical properties of glass for forensic comparisons are density and refractive index.
Comparing the relative densities of glass fragments is readily accomplished by a method known as flotation.
When glass is immersed in a liquid of similar refractive index, its Becke line will disappear, and minimum contrast between the glass and liquid will be observed.
The exact numerical density and refractive indices of glass can be correlated to frequency of occurrence in order to assess the evidential value of the comparison.
The fracture lines radiating outward from a crack in glass are known as radial fractures.
A crater-shaped hole in glass is narrower on the side where the projectile entered the glass.
It is easy to determine from the size and shape of a hole in glass whether is was made by a bullet or some other projectile. False
Stress marks on the edge of a radical crack are always perpendicular to the edge of the surface on which the impact force orginated. False
A fracture line will terminate at an existing line fracture.
The vast majority of soils have indistinguishable color and texture. False
Naturally occurring crystals commonly found in soils are minerals.
A comparison of the density of soil particles is readily accomplished through the use of density-gradient tubes.
The ultimate value of soil evidence is dependent on its variation at the crime scene. True

Chapter 5

Anything that has mass and occupies space is defined as matter
The basic building blocks of all substances are the elements
The number of elements known today is 110
An arrangement of elements by similar chemical properties is accomplished in the periodic table.
An atom is the smallest particle of an element that can exist.
Substances composed of two or more elements are called compounds.
A molecule is the smallest unit of a compound formed by the union of two or more atoms.
The physical state that retains a definite shape and volume is a solid.
A gas has no definite shape or volume.
During the process of sublimation, solids will go directly to the gaseous state, bypassing the liquid state.
The attraction forces between the molecules of a liquid are less than those in a solid.
Different phases are separated by definite visible boundaries.
Carbon-containing substances are classified as organic.
Inorganic substances encompass all non-carbon containing materials.
A qualitative analysis describes the identity of a material, and a qualitative analysis relates to a determination of the quantity of a substance.
The study of the absorption of light by chemical substances is known as spectrophotometry.
The separation of a mixture's components can be accomplished utilizing the technique of chromatography.
Henry's Law describes the distribution of a volatile chemical compound between it's liquid and gas phases. True
The higher the solubility of a gas in a liquid, the greater will be its tendency to remain dissolved in that liquid.
In order for chromatography to occur, one phase must be made to move continuously in one direction over a stationary phase. True
A technique that separates mixtures on the basis of their distribution between a stationary liquid phase and a moving gas phase is gas chromatography.
The time required for a substance to travel through the gas chromatographic column is a useful identifying characteristic known as retention time.
Solid materials that are not readily dissolved in solvents for injection into the gas chromatograph can be pyrolized into numerous gaseous products prior to entering the gas chromatograph.
A major advantage of high-performance liquid chromatography is that the entire process takes place at room temperature.
A technique that use a moving liquid phase and a stationary solid phase to separate mixtures is thin layer chromatography TLC.
Since most chemical compounds are colorless, the final step of the thin-layer development usually requires that they be visualized by spraying with a chemical reagent.
The distance a spot has traveled up a thin-layer plate can be assigned a numerical value known as the Rf value.
Thin-layer chromatography yields the positive identification of a material.False
The migration of materials along a stationary phase under the influence of an electrical potential describes the technique of electrophoresis.
Color is a usual indication that substances selectively absorb light.True
The distance between two successive identical points on a wave is known as wavelength.
Frequency and wavelength are directly proportional to one another.False
Light, X-rays, and radio waves are all members of the electromagnetic spectrum.
Red light is lower in frequency than violet light.
Light that has all its waves pulsating in unison is called a laser.
One model of light depicts it as consisting of energy particles known as photons.
The energy of a light particle (photon) is directly proportional to its frequency. True
Red light is less energetic than violet light.
The selective absorption of electromagnetic radiation by material can be used as an aid for identification.
The amount of radiation a substance will absorb is directly proportional to its concentration as defined by Beer's Law.
The spectrophotometer is the instrument used to measure and record the absorption spectrum of a chemical substance.
The function of a monochromator is to select a single frequency of light emanating from the spectrophotometer's source.
An infrared absorption spectrum provides a unique "fingerprint" of a chemical substance.
The technique of mass spectrometry exposes molecules to a beam of high-energy electrons in order to fragment them.
A mass spectrum is normally considered to be a specific means for identifying a chemical substance. True

Chapter 6

The elements of oxygen and silicon make up 75 percent of the weight of the earth's crust.
Only ten elements make up abut 99 percent of the weight of the earth's crust.
The presence of trace elements in materials provides useful "invisible" markers when comparing physical evidence.
The knowledge that elements selectively absorb and emit light provides the basis for important analytical techniques designed to detect the presence of elements in materials.
An emission spectrum is a display of colors or frequencies emitted from a light source.
A continuous spectrum consists of a blending of colors. True
A line spectrum shows distinct frequencies or wavelenghts of light.
A line spectrume of an element is characteristic of the element.
Matter in a solid or liquid state will produce and emission spectrum that is characteristic of its composition. False
The emission spectrograph is an instrument used to obtain and record the line spectrum of elements.
Excitation of a specimen can be accomplished when it is inserted between two carbon electrodes.
The selective absorption of light by atoms is the basis for a technique known as atomic absorption spectroscopy.
The composition of the discharge lamp does have to be taken into consideration when perfoming an analysis by atomic apsorption for a particular element.
One advantage of atomic absorption analysis is that it can simultaneously detect 20 to 30 elements. False
Three important subatomic particles of the atom are the proton, neutron, and electron.
The proton and electron are not of approximately equal mass.
The proton imparts the nucleus of an atom with a positive charge.
The number of protons is always equal to the number of electrons in orbit around the nucleus of the atom.
Each atom of the same element always has the same number of protons in its nucleus.
the number of protons in the nucleus of an atom is called the atomic number.
Each element has its own characteristic set of of energy levels. True
To move an electron from one energy level to the next requires a definite amount of energy. True
As an electron falls back from a higher to lower energy level, it emits light.
The total number of protons and neutrons present in a nucleus is known as the atomic mass number.
Atoms differing only in the number of neutrons present in their nuclei are called isotopes.
Deuterium has the greatest number of protons of all the isotopes of hydrogen. False
Radioactivity is composed of the following emissions: alpha rays, beta rays, and gamma rays.
Beta particles are identical to electrons.
Electromagnetic radiations similar to X-rays but of a higher energy are gamma rays.
A nuclear reactor is a source of neutrons.
The technique of bombarding specimens with neutrons and measuring the resultant gamma ray emissions is known as neutron activation analysis.
As X-rays are reflected off a material's surface, they will form a series of light and dark bands known as a diffraction pattern.
X-ray diffraction patterns are obtained from crystalline substances.

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