Ch 5

Question 1

Dna profiling

Answer 1

Each rung consists of a base pair, two of four varieties of nucleic acid, and are combined in pairs called nucleotides. The sequence of these base pairs constitutes the genetic coding of DNA.

contains the full complement of an individual’s DNA, called the genome, that is unvarying from cell to cell. The genome consists of approximately 3 billion base pairs, of which about 3 million actually differ from person to person.

Person-to-person differences within a particular segment of DNA sequence are referred to as alleles.

Question 2

Human cells contain two types of DNA…

Answer 2

Nuclear and mitochondrial

Question 3

Nuclear dna

Answer 3

contains twenty-three pairs of chromosomes in the nuclei of the cells and each parent contributes to the genetic makeup of these chromosomes.

Question 4

Mitochondria dna (mtDNA)

Answer 4

Found outside the nucleus and is inherited solely from the mother. Mitochondria are cell structures found in all human cells and they provide about 90 percent of the energy that the body needs to function.

Question 5

polymerase chain reaction (PCR) analysis

Answer 5

extracting DNA from a small evidence sample and then replicating it through a complex operation of repeated heating and cooling cycles and exposure to an enzyme.

a difference of a single allele can exclude someone as the donor of that evidence sample.

Question 6

CODIS

Answer 6

FBI is supporting this effort by linking these state databases together to form a national database known as CODIS (Combined DNA Index System).

Question 7

Latent finger prints, how many points

Answer 7

Twelve Points of Identity Indicate a Match.

Question 8

Spectrography

Answer 8

A spectrograph has a narrow slit to admit the radiation, a prism or grating to distribute the radiation, and a system of lenses to focus the wavelength pattern on a photographic plate. The pattern is recorded photographically as a series of short lines, each line being an image of the slit formed by the radiation of one wavelength. In analysis, the evidence sample is vaporized to incandescence by flame, arc, or spark and the radiation recorded.

Question 9

Chromatography

Answer 9

method of separating compounds to identify the components. Modern equipment in this area is capable of identifying compounds, such as illegal drug or poison specimens.

Question 10

X ray crystallography

Answer 10

useful for the identification of any crystalline solid or compound from which a crystalline solid derivative can be made.

Question 11

X ray diffraction

Answer 11

of use in processing very small samples, in examining samples with noncrystalline impurities, and in identifying inorganic and mineral substances.

Question 12

neutron activation analysis (NAA),

Answer 12

can analyze samples one hundred times too small for ordinary spectrographic techniques.

NAA measurements for the presence of antimony and barium, which are common gunshot residues,

Question 13

Gamma ray spectrometer

Answer 13

used to measure the distinctive radioactive gamma-ray emissions and thereby to identify the elements from which the rays originate.

Question 14

ultrasonic cavitation

Answer 14

etching method that may replace chemical, electrolytic, and magnetic particle methods of restoring obliterated serial numbers on firearms and other metal objects.

Question 15

trace metal detection technique (TMDT)

Answer 15

Distinctive “signatures” of handguns, tools, and other metal objects are now available to investigators through an innovative trace metal detection technique (TMDT), which makes the patterns of these objects visible on the skin or clothing of suspects when treated with a test solution and examined under ultraviolet light

Question 16

Voiceprinting

Answer 16

based on the physical characteristics of each individual’s vocal cavities (the throat, mouth, nose, and sinuses) and the manner of manipulating the lips, teeth, tongue, soft palate, and jaw muscles. It is a technique of personal identification that may challenge fingerprints as the most positive means of personal identification.

applicable to the identification of voices involved in kidnappings, obscene language telephone calls, and telephoned threats.

Question 17

National Integrated Ballistic Information Network (NIBIN)

Answer 17

there is a database of fired cartridge casings and bullet images used by crime laboratories. This system links firearms evidence including fired bullets, cartridge casings, shotgun shells, and recovered firearms by means of a microscope attached to a computer. The evidence is electronically scanned and stored for retrieval and comparison with other images. The system has the ability to compare images with regional and national databases.

Question 18

International Forensic Automotive Paint Data Query (PDQ)

Answer 18

database developed and maintained by the Forensic Laboratory Services of the Royal Canadian Mounted Police. The database contains chemical and color information pertaining to original (factory) automotive paint, and can determine the make, model year, and assembly plant on more than 13,000 vehicles.

Question 19

substitution cipher

Answer 19

The most common cipher in use by criminals is a simple substitution cipher in which a symbol, letter, or digit stands for another symbol, letter, or digit.

Question 20

Transposition ciphers

Answer 20

characterized by a change in the order of the enciphered material. Investigators find it fairly common in recording telephone numbers. This may be a reversal transposition in which the telephone number 445-1769 becomes 967- 1544, or any split combination, for example, 176-4459, 769-4451, and 544-1769.

Question 21

Shoe print Image Capture and Retrieval (SICAR)

Answer 21

Crime scene shoe prints can be entered into the system by scanner or digital picture.