Class Characteristics

Question 1

Physical evidence is classified into two categories:

Answer 1

• Class characteristics

* Individual characteristics

Question 2

Class characteristics:

Answer 2

• Evidence that can be compared to a group.
• This type of evidence can be used to eliminate possibilities.
• Includes size, color and manufacturing similarities.

Question 3

Class characteristics is often used as:

Answer 3

• Class characteristics is often used as a screening tool.
• If a piece of glass collected from the crime scene is compared to a known sample and fails to match the finding can be described as not being of common origin. In that case, more in depth expensive and time consuming testing would not be done. If the samples match, the finding can be described as not being excluded from being of common origin.

Question 4

Individual characteristics can be described as being “unique:”

Answer 4

• Can be linked to a specific object or person.
• Can be included or excluded as coming from an individual.
• An example of individual characteristic is the fingerprint.
• Fingerprints are natural variations in human beings.
• No two fingerprints are the same.

Question 5

When something interferes with the examination of individual characteristic evidence, it is possible to have:

Answer 5

• no conclusion result or finding.

* result is inconclusive due to insufficient details.

Question 6

Individualization is:

Answer 6

• examination of individual characteristics which is the primary
  goal of forensics.

Question 7

Typical evidence collected at crime scenes include:

Answer 7

• fingerprints, serological, biological, trace, firearms, tool marks,
  shoe and tire impression, document, general chemical and
  computer forensics.

Question 8

____________a French criminologist, is considered by many to be the father of the modern crime laboratory.

Answer 8

• Edmond Locard

Question 9

Locard’s principle of exchange states:

Answer 9

• Every contact leaves its trace.

Question 10

_______________is directly associated with Locard’s principle of exchange and is caused by inappropriate handling of evidence.

Answer 10

• Cross contamination

Question 11

____________must isolate evidence and use validated collection techniques to prevent cross-contamination problems.

Answer 11

• Crime scene technician/investigator.

Question 12

Mechanical fit or fracturing is:

Answer 12

• when an item is damaged and pieces are left at the crime scene,
  collected and preserved in the original shape and condition.
• when the source object is located and examined it maybe possible to
  learn where the piece separated from the original object.

Question 13

Fingerprints are classified using the:

Answer 13

• Henry system, developed by Sir Edward Henry in India (1894).

Question 14

Fingerprints are classified by three basic ridge patterns:

Answer 14

• Loops consists of 65% of patterns
• Whorls consists of 30% of patterns
• Arches consists of 5% of patterns

Question 15

Subdivisions of fingerprint classification include:

Answer 15

• Patterns such as plain and tented arches, ulnar,radial, double
  loops, plain, central pocket and accidental whorls.

Question 16

The majority of fingerprints found deposited in crime scenes consist of 98%_________.

Answer 16

• Water

Question 17

The remaining 2% of fingerprints deposited in crime scenes consists of:

Answer 17

• Grease, oil, salts and amino acids.

Question 18

Fingerprints can be found in three forms:

Answer 18

• Latent, patent and plastic

Question 19

______fingerprints are invisible and created by normal body secretions.

Answer 19

• Latent

Question 20

______fingerprints created by deposit of contaminants such as blood or grease visible to the naked eye.

Answer 20

• Patent

Question 21

______fingerprints are created by impressions from a soft surface such as wax.

Answer 21

• Plastic

Question 22

Patent prints can be collected by:

Answer 22

• By using photography in high resolution with a measurement
  scale in the image for reference.
• Quality of images can be improved with the use alternate light sources, chemicals and dyes.

Question 23

Latent prints can be collected by:

Answer 23

• Dusting a smooth or nonporous surface with fingerprint powder.
• Prints that appear can be photographed with and without a measurement scale and lifted with tape.

Question 24

Fingerprint powders can _____evidence and ruin the opportunity to perform other techniques that could uncover a hidden print or additional information.

Answer 24

• Contaminate

Question 25

It is a good idea to examine areas for fingerprints with________before using powders which can contaminate prints.

Answer 25

• Alternate light sources and super glue (cyanoacrylate).

Question 26

Alternate light sources laser or led emit a particular______or spectrum of light which provide a means of examining surfaces for potential evidence.

Answer 26

• Wavelength

Question 27

Cyanoacrylate (super glue) processing or fuming involves:

Answer 27

• Exposing an object or evidence to cyanoacrylate vapors which will adhere to prints allowing them to be viewed with oblique ambient light or white light sources.