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GullSO Invitational — Forensics

Forensics · Division C · GullSO Invitational · 2024

36 questions · 60 points · 50 min· 7 questions from the original omitted

Original test source

You have 50 minutes to complete this exam, plus an extra 5-minute grace period at the end to organize your pages for submission. You will not be allowed to write anything during the grace period. You can take the test booklet apart (but you MUST put it back in order at the end). Within each section, short answer questions are worth 2 points, true-false/multiple choice questions are worth 1 point, and calculations are worth 3 points. Sections are weighted according to the rules. Tiebreaker questions are labeled with “TB” next to the point value. Write your answers on the provided answer sheet ONLY.

Powders

FigureFor questions 1–5

The following powders were all found at the crime scene. Name each powder, how you identified it, and the suspect(s) implicated.

Question 1

1 pt

Powder #1: Name of powder; Identifying property; Suspect(s) implicated

Question 2

1 pt

Powder #2: Name of powder; Identifying property; Suspect(s) implicated

Question 3

1 pt

Powder #3: Name of powder; Identifying property; Suspect(s) implicated

Question 4

1 pt

Powder #4: Name of powder; Identifying property; Suspect(s) implicated

Question 5

1 pt

Powder #5: Name of powder; Identifying property; Suspect(s) implicated

Hair & Fibers

Question 1

2 pts

During which phase of hair growth is blood supply stopped and there are no new hair-growing cells?

Question 2

2 pts

Unknown fiber #3 was found at the scene. When burned, it burns at a constant rate, produces no smoke, and smells like grass. ID this fiber.

Question 3

2 pts

What type of DNA is found in the root tissue of hair?

Question 4

2 pts

Unknown hair #2 was found at the scene, but only the shaft was collected. If there is no root tissue present, what type of DNA can be analyzed to ID whose hair it is?

Question 5a

2 pts

Humans have a medullary index of ____. HINT: Give your answer as a number.

Question 5b

2 pts

Animals have a medullary index of ____. HINT: Give your answer as a number.

PassageFor questions 6a, 6b

Unknown fiber #1 is typically processed with NaOH through mercerization: a process of drying the walls of the fiber to collapse the central lumen.

Question 6a

2 pts

ID this fiber.

Question 6b

2 pts

Describe why mercerization is used (2 reasons).

Glass Analysis

Question 1

2 pts

Snell's law of refraction describes the relationship of light waves as it passes through the interface of two isotropic media. Write the formula for Snell's law.

FigureFor questions 2a, 2b

Glass Analysis: Image 1 shows the fracture pattern left on the window of a subway car.

Question 2a

2 pts

Identify the type of fracture of A.

Question 2b

2 pts

Glass Analysis: Image 1 shows the fracture pattern left on the window of a subway car. Identify the type of fracture of B.

Question 3

1 pt

What has the greatest refractive index among the following substances?

Question 4

1 pt

In the formula for refractive index n = c/v, the variable c stands for which of the following?

Fingerprints

Question 1

2 pts

What does AFIS stand for?

Question 2

2 pts

Unknown fingerprint #4 was lifted from glass using cyanoacrylate (superglue) fuming. Describe this process.

Question 3

2 pts

ID Fingerprint #2.

Question 5

2 pts

ID Fingerprint #3.

Question 6

1 pt

TRUE OR FALSE: Twins can have the same fingerprints.

Question 7a

2 pts

Ninhydrin reacts with ____ in sweat, producing a ____ color print. (first blank)

Question 7b

2 pts

Ninhydrin reacts with ____ in sweat, producing a ____ color print. (second blank)

Entomology & Time of Death

Question 1

1 pt

What insect typically arrives first to the scene of a dead body?

Question 2

1 pt

At this stage of mortis, blood settles to the lower portion of the body, creating red discoloration in the skin.

Question 3

3 pts

Average body temperature is 98.6 degrees F. The body temperature of a corpse is found to be 67 degrees F. Approximately how many hours has the body been dead? Round to the nearest whole number and show your work.

Blood & DNA

Question 2

1 pt

The velocity of the blood spatter seen in unknown blood #3 can be approximately gagged as

Question 3

2 pts

____ detects presence of iron in hemoglobin, visualizing blood stains with a blue fluorescence.

Question 4

1 pt

Blood droplets with a smooth edge seen in blood: image #1 was most likely dropped on which type of surface?

Question 5

1 pt

Which of the following describes the blood spatter pattern scene in unknown blood #4?

Question 6

1 pt

Unknown blood #1's antigen's test shows which of the following blood types?

Question 7

3 pts

The width of the blood spatter found is 5 cm wide and 11 cm long. What is the angle of incidence to the nearest hundredth? Show your work.

Question 8

2 pts

How many copies of DNA are made after 5 cycles of PCR? Show your work.

Question 9

2 pts

Describe erythroblastosis fetalis.