Glass Forensics

Hair, fiber, fingerprints, document, blood, tool marks, impressions and glass are examples of what type of evidence?

• direct evidence

• physical evidence

• indirect evidence

• circumstantial evidence

Two methods that can analyze fibers without damaging them are _____.

• polarizing light microscopy & infrared spectroscopy

• polarizing light spectroscopy & infrared microscopy

• heat and light

• none of these

When the refractive index of the liquid matches the refractive index of the glass fragment; this is called the ___________________________________.

• match point

• immersion line

• Becke line

A high velocity projectile always leaves a hole wider at the ________________________side of the glass.

• entrance

• exit

• middle

Glass samples collected should be documented, marked (if necessary), packaged, and labeled. When the samples are collected the samples must be placed in __________________.

• metal paint can

• manila envelop

• zip lock bag

What type of fracture is this?

• Becke

• Conchodial

• Concentric

• Radial

What will NOT be visible if a glass and a liquid has the same refractive index?

• Conchoidal Lines

• Becke Lines

• Fracture Lines

• Radial Lines

What is the 1st step for handling glass at a crime scene?

• Identify and photograph any glass samples before moving them. 

• Collect the largest fragments that can be reasonably collected

• Identify the outside and inside surface of any glass

• If multiple panes are involved, make a diagram

What type of evidence is glass considered in forensic science?

• Direct evidence

• Physical evidence

• Indirect evidence

• Circumstantial evidence

Which method can analyze glass without damaging it?

• Polarizing light microscopy

• Infrared spectroscopy

• Heat and light

• None of these

Tags

NGSS.HS-PS4-5