Quick Answer: What two properties of glass fragments must a forensic scientist evaluate?

What are the two most often used methods of glass analysis?

The flotation and immersion methods are best used to determine a glass fragment’s density and refractive index, respectively. The latter involves immersing a glass particle in a liquid medium whose refractive index is verified unit it is equal to that of glass particle.

What can a forensic technician examine glass fragments for?

If a window or glass object is broken or shattered by a projectile, such as a bullet, the breakage pattern can be analyzed to possibly determine the angle of trajectory of the projectile, shedding more light on the crime, such as where the suspect was when the gun was fired.

What evidence can be found on glass fragments?

Trace evidence can be found at a crime scene in a number of different forms, including hairs and fibers, glass, or soil. Glass analysis includes determining the type of glass based on glass fragments. However, the entire fractured pane or window can be helpful when determining direction and sequence of force.

THIS IS IMPORTANT:  Your question: How has psychology affected criminology?

What must a forensic scientist do to confirm that a sample piece of glass is from the same original piece of glass?

Comparing the color of a suspect piece of glass with the color of a reference sample can distinguish whether the two samples share a common source. As a consequence, significant color differences between glass fragments can be used as the basis for exclusion of a suspect.

What are the two most important physical properties of glass for forensic comparisons?

To compare glass fragments, a forensic scientist evaluates two important physical properties: density and refractive index.

What is glass analysis in forensic science?

Analysis. A forensic glass analysis is typically a comparison of two or more glass fragments in an attempt to determine if they originated from different sources. Less frequently, it is a question of determination of end use, or glass provenance.

What are two ways the atomic composition of a glass fragment may be determined?

You can use scanning electron microscopy, X-ray fluorescence spectrometry, inductively coupled plasma-optimal emission spectrophotometry, inductively coupled plasma-mass spectrometry, laser ablation-inductively coupled plasma-mass spectrometry, or atomic absorption spectrophotometry.

What characteristic of glass is used to help determine its source of origin?

In addition to matching density, physical matches can also help forensic scientists determine if a piece of glass came from a crime scene. Due to the random nature of breaking or tearing, a questioned or un- known piece can be identified as coming from a known source.

What are the properties of glass?

The main characteristics of glass are transparency, heat resistance, pressure and breakage resistance and chemical resistance. The surface of glass is affected if it is exposed for a long time to alkalis (and ammonia gases in damp air) in conjunction with high temperatures.

THIS IS IMPORTANT:  Who hires forensic entomologists?

How might a forensic scientist tell which of two fractures on a piece of glass was invented earlier?

How might a forensic scientist tell which of two fractures on a piece of glass was created earlier? They can observe the fracture lines and their points of termination.

What two tests can be done to determine the identity of a type of glass?

Glass: Glass can yield valuable information through fracture marks, lines and patterns. Testing for unique characteristics such as color, optical properties and density can determine the type of glass, for example a window pane, vase or glass bottle.