INTRODUCTION: Broken glass is commonly encountered as physical evidence in crimes. Windows, automobile glass, bottles, and other glass objects may be crucial evidence in burglaries, murders, hit-and-run and many other types of crimes.
What type of evidence is glass considered?
Physical evidence is any object or material that is relevant in a crime; also known as indirect evidence. Examples are hair, fiber, fingerprints, documents, blood, soil, drugs, toolmarks, impressions, glass.
Is glass individual or class evidence?
Glass can be found as individual characteristic in cases where significant fitting of two glass fragments. However, glass is usually class evidence therefore the value of evidence will depend on the discrimination powers of techniques used for its comparison.
What is the forensic significance of glass?
Broken glass at a crime scene is a very important type of forensic evidence. Different types of glass from different sources, such as windows, bottles, or headlights, have unique chemical and physical properties that can be measured and compared.
What are the four crime scene search methods?
The basic crime scene procedures are physical evidence recognition, documentation, proper collection, packaging, preser- vation, and, finally, scene reconstruction.
What is the 3R rule for glass fractures?
The 3R rule states that Radial cracks form a Right angle on the Reverse side of the force. This rule enables an examiner to determine readily the side on which a window or pane of glass was broken.
Where is glass evidence stored?
Place small glass fragments in paper bindles, then in coin envelopes, pill boxes, or film cans which can be marked and completely sealed. Place large glass fragments in boxes. Separate individual pieces with cotton or tissue to prevent breakage and damaged edges during shipment.
Is a torn T shirt class or individual evidence?
Would this be considered class or individual evidence? Explain. This is class evidence because the ripped pieces cannot be matched to each other.
What are some examples of individual evidence?
If attempting to verify that a particular person was at a particular location, individual evidence would be best. Usually this would include some type of evidence that contains DNA. Hair root, blood, spit, etc. would all be examples of this.
Is glass direct or circumstantial evidence?
also known as direct evidence or prima facie evidence. Physical evidence is any object or material that is relevant in a crime; also known as indirect evidence. Examples are hair, fiber, fingerprints, documents, blood, soil, drugs, toolmarks, impressions, glass.
What are the 2 types of glass fractures cracks?
When a projectile i.e. a bullet or rock hits the glass, it will form two distinct types of fractures: Radial and Concentric. There is another terminology that is known as cone fracture, observed to be caused by a penetration of the high velocity projectile such as a bullet.
What techniques do you use to identify glass?
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 are the two most important physical properties of glass for forensic comparison?
To compare glass fragments, a forensic scientist evaluates two important physical properties: density and refractive index.
What is the best method for crime scene search?
The grid method is best used in large crime scenes such as fields or woods. Several searchers, or a line of them, move alongside each other from one end of the area to be searched to the other.
What are the four different search methods?
Common search patterns include the spiral, strip/line, grid, zone/quadrant, and pie/ wheel. The spiral search is used most often for outdoor crime scenes, is conducted by one person, and is done by walking in a circle from the outermost point of the inner perimeter toward the center of the circle.
What is the golden hour in forensics?
There is a golden hour at the outset where a clear head and good planning can make or break any subsequent forensic investigation. Most IT managers focus on providing their users with a good level of service and support, for example keeping the network up and running and making sure the systems are free from malware.