Expert Solutions
Glass and Paint

Collecting and examining glass and paint particles are often useful in cases of burglary, criminal damage and theft, and include attacks on vehicles, and domestic and commercial premises. A glass examination can also help to establish that a person was inside a vehicle at the time it crashed, demonstrate that an implement has been used to break glass, or determine from which side a window has been broken.

Our scientists can examine items and recover glass fragments a fraction of a millilitre in size, and determine their properties to enable comparison with a crime scene sample. The presence of matching glass can provide very strong supporting evidence, and likewise the absence of glass in certain circumstances can provide evidence to support a person not being involved in an incident.

The laboratory work involves the gathering and collection of minute particles. For example, a garment and any pockets will be swept separately for traces and the material collected examined under a microscope. Where glass particles are concerned, the Glass Refractive Index Measurement (GRIM) tool assists in the identification process, while for paint and other substances, chemical tests and high-powered microscopy will be used.

FSS keeps abreast of the huge variety of glass, paints, tints and coatings on the market, detailing their physical and chemical properties and their applications to ensure its forensic research capabilities remain comprehensive and fully up-to-date. Databases are maintained for specific items such as glass and vehicle paint, together with physical samples to demonstrate refractive indices and chemical compositions.