Using the techniques offered by a microscope for the purposes of criminal or civil law officially dates back to Edmond Locard (1877–1966), who stated that every contact leaves a trace. This is known as the Locard exchange principle, which forms the bulwark of modern forensic microscopy. The microscope remains one of the most respected and utilized tools in the crime laboratory. Criminal evidence ranging from micrometer-sized particles to hair and paint chips can be found and analyzed, and microscopy can provide important insights into the identity and origin of any material found at a crime scene.
Russian criminal investigators are now using new stereomicroscopes with digital recording systems more and more frequently. These stereomicroscopes incorporate a special lighting system, which consists of a circular light source, and an optical circuit for the investigation of a myriad of crime-related evidence, including documents and banknotes. The lighting system provides the illumination of the surface of objects without shadows and in different directions and from diverse angles.
Stereomicroscopes are also known as dissecting microscopes and they are in reality two compound microscopes, which focus on the same point from slightly different angles. The benefit of this is a three-dimensional view of the specimen in question and an upright and laterally correct image (not upside down and backwards). These microscopes are much lower in power than compound microscopes (usually below 100x), and there are three magnification modes available; single fixed, several discrete or a zoom system.
Stereomicroscopes provide a much longer working distance as well, and the nickname ‘dissecting microscope’ comes from the fact that these scopes allow work to be done on the specimen while it is being observed through the microscope. Many stereomicroscopes are very versatile and they have interchangeable parts, which permit a myriad of varieties in stands, eyepieces, objectives, and lighting techniques.
If you are thinking of committing a crime, I would say stop and don’t do it, for it is just a matter of time before the stereomicroscope catches up with whatever you may leave behind!