The detection and taking of fingerprints with the subsequent identification of the person on them constitute a separate branch of forensic research, called fingerprinting. The identification of traces at the scene of the incident allows you to accurately identify the person who left the prints, which contributes to the disclosure of crimes. Various methods are used to detect fingerprints.
Necessary
- - oblique lighting source;
- - special aerosol.
Instructions
Step 1
Use oblique lighting to reveal fingerprints on smooth surfaces. Direct a beam of light at a specific angle at an object or surface. In this case, fingerprints, if any on the surface, will be clearly visible. A prerequisite for such a study is not to leave your prints on the subject, which can blur the existing picture. In this way, it is convenient to detect marks on furniture, polished or varnished surfaces of products, for example, on household appliances.
Step 2
If you need to find fingerprints on ceramic or glassware, then use the same method, but you can do without an artificial light source. Gently grab the object by the edges and bring it to the lighted window. In clear weather, the sun's rays falling at an angle to the surface of the glass will replace the light of the lamp.
Step 3
For detecting and fixing fingerprints on wet surfaces, use special products such as “SPR” spray. It is a special solution that allows you to identify fingerprints on a damp, non-porous surface. This method is more convenient than the powder method used in forensic science.
Step 4
Shake the aerosol can. Then spray the product evenly over the vertical surface you expect to find fingerprints on. Use a balloon from a distance of 20-30 cm. After a few seconds, the desired prints will appear on the place that has been treated with the composition.
Step 5
Wait until the composition is completely dry, after which the prints can be separated and saved for later examination. If possible, first photograph the developed traces before removing them from the surface.
Step 6
Use an aerosol to take fingerprints exactly from a vertical surface, since liquid does not spread on horizontally placed objects, but is located in one place, which makes it difficult to detect fingerprints.
