Automatic powder supply trace detection equipment and powder supply method for extracting fingerprints by powder method at crime scene

Abstract

An automatic powder supply and trace detection device for extracting fingerprints by means of crime scene powder method and powder supply method thereof; an air pump (3) is in electrical communication with a battery (1), and an air outlet end of the air pump (3) is in communication with a powder bottle (7); an ultra-microporous fluidised bed (10) is installed inside the powder bottle (7), the trace detection powder in the powder bottle (7) being accommodated above the ultra-microporous fluidised bed (10); pressurised air outputted by the air pump (3) passes through the ultra-microporous fluidised bed (10) from below the ultra-microporous fluidised bed (10), forming a plurality of independent air streams acting on the bottom of the trace powder, and producing a mixed gas on the surface of the trace detection powder; one end of an outer shell (22) is provided with a nozzle (20) having a nozzle opening, and a brush head (13) surrounds the nozzle opening, a mixed gas pipe (8) being hermetically connected to the nozzle opening being arranged inside the powder bottle (7), the mixed gas produced in the powder bottle (7) being conveyed to the brush head (13) of the nozzle opening by means of the mixed gas pipe (8), and the trace detection powder in the mixed gas coming into contact with a fingerprint trace and attaching to the surface of the fingerprint trace to form a clear image. The automatic powder supply and trace detection device improves the working environment of police officers, reduces the amount of powder used, and increases the efficiency of sampling work.

Description

technical field [0001] The invention belongs to a trace detection tool in the field of public security criminal investigation, in particular to an automatic powder trace detection device and a powder supply method for extracting fingerprints by powder method at a crime scene. Background technique [0002] Currently, the most common method used for crime scene fingerprint imaging and analysis is called powder phenotype, which is often seen in movies or television. Investigators brush the fine powder on the fingerprints, and then paste scotch tape to obtain the shape and traces of the powder (actually the traces of the fingerprints); in this way, the investigators can save the fingerprint information on the tape, which is convenient for taking back to the laboratory for in-depth analysis. If fingerprints remain on the surface of non-absorbent items such as metal, plastic, glass, and tiles, you can use the powder method to extract fingerprints. Use a soft brush to dip a little...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the above-mentioned problems caused by the powder suspended in the air in the existing powder visualization method, the object of the present invention is to provide an automatic powder supply trace inspection device and a powder supply method for extracting fingerprints by powder method at the crime scene

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