Stainless steel handle fingerprint extraction

2013-07-10 15:07:54

City of Hubei Province Public Security Bureau of Criminal Investigation Brigade Ma (431600) Mei Honghui

In recent years, the authors survey the scene thefts, often encountered in metal cabinets or safes fingerprints on stainless steel handle difficult extraction problem. Direct photographs, easy to form due to reflective spot; and handle conical or irregular in shape, shoot fingerprints is deformed, can not be compared on the identification of the author in the crime scene during groped one kind of simple extraction method. Are presented below:

A method

Appropriate size paper clip, the "502" solution evenly on the filter until the filter surface is slightly dry, the coating solution is gently around the side of the handle around with tape adhered thereto. In the case of high temperature, just 3 min-5 min, then uncover the paper, show the effect observed. If the apparent lack of fingerprints weak contrast, may be extended smoked present time.

Fingerprints appear to be after the transparent tape along with a wide perimeter around the handle, push hard, sticky fingerprints will be taken down, attached to the black paper, photographic fixed.

2 Precautions

Do not use alkali fuming heating or other apparent acceleration method, transparent adhesive tape to prevent damage when taken ridge characteristics.

This method should be thicker fuming fingerprints, so stick better, while a sticky fingerprints can be taken several times.

Sticky paper tape immediately after taking photographic fixation. For "502" adhesive a-cyano acrylate in water and acid initiator, the polymerization takes place, into a solid polymer, adhesive tape such polymers formed by the extraction means stamped line, the polymerization material and prone to physical and chemical changes in the characteristics of affected whipped, and even ridge disappears.

Arc-shaped door handle on the ball suddenly this method can also be used to extract fingerprints. But when you take note affixed along the direction of the arc-shaped with a narrow tape overlap extraction, or narrow tape vertical extraction, depending on different forms depending on the handle.

Disadvantages: The entire operation is not easy to take the tape to grasp, easy to form a bubble, affecting photographic effect. The tape must be a fingerprint special tape,

LoginName:
Password:
Verification: