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Resurrecting Fingerprints

Resurrecting Fingerprints

A new breakthrough in forensic science appears to have found the solution to this problem. Fingerprints are often the key to solving crime mysteries.

However, the problem arises when the criminal wipes out fingerprints from bullets and leaves no trace of his identity, making it difficult to solve the case. A new breakthrough in forensic science appears to have found the solution to this problem.

British scientists headed by Dr. John Bond have discovered a new technique that enables them to lift fingerprints from bullets – even when they have been wiped clean.  Their study is published in the Journal of Applied Physics and the Journal of Forensic Sciences.  British and American investigators employed this technique as they reopened three cold cases.  This new technique has made investigators optimistic that the criminal cases, which includes a double murder case, can now be solved.  In one of the three cases, investigators were able to gather enough evidence that can help them identify the criminal.

So how does the technique work?  The traditional way of lifting fingerprints is an old method that has existed for over 100 years.  Basically, when a person touches an object, his or her sweat sticks to the object and makes a fingerprint impression.  The investigators use certain chemicals to react with this sweat in order to produce a fingerprint image.  Wiping off the sweat makes it almost impossible to get a fingerprint image.

The technique developed by John Bond and colleagues enables them to get a fingerprint even in the absence of sweat impression.  It makes use of traces of corrosion left by sweat upon reacting with metals such as those found in bullets and bombs.  The researchers covered the metal with a certain kind of powder and applied 2500 volts of electricity, which caused the powder to adhere to the corroded parts of the metal.  A fingerprint mark was then produced.  Although the technique has limitations, such as for people whose sweat does not contain enough salt to corrode metal, it is one step closer to solving cold cases.