What is Forensic Chemistry?

... the science dealing with the application of chemical knowledge to legal questions.

 
   
Blood tests

There are a great number of tests possible to identify the exact blood type (e.g. ABO , Rh +/-) and tests of different enzyme systems (erythrocyte acid phosphatase, esterase, glycosidase...etc.). They are always applied in disputes on the fatherhood of a child but only seldom in other cases. Their use in crime investigations depends on how many and what other traces the police has. If they need proof, the police can demand such a test. Blood tests are not incontestable as the DNA profile but can exclude some of the suspects.

DNA analysis are still rather expensive and are only required in very tough cases.

 
   
Fingerprints

The ridges on the tips of the fingers and thumbs are useful as a means of identification because no two persons have the same pattern of ridges.

"Dactyloscopy", the technique of fingerprinting, involves cleaning the fingers in ether, drying them, then rolling the tips of each over a glass surface coated with printer's ink. Each finger is then carefully rolled on prepared cards according to an exact technique designed to obtain a light grey impression with clear spaces showing between each ridge so that the ridges may be counted and traced. Modern computer systems allow the evaluation of huge number of fingerprints from databases in short periods of time.

 
 
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