Biomedical subjects

Asne Klein

Publications and source records attributed to Asne Klein.

4 recordsLinked to original sources

PubMed2005

A field diagnostic test for the improvised explosive urea nitrate.

A sensitive, specific and simple color test for the improvised explosive urea nitrate is described. It is based on the formation of a red pigment upon the reaction between urea nitrate and p-dimethylaminocinnamaldehyde (p-DMAC) under neutral conditions. Urea itself, which is the starting material for urea nitrate, does not react with p-DMAC under the same conditions. Other potential sources of false positive response e.g., common fertilizers, medications containing the urea moiety and various amines, do not produce the red pigment with p-DMAC. Exhibits collected from 10 terrorist cases have been tested with p-DMAC. The results were in full agreement with those obtained by instrumental techniques including GC/MS, XRD and IR.

Colorimetry↗

PubMed2003

Deciphering indented impressions on plastic.

The questioned document laboratory is often called upon to decipher writing that has been erased, obliterated, or that has faded. In cases like these, the original writing is no longer legible to the naked eye, but may be enhanced using various light sources. Certain remnants of the ink's components absorb into the substrate's fibers and can be visualized, usually as luminescence or absorbance. A case is described here that involved the theft of a credit card. An empty plastic credit card holder was found in the possession of a suspect, and as submitted for examination. Indented impressions could be discerned on its clear plastic window and presumably originated from the credit card that had been held in the envelope. These indented impressions were deciphered in the hope that they would reveal enough details from the credit card to establish a connection between the plastic envelope and the stolen credit card. With methods generally utilized in the toolmarks and materials laboratory and the photography laboratory of the Israel Police, most of the indented impressions on the plastic were deciphered and a connection between the plastic envelope and the stolen credit card was demonstrated.

Journal Article↗

PubMed2002

Unusual contact marks: connecting the hubcap to the wheel of the car.

A case of homicide and attempted homicide is described. The comparison of tire-marks linked the suspect's vehicle to the scene of crime only with low certainty. However, the comparison of the pressure mark on the hubcap found at the scene, with the balance weight on one of the wheels of the suspect's car, connected the suspect to the scene of crime with high certainty.

Journal Article↗

PubMed2002

The identification of stolen paintings using comparison of various marks.

Several oil paintings, suspected of being stolen, were found in the possession of an art dealer in Tel-Aviv, Israel. The authors were asked to determine if these paintings were the stolen ones, based on photographs, stretchers, and frames submitted by the alleged owners in France. A physical match was found between two of the questioned paintings and two stretchers. Another painting was identified as being previously affixed to the original frame by several nails. The fourth painting was identified as being the one photographed by the alleged owner. This identification was done by comparing micro-topography marks revealed by the illumination conditions of that photograph and of the questioned painting.

Journal Article↗