DNA Identification of Biological Traces on Cigarettes: Vices Reveal

ABSTRACT

Isolation of cell material from biological traces on forensic evidence is often a serious challenge to solving forensic cases. Successful isolation of high-grade DNA from cell material even in critically low quantity could be achieved in examination of traces which are more than two years old.

We present two cases representative of a group of 28 cases with cigarette butts that were from 10 days to 2 years old. The proper collecting and storage of the material is very important for successful DNA typing from saliva traces and epithelial cells from the lips and oral cavity. Meeting these conditions would increase the chances for successful DNA profiling of biological traces on evidence of an earlier date.

The result of our examination confirms the importance of the worldwide accepted approach for setting up a database of DNA profiles. In the presented forensic cases the opportunity for solving the crime was given by the vices of the suspects.

Keywords:

• forensic evidence
• DNA typing
• cigarette butts
• STR
• Y chromosome
• interpretation