The spectroscopic detection of drugs of abuse on textile fibres after recovery with adhesive lifters.

ABSTRACT

Fibres are one of the most common forms of evidence associated with forensic investigations. The use of adhesive lifters to recover fibres from crime scene samples has long been established as an effective method to recover such items of evidence. Once fibres have been lifted they are transferred to evidence bags for storage, safe transport and to preserve the chain of evidence. This study shows that when fibres are tape lifted particles of substances present trapped within those fibres are also lifted. Cotton, linen and wool fibres were examined in colours ranging from white to black. Samples of seized ecstasy, cocaine, ketamine and amphetamine were supplied by East Sussex Police and by the TICTAC unit at St Georges Hospital Tooting. The Raman spectra obtained showed that it is possible to identify drugs of abuse from particles trapped within fibres without interference from the fibre itself. It was also possible to obtain spectra after fibres were lifted with adhesive tapes without the detection process being compromised. Raman spectra from particles of drugs of abuse within fibres following tape lifting were also recorded through evidence bags. Again the detection process was not compromised. This initial study has shown that fibres have the potential to provide even more evidence than they do currently. Individuals that have had drugs of abuse about their person may have trace amounts of these substances trapped within the fibres of their clothing. This may be of particular importance if drugs have been carried in pockets of a garment. This technique has the advantage of being non-destructive, allows for re-testing, requires no sample preparation and also can be performed on samples without removal from the evidence bag thus removing any potential risk of contamination. It is important however to remember that when dealing with trace amounts of drugs of abuse the presence of such particles may be due to innocent transfer of such particles. Detection of particles of drugs of abuse on clothing does not necessarily indicate criminal activity in the absence of other evidence.