This report provides a detailed examination of human DNA in drugs and the feasibility of extracting from it information useful for policing.
The expected outcomes of the project were to:
• identify how frequently drugs contain human DNA;
• assess the relative merits of various methods for profiling this DNA and make recommendations on which to use; and
• establish the conditions under which DNA survives in drug powders.
The project achieved these outcomes and made some new fundamental findings.
A key finding is that most seizures contain at least a trace of human DNA—in fact it is uncommon for a seizure to be free of human DNA. However, we did not observe any seizures that contained DNA from only a single human. The study also demonstrated that the current standard forensic short tandem repeat (STR) DNA profiling technique, Profiler Plustm, is impracticable as a routine operational screening method for illicit drug powders when a mixture of donors exists. These findings led to trialling alternative methodologies.