Technical note: Reliability of police-recorded drug offence codes as a measure of drug types

08 July 2016

This short paper examines the reliability of police-recorded drug offence code in determining the types of drugs involved in drug offences. The project assessed this reliability by comparing offence records recorded by police with a sample of Victoria Police forensic drug test results for those offences. This technical note is intended to provide context for interpreting the results of CSA data and analyses that provide information on the types od drugs involved in drug offences.

Key findings  

• Overall, for 78% of the drug offences in the sample, police correctly identified the drug type at the time of recording the offence. 
• The rate of correct identification of drug types was higher for cultivate/manufacture drug offences (94% correct), followed by dealing/trafficking offences (84% correct), followed by use/possession offences (70% correct). 
• Of the 136 police-recorded methamphetamine offences included in the sample, 121 (89%) had a positive test result for methamphetamine, with 105 (77%) were for the crystal form of methamphetamine.