The Forensic Science Division of the Government Laboratory provides a wide variety of specialist scientific analytical services to the criminal justice system in Hong Kong. It is operationally divided into two groups and in 2005 a total of 437 crime scenes were attended.

The Criminalistics and Quality Management Group comprises the Biochemical Sciences A & B Sections, DNA Database and Parentage Testing Section, Chemical Sciences Section, Physical Sciences Section, and Scene of Crime and Quality Management Section. The number of cases submitted to the biochemical sections for forensic DNA analysis decreased by about 14 per cent to 4 734, from 5 547 in 2004. This has allowed resources to be diverted to developing new methodology to keep pace with world trends in the field.

The DNA Database Section regularly receives outstanding DNA profile data from the Biochemical Sciences Sections, comparing them with those in the DNA database at two levels: (a) convicted offenders' DNA profiles against outstanding profiles obtained from exhibits in unsolved cases, and (b) between pairs of outstanding profiles from unsolved cases. In 2005 there were respectively 194 and 71 pairs of matches, providing important investigative leads to the Police. The Chemical Sciences Section works mainly on cases requiring chemical analysis and investigates suspicious fires. The Physical Sciences Section plays an important role in serious traffic accident reconstruction; for instance it provided court evidence after the 2003 bus accident on Tuen Mun Highway which killed 21 people and injured 20. Apart from managing crime scene attendance, the Scene of Crime and Quality Management Section is also responsible for ensuring sustained adherence to the prescribed work standards.

The Drugs, Toxicology and Documents Group comprises the Controlled Drugs A and B Sections, Forensic Toxicology A and B Sections and the Questioned Documents Section. In 2005, cases involving heroin and ketamine continued to constitute the largest proportion of submissions to the Controlled Drugs Sections. Submissions of psychotropic substances such as amphetamine-type stimulant tablets, cannabis, midazolam and nimetazepam were also significant. However, 2005 also saw an upsurge of cases involving cocaine. The Forensic Toxicology Sections continued to improve quality and efficiency by streamlining workflow, computerisation and automation. The Urinalysis Unit, for example, developed an instrumental technique to target and identify all abused drugs including cocaine metabolites in urine samples in a single analysis to help reduce operational cost and enhance output. In addition to routine handwriting and document examinations, the Questioned Documents Section also provides consultancy and scientific testing services for Hong Kong Smart Identity Cards and Hong Kong Special Administrative Region (HKSAR) Passports.