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: the Criminalistics and Quality Management Group and the Drugs, Toxicology and Documents Group. The Drugs, Toxicology and Documents Group comprises five sections — the Controlled Drugs A and B Sections, the Forensic Toxicology A and B Sections, and the Questioned Documents Section.

In 2004, cases involving heroin and ketamine continued to constitute the largest proportion of submissions to the Controlled Drugs Sections. Psychotropic substances such as amphetamine-type stimulant tablets, cannabis, midazolam and nimetazepam for analysis were also significant. While case types and inputs were similar to the previous year, the Forensic Toxicology Sections improved on the quality of service through extensive computerisation and re-engineering of methodology.

Significant improvements were achieved in case output and turnaround time in the two main services, analytic toxicology and urinalysis after the implementation of the new work procedures. In addition to routine handwriting and document examinations, the Questioned Documents Section also provides consultancy and scientific testing services in respect of Hong Kong Smart Identity Cards and Hong Kong SAR Passports.

The Criminalistics and Quality Management Group carries out various types of laboratory analysis and conducts crime scene examinations. A total of 628 scenes were attended in 2004. The number of cases submitted to the Group's Biochemical Sciences A & B Sections for forensic DNA analysis increased sharply from 4 214 in 2003 to 4 846 in 2004. The DNA Database Section regularly receives outstanding DNA profile data from the Biochemical Sciences Sections, and compares 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 outstanding profiles from unsolved cases. In 2004 there were respectively 159 and 100 pairs of matches, providing important investigative leads to the Police Force.

The Parentage Testing Section handles cases relating to Right of Abode applications; the Chemical Sciences Section works mainly on cases requiring chemical analysis and investigates suspicious fires; while the Physical Sciences Section plays an important role in serious traffic accident reconstruction. Apart from managing crime scene attendance, the Scene of Crime and Quality Management Section is responsible for ensuring sustained adherence to the prescribed work standard.