Forensic Science Division

Physical Sciences Section

The Physical Sciences Section provides a wide range of service to government departments in the areas of physical examination including traffic accident reconstruction, tyre examination, vehicle number restoration, forgery and counterfeit items, forensic video analysis and cases involving toolmarks and shoeprints.

Analysis of shoeprint

Analysis of shoeprint

Traffic accident reconstruction (TAR) involves the application of various scientific disciplines including mathematics, physics, automotive engineering and scene investigation techniques in deciphering possible cause of road traffic accidents. The forensic examination of failed tyres often provides useful information in determining whether their deflation causes the accident or is a result of the impact in the accident. Vehicle number examination and restoration entails, as the name suggests, the discovery and retrieval of numbers unique to the vehicles concerned as a means of detecting unauthorised vehicle-taking or modification. Forgery and counterfeit items such as precious metals, gems and Hong Kong circulation coins are investigated using state-of-art instruments. Forensic video analysis (FVA) applies advanced video analysis software and image processing software to extract relevant information from still images and video footage recorded by security cameras, vehicle cameras and mobile phones pertaining to criminal cases and major incidents. The section also deals with a large number of theft-related cases involving the preservation or matching of toolmark and/or shoeprint exhibits.

The Physical Sciences Section offers professional advisory services to Hong Kong Police Force and other government departments pertaining to traffic accident investigation. The objective of this service is to provide impartial expert opinion for court proceedings. This section also organizes training courses on forensic traffic accident investigation and reconstruction to the law enforcement agencies. The participants of these courses will learn about the latest development in the field of traffic accident reconstruction.

Traffic accident reconstruction

Traffic accident reconstruction

Key Instruments

The following instruments are used routinely by the Section:

  • Comparison microscope
  • X-ray fluorescence spectrophotometer
Comparison microscope

Comparison microscope

X-ray fluorescence spectrophotometer

X-ray fluorescence spectrophotometer

Targets and Key Indicators

Key Performance Measures Relating to the Forensic Science Services

Targets

Target is defined as the percentage of completed cases whose individual case-completion time does not exceed a specified number of working day(s).

Targets 2020 (Actual) 2021 (Actual) 2022 (Plan)
90 78 77 90

Targets 2020 (Actual) 2021 (Actual) 2022 (Plan)
90 N.A. 58 90

Ψ The performance has been affected by the growing demand on video/image analysis, a category of work that the Laboratory introduced since 2019.

Ω New target as from 2021.

Key Indicators
Number of Cases Investigated 2020 (Actual) 2021 (Actual) 2022 (Estimate)
Physical sciences 725 755 800