Forensic expert used photogrammetry to find out the size of objects in picture, it was revealed in the Coroner's Court yesterday.

The technique involved measuring the permanent installation, such as pillar of buildings, before estimating the size of the target object, forensic scientist Wong Tai-wai testified.

Wong estimated the suspect of the Hang Seng Bank robbery in 2001 was 176 centimeters tall with 9cm error after measuring the size of the bank's barrier and rubbish bin, which were 90cm and 60cm tall respectively.

The man in the video seized from dead constable Tsui Po-ko's home in Tung Chung was estimated to be 181cm tall with 7cm error after measuring the size of the pillar of the Citygate shopping mall, where the video was taken.

Wong testified that if the suspected robber was 177cm tall without wearing shoes, it would be consistent with his finding.

He also believed that the robber wore a black hood.

Cheung also testified that the service revolver found in the Tsim Sha Tsui shoot-out scene last year had a serial number of RHKP 7215 and the gun used by the constable, Leung Shing-yang also had the same serial number.

The barrel of the revolver had the name of the manufacturer Smith and Wesson written on it.

Wong had also examined the shoe prints given by the police.