To look at, you'd say Patrick Cheng Yau-sang is a neat man. His desk suggests otherwise. It is cluttered with sheets of paper and equipment: a stereo microscope imported from Germany, a hand-held microscope, a protractor, a torch and a light box.
On closer inspection, it becomes apparent the sheets of paper all bear signatures, which are awaiting Cheng's scrutiny. The 56-year-old Tuen Mun resident is a forensic handwriting examiner and it's his job to ascertain whether these signatures are genuine or forgeries.
Forensic science - encompassing everything from anthropology and psychology to DNA evidence and bloodstain-pattern analysis - has become an integral part of solving crime.
Cheng's work is usually carried out away from the public gaze but a recent high-profile case thrust him, and his particular brand of science, into the limelight.
The case involved Asia's richest woman, Nina Wang Kung Yu-sum, and her 94-year-old father-in-law, Wang Din-shin. In a legal battle that stretched over eight years, the two fought over the $27 billion Chinachem Group, which had belonged to Nina's late husband, Teddy Wang Teh-huei. Wang senior claimed Nina had forged Teddy's will, which superseded one made in 1968 naming him as beneficiary.
Looking around Cheng's modest home office, one would never guess he played a vital role in one of the biggest and most expensive cases in Hong Kong's legal history. Although handwriting and document experts were brought in from the US, Canada and the mainland to give evidence, Hong Kong had one of the best authorities on the subject in residence.
'The Nina Wang case started in 1989. I was working for the Commercial Crime Bureau when the senior Wang called the cops about suspected forgery. I was the section head of the questioned-documents section of the government lab when the case went to court in 2002.