Can you recognise the face of a suspect after having merely a glance at his photo? Sergeant Poon Yiu-fai proved that a professional police officer could do so. His alertness has landed a wanted man in jail.

Last August, the man was sentenced to eight years' and four years' imprisonment respectively, to run concurrently, after being convicted by the High Court of raping and robbing a girl in Sha Tin in May 2002.

SGT Poon has earned the prosecution counsel's praise with his alertness

SGT Poon earned the praise of the prosecution counsel with his professionalism. The counsel observed: "Without his alertness, perhaps the defendant would not have been apprehended so promptly."

While being pleased to have helped bring the culprit to justice, SGT Poon told OffBeat that the credits should also go to the Sha Tin District Crime Squad that had promptly developed and circulated CCTV images to other police stations. Otherwise, the rapist could still be at large.

Back in 2002, SGT Poon was attached to the Police Tactical Unit "B" Company Platoon No. 3. On May 31, 2002, he was having a tea break when he had a look at some 10 "flyers" posted on a notice board in Mong Kok Police Station. Each "flyer" carried the photo or CCTV image of a suspect and relevant information on the case. One of the CCTV images concerned a man suspected to have committed rape and robbery.

"As I have worked in Regional Crime Unit and helped prepare identity kits of suspects, I pay special attention to CCTV images!" said SGT Poon.

The next day inside a mahjong school, SGT Poon spotted a player resembling the CCTV image of a wanted person when his platoon joined forces with the Mong Kok District Anti-Triad Squad (DATS) in carrying out an anti-vice operation.

He recalled: "The man tried to evade eye contact with me. Though he had his moustache shaved, I was pretty sure he's the man we wanted."

SGT Poon's superior, Station Sergeant Leung Wing-hang, immediately arranged to have the CCTV image brought to the scene while the operation continued in the mahjong school. After the operation had finished and the PTU and DATS had left the mahjong school, SGT Poon, SSGT Leung and Police Constable So Pak-wing continued observation outside the premises until the image arrived.

What followed next were confirmation of resemblance to the image and questioning of the suspect outside the mahjong school. SGT Poon recalled: "The CCTV image showed the rapist was wearing a pair of rubber boots. But, at that time, he was wearing a pair of slippers. My colleagues and I then asked about his work and he said he was a transport worker taking fish to markets. We immediately linked his occupation to wearing rubber boots. When we asked more questions, he became evasive."

The man was taken back to station and the case was followed up by Sha Tin District Crime Squad, which later recovered a gold pendant from the man. The pendant was later confirmed to have been stolen from the rape victim on the day of the offence.

SGT Poon does not credit the arrest with his good memory, but observes that taking a good look at suspects' photos or CCTV images and staying alert at all times will help investigation work.

SGT Poon, who is now working with the Tsim Sha Tsui Patrol Sub-Unit, has served in various posts in Kowloon West after joining the Force in 1984.