A 27-year-old air-conditioning technician on trial for a 2005 murder rode a lift up and down in the Revenue Tower, Wan Chai, waiting for a potential victim to rob before settling on a Thai tourist, the High Court heard yesterday.

So Kam-tong previously pleaded not guilty to one count of murder in the robbery and slaying of the 40-year-old Thai tourist and jewelry trader, Charitar Kamolnoranath. The woman's body was found in an air-conditioning switch room on the 33 floor of the Revenue Tower on October 24 after her disappearance on October 12.

Testifying in exchange for immunity from prosecution, 27-year-old electrical technician Kwok Chi-fai said his former colleague and classmate So revealed the events of the robbery at the Revenue Tower over a meal days after the murder.

"He told me he was in a lift waiting for a target. He went up and down the same lift. After a target appeared, there was a third passenger. When that person alighted and then the deceased was at a certain floor about to exit, (So) took out the knife," Kwok told the court through an interpreter.

"She was dragged back into the lift. He took her to an air handling room. She started to struggle and he said he accidentally injured her," the court heard.

Kwok said So had taken Kamolnoranath's banking card and had her divulge her PIN number but failed to withdraw any money when he tried the card at an ATM near his Tai Po residence.

When he returned to the air handling room, he found she had died, So allegedly told Kwok.

Kwok also said he had helped So hide the body of Kamolnoranth because he was afraid of So who had a knife with him.

Kwok was arrested in the case in 2008 for preventing the lawful disposal of a body but was later released.

Kwok said he helped So move the body to the top of an overhanging air duct in the air handling room sometime after the disappearance of Kamolnoranth on October 12 but before his (Kwok's) birthday on October 17.

On another day, So demanded Kwok meet him at the scene because he feared he had left something behind but the two did not linger when they saw another worker in the room.

Kwok's cross examination continues today.

(HK Edition 03/05/2010 page1)