A driver strangled his stepson with a vacuum cleaner cord so he could claim a US$200,000 (HK$1.55 million) insurance policy secretly taken out on the boy's life, a court heard yesterday. Law Wai-yin, 11, was the victim of a 'brutal and premeditated killing, callous in its execution and committed principally for financial gain', a jury heard. Prosecutor John Mullick said that on August 5 last year, Wai-yin was taken to a Sha Tin car park in a car his stepfather had borrowed. He was in the front passenger seat and was choked from behind by his stepfather, Tsang Chiu-tik, 34, the Court of First Instance heard. Mr Mullick said Tsang's friend Kum King-fung, 30, kept watch, and just before the killing raised the car bonnet so passers-by would not see what was going on. Both men have denied murdering the boy, whose body was found at a rubbish collection centre in Tai Po. Mr Mullick said that a couple of months before the killing, Tsang had forged the signature of the boy's mother on an insurance policy he had taken out on Wai-yin's life without her knowledge. The mother, Ng Siu-san, testified that on the day the boy went missing she received a phone call at work from her mother, who was worried because Wai-yin had not been to his classes. The boy's grandmother rang again after receiving a call at the family's Ma On Shan home from a man claiming to be holding Wai-yin captive. He demanded $150,000. Mr Mullick said the ransom demand was a cruel deception designed to throw the family and police off track. Ms Ng said that night she had told Tsang she was frightened of what might happen to her son. 'He told me not to be worried. He said that my son would be all right,' she said. Ms Ng told the jury that she and Tsang had been living together since May 1996. But she said Tsang had been upset that she had run up several debts and thought Wai-yin was disrespectful to her and to him. Both defendants have pleaded guilty to kidnapping. The trial continues before Madam Justice Clare-Marie Beeson.