A decorator who killed two prostitutes by smothering them with towels soaked in chloroform was jailed for life yesterday. Hong Tsz-yin, 27, was convicted by a jury after a retrial in the Court of First Instance of one count of murder and one of manslaughter for killing Kwan Suk-yee, 47, and Wong Amporn, 37, in January 2009. Mr Justice Michael Stuart-Moore called Hong a "sexual predator of the worst possible kind" for his "terrible deeds". In sentencing, the judge said: "There is probably no section of society of Hong Kong that is in need of protection more than sex workers who operate alone." He said prostitutes lived in constant fear of meeting someone who appeared to be an ordinary client but turned out to be a sexual predator. "Despite your average appearance, you displayed an extreme nature," he told Hong, who showed little remorse. The court heard that Hong killed the two women three weeks apart. On each occasion, he had unprotected sex with the victims before pushing a towel soaked with concentrated chloroform into their faces, suffocating them. He then stole various items, including a mobile phone and an Octopus card, from their flats in Kwun Tong and To Kwa Wan. Hong was arrested four days after the second killing, the court heard. Police were led to him after he sold the phone to a second-hand dealer in Kwun Tong for HK$1,950. The judge imposed a jail term of 14 years for the manslaughter and an automatic life sentence for murder. He praised Wong Chun-yue, who was a senior inspector when he arrested Hong, and Detective Sergeant Tam Kai-fai for their skill in handling the case. "The most efficient, fair and thorough police investigation brought the defendant to justice in just four days after the second killing," he said. The judge asked the prosecutors to make sure that his commendation was passed on to the Commissioner of Police. Wong, who is now a chief inspector, has been with the force for 11 years. The Court of Appeal quashed Hong's first conviction for murder and life imprisonment, ruling that Madam Justice Maggie Poon Man-kay erred in her direction to the jury as she summed up evidence in the case. Appeal judge Mr Justice Michael Hartmann wrote: "Every defendant is entitled to have his defence - however implausible, even if it appears to be an affront to common sense - fairly and accurately put to the jury for its consideration."