HOMICIDE detectives in the United States have arrested an Asian suspected of scheming to make millions from the murders of more than 100 people in an elaborate insurance fraud. San Francisco police arrested Thuan Wu on their own doorstep after asking Hongkong officers to help in an international manhunt because they believed he was hiding in the territory. The plot was uncovered after the murder of his girlfriend's nine-year-old son. Detectives probing the seemingly senseless killing of Michael Nguyen discovered Ms Suulan Chem's boyfriend of six years would make a fortune from the schoolboy's death. And they found the 41-year-old Wu had taken out life insurance policies worth millions on more than 100 people without their knowledge. Michael was kidnapped by three Asian men from the front of his San Francisco Sunset District home early on September 2. His battered body was discovered seven hours later in a gully in Golden Gate Park, near San Francisco's Golden Gate Bridge. After Michael's death, police discovered the Vietnam-born Wu, a married man, was the beneficiary of several life insurance policies on the boy. Wu, an insurance agent, had taken out five policies on Michael's life and stood to make more than US$750,000 (HK$5.85 million) from his death. In the weeks after Michael's murder, Wu tried to collect on two policies: a US$200,000 New York Life policy with a double indemnity clause and a US$100,000 Surety Life policy. He failed to collect anything. A New York Life insurance investigation, inquiring about a policy naming Ms Chem as beneficiary, put the police on the paper trail. In the next few weeks, they learned of the other four policies. As a result investigators from the California Department of Insurance cross-referenced names and addresses of insurance policies. They discovered Wu was named as the beneficiary in more than 100 policies of his friends or relatives. Detectives contacted police in Hongkong and Canada as well as across the US after Wu disappeared. ''He has links in Hongkong and it is very likely he has fled there,'' a police spokesman then said. ''We are searching throughout the United States in case he has been unable to get out of the country and Canada because it would be easy for him to slip across the border.'' The arrest warrant charges Wu with kidnapping, robbery, presenting and attempting to present fraudulent insurance claims, conspiracy to commit murder, and murder with special circumstances, which means murder for financial gain. He was eventually arrested in San Francisco after a tip-off from a member of the public. Wu was picked up as he entered the San Francisco Motel in the Marina District of the city. He was pretending to be a Hongkong Chinese and gave the name Lin T. Chow. Wu, who underwent a five-hour videotaped interview by police, suffered an apparent seizure at the San Francisco Hall of Justice but paramedics who examined him deemed him fit. He is being held without bail and faces the death penalty if convicted. Besides taking out the five insurance policies on Michael, in which Wu named himself or his wife, Mrs Vi Tran Wu, as beneficiary, he also took out policies on almost everyone he knew, San Francisco police said. ''Wu basically opened up his personal phone book,'' a police spokesman said. ''They were people he knew - relatives, friends, and friends of relatives.'' Detective Tony Camilleri said: ''He is a greedy man and he thought he could get away with it.'' Police found a lifelong friend of Wu's was mysteriously shot in an ambush shortly after Wu named himself as the beneficiary of a policy on the man's life. Investigators said the slaying of Michael and the attempted murder of Mr Phuoc Huynh were part of an insurance fraud scheme masterminded by Wu. Wu stood to make US$300,000 if Mr Huynh had died. INSPECTOR Jim Bergstrom said a gunman shot Mr Huynh - who was described as a Vietnamese male aged about 30 - in San Francisco a year ago when he arrived for a card game Wu had invited him to attend. No-one has been arrested in the shooting. The insurance policy on Mr Huynh's life named Wu as the beneficiary ''if anything happens to Huynh''. ''Wu arranged for the policy through another agent in a way that questions the validity of the policy,'' Inspector Bergstrom said. He said the insurance information, coupled with the fact Wu had directed Mr Huynh to the spot, indicated to police Wu was guilty in the shooting. State insurance experts said it was possible for someone not to realise a policy had been taken out in his or her name if an agent filled out a fraudulent application on behalf of the person. For weeks, the investigators have been cross-referencing names and addresses of insurance policies that name the 41-year-old insurance agent or his wife as the beneficiary to determine ''whether those insured are dead or alive''. ''The numbers of such policies are still being tallied,'' said Ms Elena Stern, spokeswoman for the California State Department of Insurance. ''We are in the process still of checking all the insurance policies that he sold, in an attempt to see what else might be involved in the way of fraud.'' Investigators suspected Wu was involved with other people in a variety of insurance scams, including car insurance frauds. ''Michael Nguyen's murder is particularly disturbing. Life insurance fraud is bad enough but we're looking at cases where there was an actual death involved,'' Ms Stern said. Wu paid the annual premiums on the policies, investigators said, but at reduced cost. In the first year of a life insurance policy, the agent - in this case Wu - receives a commission of about 80 per cent of the premium for the first year. Wu even named his sisters in life insurance policies he took out. ''We believe he had one of his sisters killed,'' Detective Marvin Dean said. Wu's sister, restaurant owner Nga Tuyet O, fell to her death from the San Francisco Bay Bridge in 1991. He was unable to collect on her death because the Alameda County Coroner's office ruled it a suicide. Wu, a licensed insurance agent, sold and wrote up various insurance policies for a number of companies in San Francisco, including Surety, New York Life, Northern Life, First Capital Life and United Olympic Life. He took out the insurance policies on Michael from United Olympic, New York Life, First Capital Life, Northern Life, and added an accidental death benefit addendum to a Surety Life policy Ms Chem had taken out. Ms Chem, who was investigated in connection with her son's death, was later ruled out as a suspect. Detectives also uncovered a US$100,000 life insurance policy Wu took out on Ms Chem, indicating she might have been an intended victim. The policy named Wu's teenage son as the principal beneficiary. Inspector Bergstrom said his detectives believed Wu intended to kill Ms Chem or convince her to commit suicide so he and his wife - named as the beneficiaries next in line on the policies - could collect the money once her son was killed. They discovered Ms Chem knew nothing of the policies and that her signature had been forged on key documents. Wu, who also used the names Tom Wu and Thuan Quang Huynh, also took out a policy on his nephew, Mr Farace Troung, who is in his mid-20s. ''There are a lot of suspicious policies and we are trying to figure out what Wu has been doing,'' said Mr John Auvinen, a California State Department of Insurance fraud investigator. State insurance investigators are searching computer files of the companies involved. Ms Stern said: ''We are trying to pull up everything he was associated with. It's a time-consuming and arduous process that is ongoing.''