The 37-year-old suspect, who admitted to burning hatred of the wealthy, made thorough preparations for his crimes, police say. He watched crime thrillers such as "Memories of Murder" and "The Silence of the Lambs", read several books on psychology, science and the human body, and ran 10 km every day to build up his physical strength. He also used different weapons to make it difficult for police to track him down.

To confuse police investigators, he used knives in seven cases in 2004 and blunt objects in four cases in 2005 and two cases this year, police said. They are also investigating whether he raped his victims after he confessed to killing women who resisted his attempts to rape them.

Police have arrested a serial killer who hit at least five random victims over the head with a blunt object and burned their bodies to erase evidence after robbing them of no more than a few thousand won. Among others, the 37-year old identified as Chung is suspected of killing two sisters and seriously injuring a third in Bongcheon-dong, Seoul last month.

Police said Chung was motivated by ¡°blind hatred of society,¡± particularly the wealthy. But he targeted anyone including disabled people, from an 18-year-old high school girl to a 47-year-old housewife. He allegedly killed five people and seriously injured eight others in attacks over the last two years.

Chung reportedly suffered from a sense of isolation and victimization since a stint in prison for theft in 1995. Police said Chung broke into homes to steal money and valuables and attempted to kill his victims by hitting them with a blunt object.

Chung, who was described as a marathon fan, picked out houses to target during all-night walks around the city. He was caught on Saturday morning in a struggle with the owner of a house he broke into.