Kim Sang-hoon, who murdered two people after taking four people hostage on Jan. 13., planned the crime and raped his stepdaughter before killing her, the police said Wednesday.
The 46-year-old is accused of murdering his stepdaughter and her biological father after an hourslong standoff with the police at a residence in Ansan, Gyeonggi Province.
Kim insisted that he had not planned the murder or the hostage situation in advance, claiming he was provoked by police and killed his stepdaughter. But police found that he had already possessed the tools for the homicide when he visited the crime scene, said investigators at Ansan Sangrok Police Station.
"CCTV images of the adjacent areas (of the crime scene) showed that Kim bought a pair of work gloves at a store near the victim's home before breaking in," officials said. They also learned that Kim already had on him the knife he used in the crime when he entered the residence where the victims lived.
Although Kim has denied raping his stepdaughter before murdering her, forensic analysis of the girl's body discovered Kim's semen and traces of his DNA inside the body.
Investigators found that Kim was frequently violent with his wife during the seven years they lived together.
"When his wife refused to meet him or talk to him over the phone, Kim planned the cited crime. He believed that he could lure her out by taking the children hostage," police said. Police profilers have deduced that Kim is a psychopath who is deluded into believing he can control the actions and even thoughts of his wife. They said that he has very little guilt and empathy. He is also very violent and tries to rationalize his crimes, they added.
Kim is also being charged with the illegal possession of a Japanese sword. Overall, he is facing 10 different charges including homicide, rape, assault and confinement against one's will.
On Jan. 12, Kim entered the home of his wife's ex-husband and took the man's common law wife hostage. When his wife's ex-husband returned, Kim killed him with a kitchen knife he is thought to have brought from his home.
He then took the teenage girls, born between his wife and her ex-husband, hostage. He was caught after police commandos stormed the residence after a five-hour negotiation ended in failure.