Yu-jeong Yoo, 37, was sentenced to life imprisonment, who was handed over to trial for murdering her ex-husband and abandoning her body.
The first division of the Supreme Court (Chief Judge Lee Ki-taek) confirmed the court case sentenced to life imprisonment for Ko, who was convicted of murder, corpse damage, and concealment.
The Supreme Court ruled that "the accused's statement that the victim tried to rape him at the time of the incident is not reliable."
"It is fully acknowledged that the defendant planned the crime carefully, such as searching for tools and methods of the crime, and purchasing zolpidem in advance, killing the victim according to the plan, and then destroying and hiding the body."
However, on the charges of murdering his stepson, he maintained the court's innocence judgment, saying, "There is a possibility that the victim was crushed and killed by the father who slept with, not by the accused."
Mr. Ko was handed over to trial on charges of abandoning his ex-husband A, damaging his body, and murdering his stepson.
Both the first and second trials convicted only the murder of the ex-husband and the abandonment of the body, sentenced to life imprisonment, and judged the murder of the stepson as innocent.
On May 25 last year, Mr. A secretly fed a sleeping pill to Mr. A, who visited a pension in Jeju with him for interview negotiations with his son, and was charged with killing him several times with a weapon.
In addition, they are also charged with abandoning their bodies little by little, such as throwing them into the sea by the 31st of the same month or throwing them into the garbage separation facility in apartments.
Ko admitted to the murder of Mr. A, but insisted that Mr. A was accidentally committed in the process of resisting to rape him.
However, the first and second trials judged that it was a planned murder based on the fact that no signs of sexual assault were found, and that Ko purchased sleeping pills and weapons before the death of Mr. A, and searched the Internet for'how to erase blood stains'.
Mr. Ko taught his son, who was born with Mr. A, that his remarried husband is his real father, but it was investigated that he decided to commit the crime when Mr. A's request made it impossible to avoid interview negotiations with his son.
Ko was also charged with suffocating his husband's ex-wife's son (then 4 years old) who was born on March 2, last year, while he was sleeping, but was convicted of this.
The prosecution believed that Mr. Ko committed the crime in conflict with her husband, but the court found the charges innocent because the charges were not sufficiently proven.
Meanwhile, Mr. Ko lost custody of his own son after the prosecution and also lost a divorce lawsuit filed by his spouse, the father of his stepchildren who died.