Wearing a school uniform she had bought online, Jung went to the tutor’s house.
Once inside she carried out a frenzied attack, stabbing her victim more than 100 times before dismembering the woman’s body.
Taking a taxi, she dumped some of the body parts, which had been packed into a suitcase, in remote parkland.
The driver then contacted the police and told them about a passenger with blood-soaked luggage.
Prosecutors wanted death penalty
Prosecutors had sought the death penalty for the gruesome murder, which sent shockwaves around South Korea.
Police said Jung had spent months researching online how to kill somebody and dispose of the body.
In an attempt to commit the perfect crime, she kept the victim’s mobile phone, ID card and wallet, hoping to fool the authorities that the woman had disappeared.
But Jung failed to take into account the presence of CCTV cameras that caught her entering and leaving the victim’s home.
Jung, who confessed to the crime in June, said she suffered from hallucinations.
However, the court ruled the crime had been “carefully planned and carried out, and it is difficult to accept her claim of mental and physical disorder”.
On Friday, the judge in Busan District Court said the killing had “spread fear in society that one can become a victim for no reason” and “incited a general distrust” among the community.
Although the death penalty remains legal in South Korea, the last execution took place in 1997.
