This file photo shows Jeon Joo-hwan who was being sent to prosecution in September 2022. (Im Se-jun/The Korea Herald)

A South Korean man who stabbed his ex-coworker to death at her workplace after she refused to drop harassment charges against him was handed a life sentence in an appellate court ruling Tuesday.

Jeon Joo-hwan, 31, was accused of stalking his ex-colleague at subway operator Seoul Metro by sending over 300 text messages, blackmailing her after secretly recording a video of her and committing a revenge killing at Sindang Station, among others. He was also ordered to take a 40-hour sexual harassment prevention training program and wear a tracking device for 15 years in case he gets released from prison.

It was a heavier punishment than earlier district court rulings. Jeon was sentenced 40 years in prison for revenge murder, plus another nine years for stalking in two separate lower court rulings. The two cases were merged into one at the Seoul High Court.

Jeon and the victim started working together at Seoul Metro in 2018. He was formerly an accountant, but had a criminal record that included distributing pornography and use of violence.

Enraged by being fired and facing criminal charges, Jeon ended up tracking down the victim's residence and workplace via unauthorized access to Seoul Metro's internal network.

Jeon fatally stabbed the victim, then 28, in the women’s restroom at Sindang Station – the victim’s workplace -- a day before the court ruling for his alleged harassment.

The appellate court judges said in a ruling that there were no extenuating circumstances that could exonerate Jeon from the nation's de facto toughest sentence, considering that the heinous crime was committed during law enforcement and court proceedings "meant to protect the victim's rights."

The ruling aims to "publicly state that anyone taking an innocent life with wrongful intentions must face a consequence," it added.

The high-profile case raised the need to revise Korea's anti-stalking law. In June, the National Assembly unanimously passed a bill to eliminate the possibility for stalking and harassment offenders to negotiate an out-of-court settlement with the victim, a practice that has often left stalking victims vulnerable to coercion or retaliation.

Min Go-eun, an attorney at Counsel New Seoul Law Firm representing the Sindang Station victim's bereaved family, revealed that over 27,000 citizens' signatures were collected and presented at the appeals court in a petition calling for a heavier punishment on Jeon. Min added that she respected the ruling and hoped there would be no further murders by harassment offenders.