Seo’s death poses a challenge to the investigation team, as he was considered a prime suspect in the case. They had discovered additional evidence that pointed to the suspect.

Before he died, the only evidence against Seo was a fingerprint of his found on a balcony. The bodies of the 84-year-old and his grandson were first discovered in a room with signs of arson, but were unaffected by the fire.

Recently discovered CCTV footage showed Seo in a car not registered as his personal vehicle, near the scene at around the time of the alleged crime. According to local reports, Seo was not close to the victims.

“We are thoroughly investigating potential suspects to bring the case to justice,” a police spokesperson said. “Seo was just one of the suspects.”

The two bodies were found Thursday. The elderly victim was identified by his last name Han. The case had appeared at first to be a fire accident, however, signs of a fractured skull and severe wounds were discovered on the bodies.

The motive behind the killing is still unknown.

By Jung Min-kyung (mkjung@heraldcorp.com)