The police have sent the case of the Sillim stabbing rampage that resulted in one death and three injuries to the prosecution.

The 33-year-old suspect identified as Cho Seon issued an apology on Friday upon being asked about when he started planning the crime as he was being transferred to the Seoul Central District Prosecutors' Office.

Cho faces charges of murder, attempted murder, fraud and theft after he fatally stabbed a man in his 20s with a weapon over ten times near Exit Four of Sillim Station last Friday afternoon before proceeding to injure three other men in their 30s in a nearby alleyway.

The suspect stole the weapons from a grocery store some ten minutes before arriving at an area near the station by taxi, which he failed to pay for, and began a six-minute assault on victims who had no prior contact with Cho.

Cho has reportedly testified that he had planned the crimes, searched for murder methods online, and reset his mobile phone in advance in fear of his crimes being discovered.